Introduction: Segmented Bowl
In this Instructable I'm going to be making a wooden segmented bowl using some offcuts of hardwood I have left over from some other projects. I make a lot of bowls on my lathe and so thought it time to actually document how I make one.
The bowl itself is made up of 4 layers, two solid wood and two segmented from a mixture of other woods.
I really enjoy making bowls with different contrasting colours and shapes and hopefully you'll enjoy reading through as well.
Step 1: Equipment & Materials
There isn't really a vast amount of tools required for this build
- Hardwood selection of your choice. In this build I used Purple Heart, Padauk, Ash, Ebony, Walnut and Mahogany but choose what timber you like the look of. You can use softwoods too they just have a higher tendency to tear when you turn them if you're not careful, but also are easier to fix with sanding afterwards.
- Titebond woodglue, again you can use your preference I just find this holds well and its never let me down
- Wax I used clear Briwax to finish this bowl but obviously just use whatever you like the look of
- PVA Glue
- Adjustable chop saw, this is a great piece of kit and allows you to cut at a variety of angles ensuring every cut is the same. You can use a handsaw if you've not got one (I have in the past before the luxury chop saw days) just make sure you're accurate with your marking and cutting use a saw guide if possible.
- Marking equipment, pen/pencil, ruler, compass and protractor.
- Woodturning Lathe, mine is an old second hand record power lathe that I've upgraded with a swivel head kit for turning larger pieces and a simple chuck I bought off eBay, allowing me more flexibility for attaching the pieces.
- Woodturning tools, I have a cheap basic selection most of which came with my lathe. I have added a few more over the years, most recently the bowl gouge which this is my first project using.
- Bandsaw, again this is not essential it just makes it easier to cut out circles and round off corners ready for turning. If you don't have one a handsaw or jigsaw can be used in the same way.
- Table saw, I only used this to cut away large sections of excess timber quickly so you definitely don't need one for this project but if you have one, lucky you.
- Random Orbit Sander, again not a necessity the whole project can be sanded by hand this just speeds up certain processes
- Handheld Drill - used for 4 pilot holes so a bradawl or hammer and nail would work as well
- Clamps - I used a total of 6 clamps but 2 or even 1 large would be adequate depending on the size of your bowl
- Luggage Straps - used to hold the segments whilst gluing
- Varying grits of sandpaper
- Various rags, cloths and towels
Step 2: The Journey Begins, Preparing Your Timber
Once you have selected the timber that you're going to use you need to make sure its flat and even so when it comes to gluing there are no gaps that will show in your finished piece.
Most timber merchants and wood shops will have already pre-planed most timber so it is ready to use straight from purchase. Some of the timber I'm using here originally came from the scrap box at a timber merchant (always check the scrap boxes in these places when buying timber as you can find some absolute gems for next to nothing just as good as the pretty shelf display pieces) and the majority was already planed meaning I had no further work to do on those particular pieces before use.
However if you do need to straighten edges and surfaces there are a variety of different methods available.
One is to use a plane electric or hand the result will be the same, the effort required however will not. I'm lucky enough to have both variants and my electric planer/thicknessing machine is by far the easiest to use, just set the height of the blades and feed the timber through until the desired thickness is achieved and it is flat and level.
The hand plane, again electric or manual requires a bit more work on your part running the blade along the surface until you're happy with the finish. It is easier to make mistakes here and gouge the timber if you're not careful, but plenty of practice and you'll eventually get the hang of it.
You can also use a table saw to get flat edges, the easiest way to do this is use an already squared up piece of timber, such as a plywood board and attach your other timber to this leaving an overhang over one edge of the plywood where you'd like the straight edge on your timber. You can then set your rip fence and run the opposite flat edge of the plywood against this feeding the timber on the other side through the blade cutting parallel with the straight edge on the fence. You can the repeat these steps for the other edges until you've a squared up piece of timber.
Now you've everything square and level its time to mark and cut.
