Introduction: Oak & Concrete Dining Room Table
This is one of those projects that started off with one idea and has evolved into something else over a 3 year period due to other projects coming and going, indecisiveness, costs and other things.
So about 5-6 years ago I bought a house, in that house is a dining room, but alas I had no dining room table. I wanted something fairly large to fit the space and I liked the idea of a large hardwood slab for the top.
At the time I had an idea to encase this slab in resin and polish it up nice and shiny, maybe add some inclusions to the resin too. Back then these resin tables were uncommon and I hadn't ever seen anything like that, just resin coated ones, unlike now where they're literally everywhere online and I've even made one myself for a coffee table using a Cherry slab (see other Instructable)
Anyway after a few years we'd decorated the dining room the time had come to build a table, sadly I had nothing and no one near me that I knew of that sold large wood slabs so I scoured the internet and eventually came across a chap in Cornwall on eBay selling 6 massive Oak slabs he's cut down years ago and had lying around ever since, drawback was Cornwall is 450 miles from where I live and these slabs were all 5-6ft tall and 40-50mm thick. Still I bought them all (why wouldn't you at £40 each?) and arranged a courier man to collect them all for me and bring them 450 miles back to my house .
With all the slabs back home I chose a good sized and shaped one and the 3 year build commenced!
Unfortunately at the beginning of this build I was so eager to get going I forgot to take photographs as I was progressing. As a result I have no photos at all of me making the legs, which took a while to complete, but I'll go through what I did and explain all my steps when it comes to that section.
Step 1: Materials, Tools & Equipment
Below is a list of everything I used to build this table as far as I can remember, this build was ongoing for 3 years so I may of missed out some stuff. As always this isn't a list of everything you absolutely need as there's always various ways of doing anything usually, but these are the things I used in my build.
- Oak Slab
- Old Oak Flooring
- Beech Lengths
- White Cement
- White Aquarium Sand
- Concrete Reinforcing Fibres
- 150mm Galvanised Coach Bolts
- Fine Glitter
- Decorative Stone Chippings
- 2400mm x 1220mm x 11mm Plywood Sheet
- 2400mm x 70mm x 50mm Pine Lengths x3
- Silicone Sealant
- Wood Glue - Gorilla / Titebond
- Epoxy Resin - Glass Cast E50/ Glass Cast 3
Tools & Equipment
- Router & Homemade Sleds
- Flat Bottomed Router Bit 38mm
- Circular Saw
- Table Saw
- Chop/Mitre Saw
- Mortise Machine
- Random Orbit Sander x3 ( over 3 years 2 blew up with constant use)
- Wood Turning Lathe
- Belt Sander
- 125mm Angle Grinder
- Stone Polishing Pads 50-2000 Grit
- Stone Grinding Wheel
- Varying Grit Sanding Pads 80-400 Grit
- Ring Spanners
- Socket Set
- Drills - Cordless/Electric
- Drill Bits
- Pointing Trowel
- Mixing Paddle
- Concrete Float
- Japanese Pull Saw
Step 2: Levelling the Slab
To begin this saga I first chose one of my 6 slabs that I'd bought for the tables top. I wanted one that was fairly flat and straight, but also long and wide to give me a good sized table that at least 4 people could use.
The one I chose had all these attributes and had some nice features where a branch or something had protruded when it was still a tree. Because the guy had, had these slabs so long when I bought them each one was covered in years of dirt and grime, so to see what I was dealing with underneath all this I took my grinder with a backing pad attached and using some 100 grit sanding discs to quickly sand away all the muck to reveal the wood underneath.
The dirt was very well ingrained in so it took some time to get down to 'clean' timber, however due to age and the nature of how the slabs were cut they were also very uneven so the grinder was leaving high and low spots, not ideal for a flat table surface.
I needed a way of removing all the dirt and cleaning up the slabs whilst also making them as flat as possible. After some research online due to only having a 300mm wide thicknesser (not an industrial sized one you see people online and Instgram etc using these days) I came across router sleds and decided to build one myself for this project.
It allowed me to fit a flat cutting bit in my router and with the uneven slab packed underneath to stop it moving and rocking, pass the router back and forth over the slab removing material at a level height all the way across, flattening the slab. I won't go in to too much detail how I made this sled, you can kinda see from the photos, but I did end up making 2 versions.
For version 1 I used plywood for the sled base and upon using it on the first side of my slab the plywood was sagging in the middle slightly, unbeknown to me due to the weight of my router. This resulted in some parts of the slab been cut away deeper than other parts and gave an uneven finish once I'd gone over the entire surface, disaster.
With this I built version 2 using an old steel CD rack for the frame that happened to be the same width as my router base and upon testing did not sag when I passed the weight of the router across it. To make sure however I used another one of my smaller slabs as a test piece so as not to ruin my chosen table top piece further should it go wrong again.
With the new sled and test slab set up I passed the router over the face of the slab cutting away to a depth of around 5mm at a time until all the high spots were removed and the slab was level right the way across. I flipped the test slab and repeated this on the other side and when I was done I had a nice flat smooth surface on both sides that just required some sanding to finish off and remove the tooling marks.
Confident my sled 2.0 now worked I swapped in my table top slab, packed it up to stop it moving and using the new sled routed the material away. With one side done I could flip the slab and repeat for the second side. Unfortunately because of my earlier mistake I couldn't fully get out all the low spots, as the slab would have been to thin and cut through to the other side, so I just decided to get as near as possible and resolve this later.
My test slab however was pretty much perfect after sanding so I polished it up and gave it to my dad for a coffee table top. (Already I'm making other stuff instead of my table)
With my table top slab as level as I could get it for now I used my original random orbit sander to smooth out the router marks left behind and finish the top to a smooth finish, working up to 240 grit paper once all the tooling marks had been sanded out.
