Introduction: Oak Beam Dinner Table
This instructable shows the step for building a table made out of wooden beams.
I did everything in my 3x6 (meters) garage. I just started some woodworking so I don't own the proper equipment for every job (yet). So I had to be creative a number of times.
- 5 beams
- 3 stainless steel rods and the following materials (all stainless):
- 12 big washers as separators for the beams
- 6 washers for the pockets of the nuts
- 6 end nuts
- 6 springs
- Belt sander
- Circular sander (or a similar small sander)
- Mitter saw or a track saw
- Measurement tape, level, carpenters square, pencil,
- Putty knife
Step 1: Selecting Products
Finding the proper wood is a challenge. Beams are not cheap, and the price reflects the quality of the wood (bad spots) and also how dry the wood is. It can take decades for for large pieces of wood to air-dry.
Sometime you can get the price down using the following options:
- buy the smallest piece you can use (so minimize waist), these are also likely more dry
- use air dried wood (so save on drying chambers)
- buy the smallest piece you can use (so minimize waist), these are also likely more dry
After deciding on the sizes for the beam we found out the table top would be over 150kg! I decided to go with iron legs to support the weight. This made it also easier to attach and I like the design. I used a cheap iron tube because it's cheap and easy to proces. I used the Geometry Solver app for Android to calculate al the different angles. So it was easy to get a good construction drawing using this. I had help from my brother to make the legs
The one in the back (second from the top) was our pick. It was 5 meters long and 200x200 mm. Which is a more expensive size. It was to little wood for our table, so we picked a smaller beam as our fifth (hoping there will be little difference in color). An important downside is that 200*200 downside is that they should be cut using the bandsaw. Even after nine years of air-drying the inside was still relatively moist compared to the outside. Its important to keep the insides on top. As wood dries it gets more 'compact' and this way it will even out more nicely.
I decided to cut the beams on length myself. They were very raw and I wanted to see the texture to decide what would make the prettiest ends.
Step 2: Sanding, Sanding, Sanding, Sanding....
Decide on the layout
After inspection at home I decided to use the one beam that came from a different tree as the middle one (it differs slightly), to keep the table top mirrored. The others will have a 'random' order. The beams had been laying in (protected from rain) outside for nine years, so the wood was quite raw.
I was on a tight budget, so I decided to sand the raw beams. However a thicknessing machine would will save you thens of hours of sanding. In the end I saved $80 dollar by sanding 40 hours, so this was not the most efficient spending of my time, however very therapeutic!
I decided to use a belt sander (Makita 9903) to get the beams in shape. I used 40 grit belts for this.
Using three different sizes levels (or something else which is really straight), I was able to make some corrections so the beams became straight enough (remember, the design didn't require them to be perfectly paralel).
There where som bumps and bruises in the beams and I used a circular sander and some chisels to get them out. Offcourse I also sanded quite a lot by hand.
In the end, this job took me about 4 hours for each beam. In the end, they were reasonably straight, and ready for sander finishing (140 grit). But that's a different step.
Step 3: Filling the Seams (optional)
Dried wood usually has cracks, bruzes and seams. Using the top side up I used my hands to discover bad spots. There were some places you could feel the wood bending when applying pressure. I wanted to give the wood more support on these spots by using a filler.
Make the filler yourself
By mixing saw dust (lots of that in your belt sander) with glue (just regular glue for wood) by using a couple of two putty knifes and mix it up. It is not the easiest thing to mix. My consistency was close to the bondo u buy at the diy store.
I used a putty knife to put the filler in. Some seams are small, so I used a nail to get the filler in more deeper.
After a day the excess can be sanded of.
Step 4: Cutting the Beams on Length
Now the beams are sanded, it is easier to see the 'picture' of the wood, so you can decide how long the table will be and what would be the best place to make the cut.
Use a mitter saw
If you have a mitter sam, this would be the easiest. However most mitter saws have a maximum of about 7 or 8 centimeters of wood. The beams are likely to thick for your mitter saw.
If you have one that's good for the job, use a carpenters square and a pencil to draw a guide line for your saw. However beams are not always straight (unless you used a thickenessing machine), so the square could be a little bit off.