Step 3: Solid Pieces
In my design there are several layers to the bowl and two of these are made from a single piece of timer, One layer is African Padauk and the other Mahogany from an old table top.
To make things easier later and reduce the amount of material I needed to remove on my lathe, I pre-cut these pieces in to circles using my band saw.
For the African Padauk it was rather a large piece for what I needed, so I used my table saw to cut off the excess before using my band saw. This way I can use the offcuts in another project at a later date.
To do this I simply drew a circle using a compass on one surface of my Padauk where the grain looked visually the best, then marked straight lines around the edges of this to mark my cuts on the table saw.
Once marked it was simply a matter of adjusting my saw fence the correct width from the blade and running the wood through until the excess was cut away. I repeated this another 3 times and I could then move over to the band saw and cut the final circle shape.
For the Mahogany layer this would be my base and how I attach the bowl to the lathe so I needed to make sure it was flat and I had the centre marked for when its cut out to its circle shape. To begin I passed it through my planer to remove any cupping and warping that had occurred from its hard life as a table, once it was flat it was a simple matter of drawing two diagonal lines corner to corner, where the lines crossed over was the point to set my compass on and draw the circle, the diagonal lines would be used again later for positioning. I then just went straight for the band saw after marking my circle as there was little excess on this offcut of wood.
Step 4: Marking Up & Cutting Segments
Now its time to mark the cuts for each one of your segments. The angles of your cuts will depend on how many segments you are planning on having.
In my bowl I have made octagon sections consisting of 8 segments each but you can go anything from 5 segments upwards.
The easiest way to calculate what angle each segment will need to be cut at is by using the below formula where n is the number of segments you're planning on using:
=(360/n)/2. For example my bowl was an 8 segment one so 360/8 = 45, 45/2 = 22.5 degrees.
Here are some other angles for different numbers of segments:
5 segments - 36 degrees
6 segments - 30 degrees
7 segments - 25.71 degrees
9 segments - 20 degrees
10 segments - 18 degrees
As you can see the angles may not always be whole numbers and so will be more tricky to cut accurately, for these you may consider making a jig or sled to cut each piece the same and there are many great guides on here explaining how to do so, some of which I'm going to attempt myself!
Now you may notice in the photograph of the purple heart section it has ebony blocks in between the segments, this will make no difference to the angles you need to cut as the ebony is flat and just sits in between each segment which only makes a slightly larger octagon in diameter than without them in between.
To make my ebony blocks I simply used an ebony pen blank (used for making pens on a much smaller lathe) and split it with my bandsaw to the required thickness and length.
Note : If you're unsure of this stage you can always make a template on some paper to help you visualise what you should be doing, this way you wont waste timber by making wrong cuts. Start by drawing a circle the size of the bowl you want then draw lines through it at the centre at the angles you need using the protractor and ruler, you can then cut out the shapes created to use as templates for your timber if you wish.
Right once you have your angles its time to cut the timber. Now you can mark the angles you've calculated on the wood using a protractor and ruler or a template if you made one, so you've marking lines all the way along where you need to cut. Or an easier method if your using a chop/mitre saw is to set the blade at the angle required (22.5 in my case) and cut one end of the timber at this angle.
Next set up a stop block on your saw with the distance away from the blade set at the length you'd like each segment to be. Now take your pre-cut timber, flip it over and place the angled cut end up against the stop block making sure the back edge is flat against your saws fence and make the next cut. Remove the newly cut trapezium shaped piece, flip your wood over again and push up to the stop block before cutting again. Repeat this until you have enough pieces for your whole sections shape, 8 for me.
This cut and flip method is by far the best as it involves no marking of the wood or adjustment of the blade and as long as you keep it flat to the saw all the cuts will be even and should now all fit together to form your polygon.
As in my design you are not limited to one timber per section, I have used Walnut and Ash together in one section but you could use a different timber for each segment its up to you and as the image shows they don't need to be the same size timber to begin with either as the difference in thickness or width can be removed later with a sander, plane or saw or on the lathe making it all uniform when finished.