Step 3: Legs Prepartion
As I said at the beginning, due to my eagerness to crack on with the project I forgot to take photos of the leg build process but I've tried to mock some images and diagrams up and I'll go through what I did.
To make the legs I used some old tongue and groove engineered oak flooring boards that I was given from a house where the owner decided to change the floor, but was just going to throw all the old solid oak away, madness.
The boards were not in great condition when I got them with the majority of them covered in various flooring adhesives on the bottom and having nails through the sides where they'd been tacked together. The top surface of the boards however weren't in bad condition fairly flat and straight they just had the hard engineered finish on that needed sanding off, so I had a starting point at least.
To start with I used various sharp scraping tools, paint scrapers, knives, chisels etc to try and remove as much adhesive as possible from the back of the boards. I found the best way was putting a board in a bucket and running a chisel down it scraping off the adhesive in to the bucket both collecting the mess and cleaning the board at the same time.
I then used a stud/pipe/cable finder run along the length of each board to identify where any nails were in the boards edges. I was going to run these through the planer eventually so didn't want any metal that could damage my blades. Using a hammer, screwdriver and pliers I removed any nails I found and stacked up the prepared boards ready for planing.
With a pile of boards cleaned off as best I could, I used my thicknesser to remove any remaining adhesive and remove the floorings grooves on the bottom side so I had a flat surface. I ran each board through the thicknesser using the engineered side of the boards face down so that the bottom of each board was cut flat and parallel to it. After a few passes of each board, lowering the thicknesser blades each time all the adhesive was removed and any ridges gone.
I could now pass the engineered side through to remove that hard shiny finish before starting to glue up several of these boards to make a block the length I wanted each of my legs. My design for the legs was a kind of 'A' shape, so in total I glued up 6 blocks made from multiple of the planed oak floor boards. I made 4 long ones that would be the legs and 2 shorter ones that would be cross members and form the top of my 'A' shape.
Using my Titebond I glued up the boards, clamped them and left them overnight to dry.
Once dry I had 6 chunks of oak for my legs but each chunk still had the tongue and grooves along each side from its past life as flooring. To remove these and give myself square timber lengths I used my planer and thicknesser, lining up one of the flat faces to the fence and passing the tongue or grooved side over the blades, until I was down to the solid timber and had another smooth solid face. I repeated this on all 6 chunks on both the tongue and the grooved sides until all 6 chunks were flat and square.
Step 4: Leg Joinery
To form the 'A' shape of my legs each one was made up of 3 of the oak blocks, two long ones for the sides of the 'A' (the legs) and a short one for the top brace, there was then a round beech support spindle mid way down.
In order to join all the oak elements of the legs together I opted to use mortise and tenon joints at the top that would be hidden once the table top was on.
With the basic oak blocks already made, in order to get the shape and angles of my legs the same for both sets, I drew out an 'A' shaped template to the size I wanted the legs to be on a sheet of plywood. This allowed me to lay the pieces over the top when marking and gluing to ensure they would be the same size once cut and fastened together.
To mark out my mortise & tenons I laid out two legs over the template and marked there lengths on the blocks. Using my chop saw I could then cut these to length and re-lay them on the template. Next I lined up the oak top brace over the top of the legs and again marked the length that this block needed to be, cutting it down with the chop saw as before.
With the top member cut I could over lay this on the legs again and marking from underneath run my pencil along the inside edge of the legs to mark the angle at which the top brace meets the inside faces of each leg giving me the shoulder location of my tenons. I could also draw around the outside of the top member marking the legs as to where the mortises would go. With these lines drawn I could then extend them round the pieces to get the final positions and sizes of both the mortise and tenons.
With all the pieces marked out I began my cutting my mortise joints in the top of each leg. To do this I used my mortise machine, lining the top of the leg up so that the pencil mark was in line with the edge of my chisel, I could then slide the leg along the fence bring the chisel down to cut material away and repeat for as long as the joint required. I then moved the fence back so the chisel lined up on the other side and repeated the cuts again, doing this for both legs.
To cut the tenons I used my tenon saw, because these would need to be angled to fit the final 'A' shape of the legs I found this easier than trying to use the mortise machine again. To begin I started cutting along the angled lines I'd drawn on the face of each top brace, cutting down to the correct depth as marked on the other two faces. With the depth reached I could then start cutting down from the end of the top brace until I reached where I'd previously just cut. Removing these two chucks of timber I was left with my tenon sticking out the end of the top brace, I could now repeat this on the other side.
To finish the tenon joints I needed to cut the ends at an angle so they fit inside the mortises I'd already cut. The angles were the same as for the tenons shoulders so I measured the depth of my mortises and transferred those onto the tenons, I then cut the tenons with the tenon saw giving me the correct angle.
To test my joints I laid out the pieces on the template again, this time dry fitting the joints to make sure everything aligned, tidying anything up with my chisel where it was tight or uneven. I could now repeat all the above steps for the second set of legs and with everything eventually correct I could now make the beech spindles.
Step 5: Leg Spindles
To make the beech spindles I used my wood lathe. The spindles were made from 40mm x 40mm beech lengths I had leftover from another project. The spindles were pretty easy to make as they were fairly simple, I just wanted something to add a bit more support to the legs.
I marked each end of the beech drawing corner to corner to form an 'X' giving me the centre of each end. With these centres I could then mount the beech between centres on my lathe.
Switching the lathe on the beech ran true and straight and I could begin removing material to get the lengths from square to round, moving my tool rest along the lathe bed to turn the spindles evenly. As they started to round I narrowed the centre of the spindles slightly to give shape and add a bit of detail.