Use a track saw
I used my Festool TS 55 Tracksaw and clamps. I had to saw it (55mm in depth) and turn the beam around to do the other side. I used a carpenters square to mark the endings around the beam. This is a good test! As you work around the beam, you will end up at the same place (when it's straight) or - in my case - the lines where off 3 mm. This is the point where you begin trusting your eyes. Afterwards I used a belt sander to even out the inventible saw lines. And used the circular sander to make it more smooth.
Step 5: Drilling Holes
There are a couple of options to drill the holes. The rods I used are 10mm standard RVS threaded rods (1 meter length). We decided to drill 12 mm holes so we have a little room for configuration corrections(meaning error).
Large pockets first
Start with creating the larger pockets first. Decide on your nuts for the rods first For the outside beams, a special big hole was made using speed drills, because this is were our nuts wil be. Using a mandrel we guided the drill and made a 38 mm deep hole. We made it 32 mm wide, but just make sure you can fit your wrench in it to tighten the nuts.
Use a horizontal drill table
This is probably the best option. The beams are heavy so a horizontal drill make positioning the easiest.
Use a vertical drill press
This is an option, however the beams weigh about 35 kgs each! So they were quite difficult to handle. You can use a level to keep it straight. However, the one I had access to did not have enough clearing to handle the 200 mm beams + the drill (285 total length).
Use a drilling guider
U can use a drill guider (see picture). However I don't have one, and good ones are above $50.
Make a drilling guide
Find something hard and sturdy. Metal or hardwood are both fine.
We made a drill guider using a 25 kg block of metal from an old crane counter balance. We drilled 12 mm straight holes in it using the drill press. We attached the blocks using big clamps. Drilling is done using a standard power drill. I had help from two people telling me how straight the drill was (just for additional guidance).
It's important to pay attention to the friction between the drill and the guidance. In our case we sprayed the drill with drill lubricant. However, watch out you do not spill it over the beams, the grease will probably stain the wood indefinitely. So spray far away from your beams, and afterwards, start drilling. Also move the drill up and down quite a lot. Wood chips from drilling will create more friction as well.
Surprisingly the drilling part went quite well. The holes were within 2 mm error-margin.
A first test
So I decided to use the rods the first time to connect the beams and see what the end-product will be like. Using a level I made a few corrections, however thanks to the 'error margin' vertical corrections up to 1 (sometimes 2) mm can be made in the end. Also, the product was designed to be a natural looking not-so-perfect table. So this also left me some margin for error. I am really really really happy with the drilling results!
When the holes are to far off, you can try to use a router to make the hole somewhat bigger, however most bits are to short to get in really deep. Start with a centimeter and adjust the depth in small steps.
Step 6: Preparation for the Legs
After a quick 'fit' I decided to use a router to sink them 5 mm. So they definitely can't hurt any knees, kids and chairs.
Step 7: Finishing
Finish the table by sand the beams using 140 grit paper. I softened the edges quite a bit. Especially on the ends of the beams. This make the beams come out a little bit more, because spacing in between increases a bit.
I used Ciranova Aquafix Matt finish. It had already used it for the kitchen (also heavy duty use). So I knew how it colored the wood. It is easy to use (dry in 30 minutes and repaint in two hours). Sand between paints.
I spray painted the legs with a matt transparent coating three layers.
U used trestles to lay the beams on. I fitted the rots. Measure diagonally over the table top to get it straight. Both diagonal lines should be equally in length. Use a wrench to tighthen the nuts of the rods to get the table top square. I used little rod springs on the rods to cope with expansion of the wood. This will also keep the nuts more tight under vibrations. I used washers between the beams to keep space in between.
We lifted the table up with four people and placed it on it's metal legs. I attached the legs using 12 screws for each leg. Use heavy stainless crews for this as the pressure when sliding the table over the floor is quite big for tables of this weight!
Overall we are very happy with our table. Overal it took two months of work (evenings and weekends). Most of the work was in the sanding. The best part is that your dinner will taste even better on your home-made table!