Step 5: Gluing Up the Segmented Layers
Now you have all your segments cut you'll need a flat surface on which to glue them on as there was no point straightening all that timber to glue them wonky now.
I just used a flat piece of plywood as my base with a piece of plastic sheet laid over the top to stop the segments sticking to it, as the plastic can be more easily removed if it sticks rather than trying to prise away the plywood, baking paper is also an option here.
Apply the Titebond glue to each cut angled side of each segment in your polygon and also glue the faces of any inserts you wish to add in between, such as the ebony details in my purple heart section. Try not to over use the glue otherwise you'll get a lot of waste when clamping up.
Push all the segments together gently so they form your shape (octagon) and the glue starts squeezing out of the joints slightly. To secure the joints I use a simple luggage strap with a clamp buckle. Simply form a loop by feeding the tail end of the strap through the clamp and place the loop around the outer edge of your polygon. With the clamp button pressed so its open pull the tail tight so it pulls your segments together until you've no longer any slack on the tail, release the clamp button and it will firmly hold the strap in place around your segments, wipe away any excess glue that's seeped out using a damp cloth or sponge and allow them to stay in position until the glue dries.
You can also use normal bar / 'F' clamps here, 1 for every 2 segments you have but its very fiddly and you have to try and tighten them all evenly otherwise your polygon shape segments pull unevenly and give an irregular shape. I've used this method a couple of times when I couldn't find my straps and it takes a lot of trial and error as well as patience. I don't recommend this method, unless you like swearing...a lot
Once your segments are pulled together and strapped tight if you wish you can place another flat piece of plywood or similar on the top and weigh it down with something heavy to help keep it flat whilst drying.
Leave the pieces to glue for at least 24 hours before removing the straps. After I removed mine I gave each segmented section a quick sand over with my belt and orbital sanders just to remove any excess glue and flatten out any raises in the timber that may of occurred as a result of been clamped. Be careful if you do sand not to make the surface uneven again as this will result in gaps between your layers when gluing it all together.
Step 6: Gluing the Whole Shabang!
Right now its time to start gluing everything together, its important at this stage to try and get everything glued up as centrally to one another as possible, as when it comes to mounting it on the lathe it will be better balanced and make life much easier and less bangy when removing the initial rough material with your turning chisels.
On this bowl my layers are as follows (from the top down):
Purple Heart and Ebony
Walnut and Ash
To begin I lined up the Walnut and Ash layer on the bottom side of my Purple heart layer by eye and once I was happy the positioning looked central I drew around it so I've guide lines if the pieces did move during gluing. If you look in the photo you can just about see the lines. You can also measure round the edges to get it more accurately centred but I've done this that many times now I'm usually pretty close.
The two solid pieces, the Padauk and the Mahogany are the same diameter so will just sit on top of each other and the walnut and Ash layer is also based on a circle of the same diameter, so lining these three up is a simple matter of stacking them with all the edges as flush to one another as possible.
Now the pieces have been dry fitted together and I'm happy they look central its time to get the glue back out and make it permanent. Laying the pieces in front of me in the correct order I simply spiral the glue round the faces coming into contact with one another then smooth it out so the whole contact surface is covered.
Using my guide lines and my eye (a lot of this is by eye) I assemble the pieces on top of a flat piece of scrap plywood. The plywood allows even pressure to be applied whilst clamping and stops the clamps marking my wood. Another off cut of plywood or OSB in this case is then placed on the top of the assembly and the whole thing is clamped together with as many clamps as I can find / fit, 6 seemed like a good number.
Try and tighten the clamps as evenly as you can initially, 1/4 turn at a time before moving to the next clamp as this well help to reduce the wood sliding around and knock out your centering you did earlier. If you tighten one straight away it pinches the wood on that side and forces the pieces away from one another. If you do get any movement simply release the clamps a little and push the layers back to where they need to be, this is where the guidelines I drew earlier come in handy.