Once I was happy with the shape of my first spindle I sanded it smooth and applied some clear wax, polishing it to a shine on the lathe. I could then mount my second piece of beech and produce the second spindle.
To ensure the second was the same as the first I set some steel calipers to the same diameter and used these whilst turning to check I was cutting to the correct depth. To cut the narrower part of the spindle I again used the calipers as well as my eye to follow the shape of the first spindle as close as I could. With the second as close as it was getting to the first I sanded it smooth and waxed it as I had before, removing it from the lathe once smooth and shiny.
To attach these spindles to the legs I measured down the centre of each inside leg face to the mid point, I then used my pillar drill with a forstner bit in matching the diameter of the spindles to drill a hole into each leg that would hold the spindles in place, because the legs would be 'A' shaped however the holes needed to be angled too, so I made a wedge the same angle as the cross members tenon shoulders. I could then place this wedge under the leg under the drill press, so that as I drilled down the timber was angled and the hole cut would match the angle the legs would be set at. I repeated for the other side before placing everything back on the template for one final check.
Step 6: Leg Shaping and Assembly
With all my leg parts cut I wanted each of my legs to have a taper to them, so I made a taper jig using some toggle clamps, plywood and some scrap pine. Each leg could then be clamped to it and ran over the table saw to produce the taper.
To do this I simply measured and marked the base of my legs at the thickness I wanted it in the centre of the leg and drew a line along the length of the leg to the top outside edge. This gave a diagonal line across the outer leg face I could line up with the base edge of my jig, I could then move the pine support block and clamp the oak in place causing the rest of the leg to overhang over the plywood base.
I could now set up my table saw with the fence set away from the blade at the same width as the plywood base of the jig, the piece of the leg over hanging would then be cut off once passed through the saw giving me my taper. I could then repeat this with all the legs so that they all had the exact same taper cut.
Once I'd cut one side of each leg, I could repeat for the other side by flipping the leg over and using the piece I'd just cut away packed between the jig support block and the taper of the leg. This mimicked the square shape I had started with and ensured that the legs second side was positioned the same as the first one, so that when I cut it each side of the legs had identical tapers.
With one side of one leg tapered I was easy to repeat for the rest of them as I was just a matter of clamp, cut, flip, clamp, cut until all 4 individual legs were cut and tapered.
All I had to do now was lay everything out back on the template and glue everything up, clamping it all together to give me my two 'A' shapes. Because of my lack of clamps at this point I glued up each leg separately lining each up on the template first before clamping the joints tight together. I left each set of legs overnight for the glue to set.
Step 7: Back to the Top
With the legs all made I could now focus my attention back on the top. It was pretty much flat at this point just needed to be cut to length to make both ends of the slab square which I did using my circular saw.
My original plan for the top was to encase the entire thing in clear resin with some slight pigmentation and inclusions etc. This would level out the few imperfections in the surface and give me a nice finish.
However I have since made my smaller coffee table top using cherry and resin and it cost me a small fortune, as it just drank resin and this table top is around 50% bigger than that so I was reluctant to use resin again in such a vast quantity at this point as I simply didn't have the money.
After a lot of thinking what to do and looking for other options I finally settled on using concrete to fill the gap along the live edge of the slab to give me a rectangular shaped top and then coat the surface with resin to seal the whole thing. I didn't want the standard grey looking concrete finish however as it wouldn't really fit the décor of the room that the table was to go in to.
Instead I wanted a bright white concrete finish, but this wouldn't be as easy to achieve. Online these days you can buy concrete counter top kits if you wish in a multitude of colours, including white where you basically just add water and mix. However these mixes are usually only in small quantities and are no cheaper than the vast resin quantity I couldn't afford.
I had no intention of buying a ready made solution anyway, I prefer to make my own, but reading about them did help me decide what to add in to my mix.
Step 8: Concrete Materials
The basics of concrete are sand, cement, some form of aggregate and water and I've made concrete loads of times before, but mainly for building purposes, fences, drives, foundations etc, but after reading online you can add a multitude of other things to help with strength, cracking, shrinking etc depending on what you use your concrete for.
As I was combining mine with the oak slab it needed to be strong, not crack and have a nice finish, but because I'd chosen white as my colour I'd straightway made it more difficult for myself, as even adding something with a slight pigment could alter the final colour of the concrete, so with that I mind I set out buying my materials.
Luckily white cement is readily available from B&Q or Wickes near where I live as its used for lime mortar or plaster in old buildings and is bright white in colour. For the aggregate part of it I picked up some small (2-3mm) blue and green glass chippings online, these matched the colour of the décor and would add some interest to the concrete. I also bought some larger white stone chippings to add a bit more strength to the mix and bulk it out.
From my online research I also bought some fiberglass strands and some concrete plasticiser, (again from B&Q) these would help stop the concrete from shrinking and ultimately cracking once dry, as well as adding more strength which I'd need when in constant use as a table.
For the sand it was a bit more difficult, some mixes use sharp sand usually for construction, but this has tiny stones and grit in, not to mention its dark brown and would colour my bright white cement a coffee colour. Regular building sand is a golden colour, so whilst the texture is fine, again it would pigment my cement a yellowy brown. There's something called play pit sand which is like a fine building sand but it was a lot paler in colour looking at it, but still yellowy and I didn't want to take the risk of ending up with a magnolia coloured concrete top :/
At this point I had a lightbulb moment and changed my search and instead looked for aquarium sand. I was able to find 25kg bags of fine white aquarium sand online that matched the colour of my cement and should be perfect, no pigmentation when mixed keeping the colour I wanted, so I ordered some.
I also ordered some fine metallic blue and silver glitter to add to the mix for a bit more jazz, because why not, I was going to put some in my resin had I gone that route so I'll just bang some in here instead.
Step 9: Slab and Mould Preparation
With all my concrete materials gathered I was ready to mix and pour. Before that however I needed to make a mould to pour into.
The mould I made was just a sheet of plywood and 4 pine strips to form a rectangle. First I cut the plywood to the width I wanted my finished table top plus the thickness of two pine strips. The length was the length of the slab plus two pine strip thickness.
The thickness of my slab was around 40mm so I made sure that my pine stripping was also 40mm wide, that way once the concrete was poured I could run a board along the top of the mold to scrape off excess mixture making it level with the slab.
With the plywood cut, I cut my pine strips to match and marked along the edge of the ply where the strips would sit. I then drilled a series of holes all the way round the ply to screw the strips down from underneath.
Before screwing the pine down I applied silicone sealant to the underside of the strips to stop any water leaking out when the concrete was poured. I could now line up the strips and screw through from underneath to secure each one to the plywood base.
Whilst my silicone was drying on the mould I added some reinforcing to my oak, something that the concrete could hold on to so that it didn't just fall off the live edge once removed from the mould.
The reinforcing I chose was coach bolts 150mm long, I drilled into my live edge on both sides of my slab at equal intervals and then screwed in the bolts using a socket wrench. The width of my concrete from the outside edge varied due to the live edge of the oak, but leaving an 70mm portion of the bolt sticking out seemed enough to cover this variation.
At one end of the slab it narrowed to around 20mm thick, so here instead of a coach bolt I used a long 150mm screw as it had a thinner shank and head and was less of a risk of splitting the timber when screwing in as, well as showing through the concrete.
As I said I used a socket wrench to get the bolts to the 80mm depth, however due to the hardness of the timber on the final bolt the force I needed to get it in caused the bolt to shear off, thankfully you'd never see this once the concrete was in as I had no way to get it back out, so I drilled another hole and screwed another in next to it, but it goes to show the hardness of this slab.
With all the bolts in place and my mould dry I applied a bead of silicone along the top face of the slab, (this would go on the bottom of the mould) to stop any concrete leaking under the slab. I then flipped the slab and clamped it in to the middle of my mould so that the silicone would make contact and hold the slab in place. I could now leave this to dry overnight so the silicone set.
Step 10: Concrete Mix & Pour
With my mould and slab ready it was time to mix my concrete. I had decided on a 1:2:1 ratio (1 part cement : 2 parts sand : 1 part aggregate) and used a 3L measuring jug to measure out my materials in to a larger rubber bucket.
With the sand, cement, coloured glass, white stone, fibres and glitter in the bucket I gave the dry ingredients a mix round with a spade and a mixing paddle in my electric drill so they were all combined evenly. My next step was to add the plasticiser and the water. Upon opening the plasticiser and pouring out my required amount I was shocked to see it a bright reddish brown colour I assumed it'd be clear, so before pouring it in my mix and making pink concrete I first mixed a little bit with some of the white cement and water as a test, thankfully it made no difference to the colour so I poured what I'd measured out in to my main mix and topped it up with water a little at a time.
I mixed the concrete with my spade and paddle again adding more water as necessary to get a good consistency making sure all the dry ingredients were mixing in with the wet. When I was happy with it I did a little slump test to see if the concrete would hold its own weight. To do this I used an old pot and filled it with some of my mix, I then emptied this out on a flat surface. If I'd made my mixture to wet, once I removed the pot the mix would slump too far down to a pancake like shape and would mean my top is likely to crack whilst drying. Ideally I needed it to hold its shape after removing the pot so it would set strong and crack free.
I filled the pot, inverted it on to my flat surface and after a few taps the pot came away, the concrete just sat there no pancake shape, no deformation so I was happy my mix was right and that I'd get a good strong top.
With the consistency checked I began to pour my mix in to my mould around the slab and used a trowel to push it in to place, because my mixture was fairly thick I had to place it in rather than pour for the most part, tamping it down with a piece of timber running across the top of the mould and smoothing off with a float. I could of added more water so it poured easier but I didn't want to compromise the strength.
With the sides of the mould filled full I 'sawed' a piece of flat timber back and forth across the top of the mould to level off any excess concrete and get a flat surface. I then took my rectangular orbital sander with no sanding pads in and ran it along the sides of the mould to vibrate it and settle the concrete within, hopefully removing any trapped air bubbles so I had a smooth finish once released.
After 20 minutes of vibrating and tapping the mould with a rubber mallet I left it to set for a week in the garage.
Step 11: De-Moulding
After a week of been sat in the garage curing I turned the mould over and removed all the screws holding the pine strips in place so that I could remove them and free my table top.
Upon removing the strips I could see that there were a lot of little air bubbles that had remained trapped in my mix despite all the vibrating that would need to be fixed. There was also a lot on the bottom where the air had bubbled up through, but I wasn't too worried about these as I could sand those back and you wouldn't see underneath anyway
With the strips off I then flipped the mould back over to try and peel off the plywood base that was stuck to the slab with the silicone, stuck very well as it turned out this top was heavy but didn't come away from the ply under its own weight! I was able to pry it off however and reveal the surface underneath. It seemed a bit flaky and crumbly initially after peeling off the silicone and I was slightly worried, mainly because I'd used silica aquarium sand and had no idea how it would bond with the cement and timber, but after cleaning that away it seemed underneath to be okay.
I could see the coloured glass showing through in parts as well as the white stone and there was some air bubbles and voids that'd need filling. Unfortunately you couldn't really see any of the glitter I'd put in to give it that sparkle it had all just got lost, in hindsight I should of added around 200% more glitter than I did.