As you tighten it more and more the glue will start seeping out of the joints and run down the assembly, simply wipe this away with a damp cloth. Hopefully as you do you'll not come across any gaps between the layers where they weren't truly flat, if you do you can always fill these later or they might turn out on the lathe.
As you can see in my photo I went a bit overboard on the glue at this stage so there's a fair bit of leakage, but at least I know it'll be stuck once dry, hopefully not to everything else.
Once its all tightened and straight leave it all to dry for at least 24hrs before removing the clamps. Mine was clamped up a week or so due to doing this stage on a Sunday and being back at work the rest of the week ( If only this was my full time job.....one day....)
Step 7: De-clamping and Mounting
Once the glue was dry I removed the clamps and started getting the blank ready for mounting.
To attach the blank to my lathe I used a face plate that attaches in my chuck using a series of metal components as pictured.
- A faceplate ring with 4 countersunk screw holes
- A sprung plate that is forced outward and locks inside the faceplate ring
- A solid metal cone, this sits flat inside the chuck and pushes against the centre of the sprung ring forcing it outwards when the chuck is tightened
- Threaded ring, this secures all the other pieces to the main chuck on the lathe and allows the sprung plate to hold in place
To begin I started by screwing the faceplate's ring to the bottom of my blank in line with the centre. Because I marked my centre position on the piece of timber before I originally cut it out it made this stage much easier.
When the piece was a rectangular shape I drew corner to corner diagonally and where the lines crossed was the centre point for my circle. As my faceplate ring has four screw holes it was simply a matter of placing a hole over each one of these diagonal lines until all four were aligned. I marked their position and drilled a small pilot hole for each one.
At this stage you could glue another piece of sacrificial wood to the base of the blank so the finished piece doesn't have holes in left by the screws from attaching the plate, I chose not to do this and is entirely down to personal preference.
Once the holes were drilled I secured the ring using 15mm brass screws and went to line it up on the lathe.
Upon trying to attach the blank I realised that my bowl was catching the bed of the lathe due to the Purple Heart layers width. To solve this I used a handsaw to cut away the excess timber overhanging on each side of my octagon. My lathe does have a swivel headstock allowing it to be fully rotated to any position and I could of attached it at 90 degrees from the bed where the width of the piece would then not have been an issue. However this was a very heavy piece and due to possible stability and safety issues, cutting away the excess was the better option as I could then use the tailstock for extra stability.
To attach the newly slimmed down blank to the lathe a sprung plate locates inside the metal ring I screwed on earlier, this then has metal plug that pushes against it which forces the jaws of the sprung plate outward into the ring holding it firmly in place. The whole thing is then held on the lathe by a threaded collar that screws onto a chuck already screwed on the headstock. It is then tightened up with a special spanner and the piece is secure.
For added stability I then used my tailstock with a revolving centre inserted, pushed up to the bowl blank and locked off. Unfortunately however due to the depth of my bowl the tailstock didn't extend far enough to make contact with the blank, so to solve this I cut a small round of plywood wide enough to fit inside the bowl which allowed the gap to be made up and let the revolving centre push against it, holding the bowl firmly in place.
A quick spin by hand of the piece allowed me to check that I'd centred everything correctly and there wasn't to much material on one side which would cause vibrations, uneven spin and possibly be dangerous. If this had been the case more material would of had to be cut away or the faceplate removed and re-positioned until centred correctly.
Now the piece was securely and safely on the lathe it was time to make it beautiful.
Step 8: Turning (Outside)
Right Its now time to start cutting away some of this material and get it looking like a bowl.
Fist step is to position the tool rest close to the blank so that it doesn't hit the bowl whilst spinning and allows enough room to hold the tools on.
Once this is done and its secure its time to fire up the lathe. Thankfully upon powering up I had attached everything correctly and I didn't get a lump of wood to the face.