The main thing was though it seemed to have worked, my concrete was set hard with no cracks, it was white and resembled a table top. The next thing to do was sand it back and smooth it down.
Step 12: Beautifying
So my table top was set and released and now it needed polishing smooth, because it was concrete I needed some special pads to be able to do this. Initially I tried using my random orbital sander number two and standard sanding dics, however the concrete just wore the regular pads away and it was also evident that orbital sander number 2 was on its last legs, immediately dropping in power under any load :( This was likely due to the hard life its had, in constant use sanding back hardwood, it did well to last through my recent bed build.
Instead I ordered some resin bonded stone and concrete diamond polishing pads online, varying in grits between 50-2000. When they arrived I needed to use my 125mm grinder with a Velcro backing pad to fix the pads on and do the sanding/polishing, as I don't own a polisher sadly and my second orbital sander had just died. Due to this I decided to move outside as I've no extraction on my grinder and a 10 second test of the pad on the concrete inside literally filled my garage with dust, so I got some saw horses out and set up the top outside.
To remove initial material and reveal the coloured inclusions within the concrete I first used a diamond grinding wheel, this thing is powerful and if you're not careful it can tear into the surface in seconds and do a lot of damage. I made sure I had my handle attached to the grinder so I could better control it and introduced the wheel to the surface of the table slowly, starting on the underside so any disasters could be hidden. The wheel immediately removes material from the surface and quite quickly I got down to the inclusions. I passed over the bottom side of the table before flipping it and repeating on the top taking extra care here as a mistake here could ruin the final piece.
With the surface layer of concrete removed I could now switch the wheel for a backing pad and use the resin discs to finish sanding/polishing the concrete.
I started with 50 grit discs to remove any marks left by the grinding wheel and get the concrete flat and fairly smooth, I worked slowly over the surface of the table going back and forth until I was happy with the finish, flipping the top and doing the other side once finished.
I will say the grinder was not an ideal tool for this, it is very powerful, gives a lot of vibration feedback hurting your hands with prolonged use and has a tendency to get very hot. Now I was working in 20 degree sun at the time, but one drawback with this heat build up aside from possible tool damage was that the grease in the gearbox that transfers the power from the motor to the head started to become liquid, as a result it would run down the spindle shaft and the centrifugal force of it spinning threw this liquid grease out across the table top, the very white table top leaving black splashes of grease everywhere, which required even more sanding to get out. I tried just wiping the grease away from the spindle and starting again but it ran out every few minutes with the heat and it was clear the grinder was no longer an option.
In the short term I used the sanding discs by hand going up and down the length of the table to smooth out the concrete, but this was very laborious and time consuming. In the end I bit the bullet and went and got new random orbit sander the third to try and speed up the process a bit and get a more consistent finish. I thought about buying a polisher instead but I need the sander more as I use it all the time in every thing I make.
With my new sander bought I went back to using the discs to polish the concrete, unfortunately the weather had now taken a turn for the worse so I had to move back inside mid rain storm. Once inside it was clear both the grease from my grinder and the rain had done more staining than I thought to the oak and the whole slab looked dirty, so I pulled out my belt sander and gave the whole slab front and back a going over with 80 grit belts to remove all the stains, it was immediately clear how dirty it was when I compared the sanded areas to the non sanded ones.
With the oak sanded I then carried on working the concrete with my orbital sander using the 50-400 grit pads to sand it smooth. Whilst sanding I noticed there were still a lot of little voids in the concrete where air bubbles had been trapped, for now I just left them alone and concentrated on the main surface and getting that looking right as hopefully the resin coat later would fill these voids and after a couple of hours with the sander it felt flat and smooth enough so I gave the oak a final sand over with 240 grit and called it done on the sanding for now.
Step 13: Attaching the Legs (1st Time)
Now my top was getting there, I decided now would be a good time to check the legs fitted and that the top was level once they were. Now I made the legs a long while ago now (3 years ago) and they needed a little bit of finishing before I could attach them.
When I glued the legs using the mortise joints at top of each set of legs I had a slight overhang if you will where my angled legs overhung the top square tenoned piece. This meant offering the legs up to the underside of the table they didn't sit flat and instead sat on these overhanging edges. To make the legs flat I just ran my Japanese pull saw along the flat edge on the top of my legs to remove these small overhangs. The Japanese saw was ideal for this as its thin blade cuts close to the wood and allowed even the slightest material removal.
With the legs now sitting flat on the table tops base I could mark up there positions.
To begin I stated by measuring and marking the centre point on each set of legs, I then measured in 300mm from each end of my table top and drew a line across the slab to mark how far in the legs would sit. 300mm seemed like a good inset for the legs and would give enough room for 4 people to sit round the table. With the line drawn across I could then mark the centre point of this line which was 400mm as my table is 800mm wide.
The next step was to now mark the legs so that I could drill holes to allow them to be screwed/bolted to the table top. Due to the weight of the top at this point I decided not to skimp on the fixings so marked three equal lines across the legs and marked two points on each line giving me marks for 6 holes on each leg, hopefully enough to hold them firm to the top.
I then used my bradawl to mark each holes centre and give the drill something to locate to. With everything marked I first drilled a pilot hole followed by a larger 6mm bit to widen the holes and allow the screws to pass through. Finally I used a countersink bit to countersink each hole so that my screw heads sat flush once screwed in.
Once all my holes were drilled I could now line up the centre marks on my legs with the centre marks on the bottom of the table top, lining them up I then used a screw in each of the holes in the legs and a mallet to tap each screw and mark the top so that I could drill more pilot holes in the top making it easier to screw in to the oak.
To attach the legs I was using 65mm screws, 6 in each. However due to weight of my table screwing the legs on now as it was face up on my bench would mean it would be very difficult to then flip over on to the legs without damaging them, so instead I placed my top face up on my saw horses so the pilot holes were underneath. My saw horses stand taller than my legs so this allowed me to crouch underneath the top with the legs and screw up through from underneath simply lining up the holes with the end of the screws fed through the holes in the legs. I could then remove the saw horses from underneath and the table would then be stood on its own legs
Step 14: Resin Pour Preparation
Now that I had tested that the legs fitted okay I was ready to start finishing my top.
To do this I planned to cover it in resin this would allow all the little voids in the concrete as well as cracks and holes in the oak to be filled and give me a nice flat surface as well as sealing the whole thing. Before I did the pour however I first made a mould to go around my top to stop the resin from leaking out everywhere.
To make the mould I simply used some strips of soft wood covered with packing tape to stop the resin sticking to them once poured. The mould itself was basically a large frame that sat underneath the top but left enough of a gap all the way round for the resin to run down the side and seal the edges of the concrete. This frame was then stuck to the slab from underneath using silicone to seal it to the surface and provide a barrier to stop the resin.
My first step was measuring the width and length of my top which was 1800mm x 800mm, in order to have a gap all the way round my tops edges I cut 4 lengths of pine for the mould sides on my chop saw, 2 at 1805mm and 2 at 765mm. The smaller pieces sat inside of the two longer pieces and these were 20mm wide plus I wanted a 2.5mm gap for the resin either side (800mm-(2x 20mm)+(2 x 2.5mm)) = 765mm.
With all four sides cut I then covered them with packing tape along the faces and edges that would come into contact with the resin. I then drilled 2 pilot holes in the ends of both long pieces and applied silicone sealant to the ends of the smaller pieces, this would stop resin leaking between where the joint met. I then screwed all four pieces together to form a large rectangle and cleaned up any excess silicone squeezed out from the corners.
Now that I had a frame to go around the sides of the table top I needed to build a second that would sit underneath, flat to the surface and screw to the first frame to stop resin leaking out from the bottom. To achieve this I again used pine strips covered with packing tape but flipped 90 degrees so that the wide face of the strip sat under the table top forming a L shaped cross section.
I cut and taped these strips in the same way as before making sure tape was on any surfaces where resin could come into contact. I then drilled a series of pilot holes along each length, 10mm in from one edge of each strip this would allow me to screw through and into the centre of the other frame attaching both frames together. Once the holes were drilled I then applied silicone to the underside of my first frame all the way around, so that when I screwed my new frame pieces to it a seal would be made stopping resin leaking out.
With everything screwed together I now had one big picture frame basically that the table top would sit in centrally leaving a 2.5mm gap all the way round. Some of the silicone had squeezed out of the joints so I ran my finger along the inside of the frame to make sure all the gaps were filled and wiped off any remaining excess silicone.
Now I had the slab fitting in the frame I still needed to cover over the cracks and holes in the oak, otherwise when I poured the resin it would just leak through these and waste my resin. The two main areas for concern were a split running the length of the table top and a large hole where a branch would have protruded when it was a tree. To cover these I used some boards, again covered in packing tape to stop them sticking and stuck them to the underneath of the top using silicone close to the holes/splits to stop resin running under the slab and away from the areas I needed to fill.
Once the holes were taken care of I could then seal all the way around the frame where the slab would sit move it in to position so the 2.5mm gap was equal all the way around and clamp it in place until the silicone dried giving me a resin proof barrier that would stop it all leaking out once poured.
Step 15: Resin Mixes & Pours
Okay so my table top had been sat in its frame long enough and the silicone had dried, it was now time to begin pouring the resin. I had to do this in two stages, first I did a sealing coat/pour then did a final pour.
The resin I chose was GlassCast from easy composites. They do 3 kinds of GlassCast epoxy resin and I used a combination of two of them, GlassCast 50 and GlassCast 3. The 50 allows thick castings which I needed for my holes and splits in the oak and I had previously used this in my coffee table build with good results. The 3 I would then pour over the top for the sealing coat. I ordered 2 litres of each type of resin and hoped it would be enough.
I was nervous before this stage as when I did my coffee table build last year the resin stage was a nightmare and everything went wrong, but I'd learned from doing that build so was better prepared this time around and determined to get it right.
Before I mixed the resin I moved my table top from the garage in to my dining room (with some help, this thing is heavy) I sat the top on some oak blocks sat on some polythene sheet so it was raised off the floor allowing me to see if any leaks occurred once pouring started and if they did the polythene would protect my carpet. I moved it for two reasons, one because my garage floor isn't level so the pour would result in an uneven finish and two the resin cures better in temperatures closer to 20 degrees. The weather was colder at the time of the pour despite it being summer possibly clouding the resin (something I learnt on my coffee table build :( ) and it was raining hard and I didn't want any excess moisture in the air which could affect the clarity and cure of the resin either.
With the table top moved I checked it was level on the floor and went to mix up the first batch of resin.
My first batch was the sealing coat, as the wood is porous if I did a big pour straightaway most of it would be lost and absorbed into the oak (again lessons learned from the coffee table). So with this in mind I mixed up some of the GlassCast 50, its a 2 to 1 ratio and for this initial mix I made up 600ml of resin, so I used 400ml of resin and 200ml of hardener. To mix it together well I made a mixing paddle using some aluminium garden wire twisted together that fitted in my cordless drill. Using this I could combine the two parts quickly and evenly making sure everything was combined thoroughly.