Its now time to start removing material and cutting out the shape of the finished bowl. I have a variety of different turning tools all designed for different purposes and cuts but to be honest I just use the tools that work for me to remove the material that I want. At this early stage I chose a wide bowl gouge to remove the material down until all the flat faces are removed and the blank is completely cylindrical.
Start by resting the gouge on the tool rest and slowly introduce it to the work until it makes contact and starts cutting. Move up and down horizontally along the tool rest at an even pace to cut away material along the length of the bowl. Keep moving the gouge inward toward the bowl after each pass to cut away more material. Depending on the materials used in the bowl some will be a lot harder to cut than others, here it was the purple heart and ebony layer that took the most effort to shape.
On this layer I switched to a smaller sized spindle gouge as it applies more pressure with it being a narrower cutting surface. However because of this you need to be more carful as its much easier to make it bite in to the wood throwing the tool back out and causing damage to the work.
The main result of this damage is usually tear out where the tool rips across the wood and leaves a large scar or rough gouge in the grain of the wood. At early stages this isn't a major problem as you can simply turn it out again using the tool. Later on however if you're close to final depths or finishes its a better idea to use sandpaper of increasing grits until the scar is removed rather than risk further tool damage or tooling marks.
Once the blank is roughed out you can now use the shaping tools to cut away the material in the same way to produce your final outside shape. I used a combination of tools in the images to produce my shape, its just a matter of applying pressure in the right areas with the tool and moving it as evenly as possible across the rest and work to produce the curves and lines you want. Once the outside of the bowl is finished we can move on to cutting the inside.
Step 9: Turning (Inside)
To cut the inside of the bowl first the tool rest will need relocating to allow you to get the tools positioned correctly over the face of the work.
To begin I normally start with the rest positioned parallel to the face of the work and use the tools to cut along the left hand side face and inside of the bowl. You always want to cut on the left side (as you're facing the bowl) so that the rotation of the piece is heading down towards the top of your tool (anti-clockwise) and not up like it would be if I were trying to cut on the right hand side of the bowl. This is because the tools cutting surface only works from the top down and the tool has the possibility of being thrown out of the work if working with the rotation hitting the bottom of your tool first.
Again the tools used are entirely dependant on what you feel works best. I normally start with the gouge to rough it out and get any flat edges inside round and the face flat and level before moving onto other finer cutting tools, such as my curved neck bowl gouge, which allows easier access to the inside walls of the bowl.
Another tool useful for removing material initially is the parting tool which can be plunged into the timber and worked along the face of the bowl to remove excess quickly and get the rough shape you want. Alternatively you can use a large diameter drill bit such as a spade or forstner bit in a chuck located in the tailstock to drill out material to the required depth, before using the chisels and woodworking tools to finish it off. This is a good method if you've a solid bowl like the bottom two layers of mine and you want to get the material out quickly.
Since the top two layers of mine were just rings on this occasion I just used my gouges and parting tool to remove the excess.
Once the internal shape was cylindrical and all flat edges from the octagons had been removed, I could re-position my tool rest once more to inside the bowl allowing me to cut closer to the wood and have more control over the tools. I now used my other finer detailing chisels such as my round nosed, curved armed gouge and 45 degree flat edged to remove smaller amounts of material and remove any tooling marks and tear outs from the earlier roughing out.
Once I'd got down to the depth and shape I was happy with I could stop the lathe and inspect the inside to make sure everything was as I wanted.
Cutting the inside of the bowl to me is the hardest part as it often requires you to be stood in an awkward position and you cant always easily get the tools in where you want them, but if you persist and adjust yourself accordingly you can eventually get the cuts you need and finish the inside.
Step 10: Sanding Then Some More Sanding, Followed By..... Yes More Sanding.
Now that I had my final shape of my bowl, it was all pretty rough looking with some tear outs tool marks and generally rough edges that all needed dealing with.
The best way to do this is to sand it all back so that you get a nice smooth even surface ready for finishing.