With the resin mixed I then used a paintbrush to apply the resin to the surface of my table top making sure to paint it over the entire surface getting into any voids and rough areas. Once the surface was covered I used the remaining resin to pour into the cracks and the large hole, filling them about halfway full. Looking underneath the top at this stage I could see no leaks, thankfully my mould was holding, so I left this sealing to coat to cure. It needed to get to 'stage B' which is where the resin is still slightly tacky but not wet and you can't leave marks by touching it with your finger, at this point the next layer can still chemically bond, if it hardens I'd need to sand back this first coat to create a mechanical bond for the second layer instead, something I didn't want to do (coffee table again).
This first sealing coat I applied around 12pm and before I went to bed at around 2am it was about there, but still slightly too tacky. So as not to miss my chemical bond window I got up at 6am to check it again and at this point I had reached 'stage B' and the next layer needed pouring. In all the first coat had taken around 18 hours to cure, it could have been quicker/slower depending on room temperature.
For my next layer of resin I mixed up some more GlassCast 50, the remaining 400ml of my first litre to fill up the large hole and cracks level to the surface and I mixed up 2 litres of the GlassCast 3, in 1 litre batches to cover the whole table top. To make the top more interesting and add some colour and sparkle to these mixes I added some fine blue glitter. The stuff I added to the concrete earlier had failed to show through so I thought I'd add some here instead.
The resin was mixed in the same way as before, 2:1 ratio mixing with my homemade drill paddle, only this time I dumped in some glitter. First I mixed up the GlassCast 50 and poured this mix in to all the large remaining voids on the top. Once poured some air bubbles started escaping from the mix, so I used my blowtorch ran quickly over the top to burst these bubbles and give back the clear flat finish. I then mixed up 1 litre of the GlassCast 3, added some glitter and poured this over the whole table top before going and mixing up another litre straightaway and poring that over too. It was easier to make smaller batches of resin as its quicker to mix and easier to control pours rather than having a huge bucket full of the stuff.
With my resin poured over the table top I then used a pointed tooth edged scraper to smooth the resin evenly over the top and fill in any parts where the resin hadn't ran too. Looking across the top of the table for the reflection of the resin I could see dry spots where the resin hadn't flowed and use my scraper to push some to that area ensuring the whole surface was coated evenly and resin was running down the sides of the mould to coat the edges of the top as well.
Once the resin was across the whole top I used my blowtorch again to pop any bubbles that had formed and left it to cure again. I checked back every hour or so to look for new bubbles and pop any with my blowtorch that had formed so that when it was cured hard I had no imperfections in the surface caused by these bubbles. For this second pour I started at around 6:30am and it was cured by 4pm, around 9.5 hours this time probably because it was warmer today with sun shining in through the window. I let this layer go hard past the 'stage B' as it was my final top coat so I didn't need it tacky as I wasn't pouring another layer. In all I used 3 litres of resin to this point and still had a spare litre of GlassCast 50 should I need it for touchups once I de-moulded the top.
All in all this pour had gone well far better than my previous coffee table build pour thanks to lessons learned from doing that. I was pleased with the result as it was sat in the mould and the end of the build was now in sight.
Step 16: De-Mould
With the resin poured I let it cure in the mould for a couple of days so that I was completely set. I then flipped the whole thing over so I could begin to remove it.
With the top flipped I could see a few areas where resin had leaked through, but nothing major, so the next stage was to remove all the screws holding the mould together. Once they were removed I could start prying off all the pieces, the back plates I made to cover the large holes in the oak were the first to come off and the silicone I had ran around the edges had done its job and prevented all my resin flooding under the top and leaking out the bottom. It had a bit of a raised edge but this could be sanded away later so it was flat.
Next I pulled off the side pieces using a screwdriver to get behind the mould strips and pry away from the side of the table. The packing tape I applied to these pieces meant it was easy to pull off and didn't stick to the resin at all.
With all the mould pieces removed it was now just a matter of cleaning up all the left behind silicone sealant. Some of it I was able to just gently pull and it came off clean in one piece mainly, other areas I used a decorators scraper to remove it, scraping along the edges of the top to remove the larger, longer pieces of sealant.
After I'd removed the majority of the larger pieces of silicone the top started to look better, however it would need some final sanding on the bottom to remove the remaining areas of silicone and areas where the resin had leaked through. As the top was still in my dining room I moved it back to the garage to sand as I didn't want to fill my house with dust.
Step 17: Final Sanding & Polishing of Underneath
With the top back in the garage I placed it face down on my workbench, using an old piece of carpet to protect the resin covered top from scratching against the bench. With the bottom of the table top face up I could get to work removing all the final leftover bits of silicone sealant and resin.
Where the resin had leaked through I first used my chisel to scrape and chip away the raised edges and droplets bringing them down flat to the surface. With the higher areas flattened I then used my belt sander with some coarse 40 grit belts to remove all the remaining resin and silicone still left behind. It was just a matter of going back and forth with the sander until all the residue was removed and I was back down to the clean oak surface. Once there I switched to 120 grit belts before going to 240 grit discs on my orbital sander giving the underside of the table top a clean smooth finish.
At this point I decided to change how the legs would attach to the table top, feeling the weight of the top now after carrying it back and forth to the garage I was concerned the screws wouldn't be enough and might tear out, so I added some wood insert nuts instead to bolt the legs to the top.
To begin I widened the pilot holes I'd drilled for the screws to 8mm to accommodate the M6 nut inserts, marking my drill bit with tape so that I drilled to the correct depth. I then used my countersink bit to countersink the holes so the inserts would sit flush one screwed in. Then using a hex bit I screwed the nut inserts in to the holes using my impact driver, stopping when the nuts were flush with the oak surface. Once all the inserts were in it would now just be a matter of positioning the legs and using the accompanying M6 bolts to securely fasten the legs to the table top.