There's no quick and easy way to do this, its sanding everyone knows the drill its the same for whatever you're building, just start with a course grade of paper and work your way up to a fine grade. Again here the hardness of the timbers selected will influence the time it takes to sand them back, the Purple Heart again caused me the greatest issues due to the time, especially using the finer papers as the paper would clog more easily with dust removed from the wood and it would remove the fine grit from the paper quicker resulting in more sheets being used.
A few tips I have for sanding the bowl are:
- If possible use sand paper designed for belt sanders or other power tools as these are usually more heavy duty so will last longer and cut better due to normally having to stand up to much more heavy duty tasks such as sanding floors. An 80 grit belt worked wonders for me on this project to remove tear outs and tool marks quickly.
- Wrap your sandpaper around a block or sponge, a shaft anything really, this makes it easier to apply pressure and get into any tighter spaces you may have such as the inside curve of the bowl. I used a small sponge that shaped nicely to match the inner curve whilst giving me something better to hold and allow pressure to be applied evenly without the risk of burning my hands on the spinning timber.
- Cut and fold sandpaper so that it better fits the shapes you're trying to sand. Its no good struggling with a rectangular ended piece of paper when trying to sand a rounded profile or curve, as this increases the risk that one corner of the paper could catch your work and tear out a small chunk resulting in more material having to be removed and even more sanding having to be done.... not more sanding please.
Eventually as you work your way up the grits the surface of the wood will get smoother and smoother and begin to shine as the finer papers start to polish it. This is when the bowl starts to come to life and all that horrendous, laborious sanding and been covered in dust for hours pays off and we're nearly there.
Step 11: Polishing and Removal
Now that its sanded back to within an inch of its life its time to bring out the colours and grain of the woods.
Its first a good idea just to give the bowl a brush and a wipe down to remove any dust and dirt on the surface before you apply a finish. My finish of choice on a bowl like this is a clear beeswax, usually Briwax as its easy to apply and gives a nice finish.
Using a brush, rag your hand, apply the wax on to the bowl coating it evenly all over making sure to work it into all the grain and any features you may have such as small cracks or knots. I normally do this with the lathe turned off rotating the bowl by hand so I can better see places I may of missed.
Once its all coated leave to dry for a few minutes before starting the lathe back up and using a cloth to remove the excess wax, polish the bowl to a shine. You can also use fine grade steel wool or some wood shavings to polish the bowl.
After all the wax has been polished re-apply another coat in the same way and repeat the process until you're happy with the number of coats and finish of the bowl.
To remove the bowl its just a reversal of how I attached it. Before I start removal I like to place a towel or something else soft underneath it just in case it slips or falls to prevent any damage to it from hitting the sled.
The first step is using the spanner to remove the threaded collar holding the bowl in place, once this is loose the bowl complete with face plate can be removed and placed upside down on the bench, again on top of a towel to prevent scratching. The 4 screws securing the plate to the bowl can then be unscrewed and the plate removed to reveal the base of the bowl with 4 holes in some pencil lines and an un-waxed area.
Step 12: Final Finishing
With the bowl finally off the lathe its time to finish it off.
On this project I screwed directly in to the base of the bowl so now I've four holes leftover. To fill these I mix up a paste using PVA glue and some of the shavings from turning the bowl of the same colour as the base.
I apply the paste to the holes and leave it to dry over night, Once dry using my random orbit sander I remove the excess paste and any other pencil marks and blemishes on the bottom using a course grit paper. After the heavy debris is removed I change to finer paper for the finish.
I then sign my initials on the base as I do with all my bowls and apply some more of the wax to the newly sanded area and leave it to dry a few minutes. I then use a combination of a rag and a cone shaped polisher in my cordless drill to polish the wax and get a finish to match the rest of the bowl I achieved on the lathe using a few coats of the wax in between polishes like before.
Leave the whole thing to dry a few minutes and its done!
Step 13: Peacocking Photos
Here are a few images of the finished bowl, really pleased with how it turned out and hopefully you guys enjoyed reading about it. See you soon on something else