Attaching the legs to make sure they fit, I then removed them again so I could give the underside of the table a coat of danish oil, this would protect and seal the underside as well as give it a nice looking finish (even though you'd never see it). I simply applied the oil using a brush, let it soak in and dry for a few minutes before buffing it off with a rag to a smooth shine.
Now I'd finished the underneath I flipped the top over to the resin coated side to finish that.
Step 18: Finishing the Top
At this stage the top surface of the table wasn't in too bad of a condition from the resin pour. However there were a few blemishes where air bubbles had evaded me during the cure and the edges of the table that were against the sides of the mould had some raised rough edges as well, where the resin had lapped over the sides of the mould.
To get the top looking smooth and flat once more I used a combination of my orbital sander and my random orbit sander together with high grit papers to remove all the blemishes and rough edges. First I used my random orbit sander with 800 grit paper discs in to work along the edges of the table and remove the sharp rough resin that had set there as a result of the pour. I worked up and down the table until the edges were flat and level with the rest of the top. I then focused my attention on where the air bubbles were and using the same sander and paper sanded these areas flat as well. I then went back over these areas using 1000 grit discs to smooth them even further.
I then switched to my orbital sander, initially fitted with 1000 grit wet and dry paper. Using a spray bottle filled with water I then sprayed the top with water to wet the surface before using the sander to go up and down the table top sanding it back to 1000 grit and removing any scratches I missed, left behind from the 800 grit paper. I did the entire top with the 1000 before wiping it down with a cloth, switching to 1200 grit paper in my sander and repeating the whole process again, wetting the table top as I went.
After fully sanding the top with the 1200 grit wet and dry I gave it a good wipe down to make sure the top was dry and clean. Next I then switched back to my random orbit fitted with a large sponge polishing pad this time, I then applied some NW1 Paicristal polish (bough from the same place I got the resin) to the surface of the table and used the sander and sponge pad to work it across the surface evenly, polishing the resin as I went removing any fine scratches left by the 1200 grit paper. After going over the whole top for about 20 minutes, I then applied some finer liquid polish designed for use polishing scratched misted up car headlights. I applied it to the top and using the sponge pad polished it into the surface in the same way, making sure to keep the sander moving at all times. After 10 minutes buffing I gave the top a quick wipe with a rag to remove any residue, the top was now polished and buffed and ready to be put on its legs in the dining room.
Step 19: Attaching the Legs (Part 2)
Now that I had the top finished and polished I needed to re-attach the legs. Before doing so however I first needed to finish those too.
I made the legs 3 years ago, so at this point and they'd been sat in the garage ever since, so naturally over time they had become dirty and had a fairly rough sanded finish. To get them cleaned up I gave both sets of legs a good going over with my random orbit sander, 120 grit first then 240 & 400 grit until the legs were smooth, any dirt and grime removed and the sharp edges rounded off.
I could now finish the legs the same way as I had the base of the table top, with danish oil. Again applying the oil with a brush I painted it all over both sets of legs, before leaving it to dry a few minutes and then buffing off with a cloth. As soon as the oil hit the legs that rich golden colour of the oak popped and the legs looked amazing in the light. With the oil buffed off I left the legs to one side whilst I carried my table top back through into the dining room, its final resting place.
To get the legs back on the top I did the same procedure as I did the first time I attached them, using my saw horses to raise the top up high, before crouching underneath with one set of legs at a time and bolting them on from underneath. Once the top was sat on the saw horses it was just a matter of lining up a bolt in the legs with the nut inserts in the base of the table top. Once I had one lined up the rest of the bolts went in easy enough and with all 4 tightened using a screwdriver on the first set of legs I could move to the other end of the table and repeat the process.
With both sets of legs secured to the top I could then remove a saw horse from one end and rest that side of the table on its own legs. I then lifted the other end of the table and removed the second saw horse, before resting the table down on its other set of legs. The table was now supporting its own weight and the legs felt solid with their heavy top on.
Step 20: Finished!
With the legs attached and the table in the dining room it was finally finished.
This has been a hard slog on this project, I started it 3 years ago so its taken a long time to get to this point, mainly because of other projects coming and going that were more urgent as well as some indecisiveness on my part as a direction to go, resin vs concrete vs neither.
Its finally done though and the dining room doesn't look as bare anymore, just need to get some chairs together now. I have some in the garage that want cleaning up so it'll likely be those.
Overall I very happy with outcome, hope you guys like it too.
Thanks to everyone that read through, its been a big build so there's a lot of steps.
I'll leave you with some shots of the finished thing and a video of its sparkle.
See you next time.
Runner Up in the
Stone Concrete and Cement Contest
3 years ago
Besides the beauty of the table, I really like the level of detail the instructable, especially for the concrete part, that one I needed. Thumbs up, keep up the good work.
Reply 3 years ago
Thanks, I try and get everything I did in there so people can try things themselves if they want. Good luck with your concrete :)
3 years ago
Wow! This is one looong 'ible! You did an awesome job, kudos!
Reply 3 years ago
Haha thanks very much. It does go on a bit, wanted to make sure I’d covered everything.
3 years ago
What a work of love! Well done; it will last decades.
Reply 3 years ago
Thanks, I hope so it felt like a decade getting it finished at points
3 years ago
Absolutely stunning! I’ve seen similar work go for many thousands at my local antiques and craft dealership. This is by far some of the loveliest work I’ve seen on instructables.
Reply 3 years ago
Thanks that's nice of you to say. I'll have to make a truck a load and visit this craft fair.
3 years ago
Beautiful work, that is quite the project!
Reply 3 years ago
Thanks very much :)
3 years ago
That looks great! I love the way the concrete came out :)
Reply 3 years ago
Thanks, for my first furniture concrete pour I’m pretty pleased with it