Finished bowl, using inlay, segmentation and a floating base which allows wood movement without placing any stresses on the piece.
Skills needed:
Intermediate scroll saw and intermediate wood lathe.
Tools needed:
Band saw, to cut 3/32" veneer pieces for inlay.
Scroll saw with 28 TPI blades to cut inlay.
Wood Lathe
Accurate miter saw, or miter gauge on a table saw.
Lots of clamps
1/32" drill bit and drillling machine.
Materials needed:
Wood from your scrap pile, I have a golden rule not to use workable lumber for my turnings.
We start off with the inlays, decide the size of your base and select two boards for cutting 3/32" veneer, use two contrasting colors. Bowls are like ladies, small bottoms look great. I used Padauk and Yelloheart.
Use double sided tape and sticky on one of the boards. I use carpet tape from Lowes, the less you use, the better, I actually used too long strips here, which made it difficult to take things apart once done.
You are now ready to stick the top board which will carry your main inlay and drawing onto the bottom board. Again use double sided tape to stick the pattern to the top board, cover the entire bottom of the pattern with the tape, covering the whole area and then stick it on the top board.
We will now do angled stack cutting on the scroll saw, so that the inlays fit exactly. You can tilt your scroll saw table to the left, or right, it will just change your cutting direction. Use a fine 28 pitch scroll saw blade and drill a hole for your entry point to cut the inlay. Use a small 1/32" drill bit. For this piece I tilted the table to the left, between 6 and 7 degrees. That means if I cut clockwise around a shape, the top board cut-out will fit exactly into the bottom board and if I cut counter-clockwise I will inlay the bottom cut-out into the top board. To make sure I have the angle right and to fine tune the angle, first use a scrap piece or cut in an area which will be discarded. The picture shows left tilt, with pilot hole on a corner which will be discarded, to make a test cut.
This picture shows the test cut, which is OK at my angle of 6 degrees. Adjust your angle so the after the inlay cut the piece being inlaid is ever so slightly past flush, or in other words sunk slightly deeper than flush, as this makes it much easier to remove the bottom scrap piece when using delicate patterns. If you don't do this, when removing the bottom cut-out, to make place for fitting the top cut-out, the bottom piece will get stuck just before it clears. With thin lines and delicate pieces this complicates things. The picture shows a test cut, clockwise around a circle to lay the top Padauk into the bottom Yelloheart and the picture is taken from the bottom. It shows a scrap area of the board, with the pilot entry hole and a perfect fit. We are now ready to start our inlay.
The black parts of the drawing will be Padauk laid in top to bottom into the Yelloheart (Clockwise cuts). The light parts will be Yelloheart laid into the Padauk, bottom to top. (Counter-clockwise cuts) We start with the latter for a very good reason, being that they are not fragile, so we can remove them from the boards for later placement without the risk of breaking them. Drill all the pilot holes in places where they can later be filled, so they are hard to notice. Tape the clearance plate of your scroll saw, to make it a zero clearance plate, otherwise these small pieces will fall into the scroll saw and magically disappear as the reciprocating blade holder launches them to some mysterious destination.
The picture below, shows all the counter-clockwise cuts, with the pieces marked and stacked to the right, being Yelloheart that will be inlaid and glued into the Padauk.
Use glue and a pointed stick to push the pieces home. Use the glue very sparingly, covering only the edges as the last thing we want is the two boards stuck together when it is time to pull them apart. That will destroy the piece.
The picture below shows each Yellowhear piece, pushed from the bottom into the Padauk board or in other words inlaid into the Padauk board.
Same picture below, as the one above, but taken from the other side, showing the little pieces inlaid and now we are ready to cut clockwise the remainder of the outer pattern.
The entire pattern has now been cut and the picture is taken from the bottom. These tips are very important, not following them will make one learn the hard way. Keep this Padauk shape inside the two boards, and remove the Yelloheart. If one tries to remove the Padauk, all the fragile lines will break and the project will fail. From the underside sparingly glue all the Yelloheart edges, turn the board over and pust the Padauk piece into the Yelloheart carefully, completing the inlay process.
Before the glue sets, take the two boards apart, so we are now only left with the inlay and we can further push the inlay nice and flush. Shown below.
Our inlay process is now complete, so we can start with the bowl. First thing is to glue the inlaid veneer board to its substrate, which will be the bottom or base of our bowl. I basically just use TB glue and clamp with a piece of foam pushing the veneer uniformly against the board. The picture below shows the base board, bottom up (veneered inlay sits underneath) and next we draw two circles, the outer for cutting the round base and the inner for gluing a tenon on the back of the base (bowl bottom), so we can mount it on the lathe. I use a chuck, you can also do this with a face-plate.
The next picture below, shows the base cut on the outer circle and the tenon being glued in the inner drawn circle.
We are done with the base, or bowl bottom with it's inlay. Next is to start cutting the bowl segments. Start with sticks which are planed to exactly the same thickness and the width you will need for your segments, as below.
My segments will be 30 degree segments (pie pieces), meaning the miter saw will be set at 15 degrees. To find the exact size of the segments, draw a circle as below, with the outer diameter slightly larger than what the bowl circumference will be. Then use a protractor and draw a 30 degree segment (pie) into the circle. From this we can scale each segment exactly, by marking the inner and outer rings of the segmented ring we wish to make.
Next, calibrate the miter saw to be dead on, this is very important. Not all squares are not necessarily square, make sure this is dead on. I use a sacrificial fence for two reasons, being that my Dewald is not accurate enough and secondly it helps the smaller pieces when cut, not to become missiles.
Next, I set my miter saw into its 15 degree notch and I set a stop which has been cut at 15 degrees to give me the right segment length, for the first ring.
We cut twelve segments.
The twelve segments are glued by gluing the edges, rubbing together, placed on a piece of wax or parchment paper and clamped tight with a band clamp. The ring needs to be pushed flat. Personally, I prefer parchment paper, as I can draw and write on it.
Our first segmented ring is now glued onto a sacrificial face-plate, for the latter I used a piece of ply.
We mount the sacrificial face-plate on the lathe and turn a rabbet to fit the base. The base will be glued with correct grain orientation to ONLY TWO segments, so it is free to expand and contract across the grain. Failing this, the bowl will warp, or even crack.
We cut the rabbet slightly deeper, so we can flatten the segmented ring with a skew, or gouge to get the whole surface flush. We can now size our next segment, for our keeper ring.
Everything turned nice and flush, note we have a little more than 1/16" gap between the ring and the rabbet edge, allowing the base to float and also allowing any possible extra glue to rather go into the void than stick onto the keeper ring.
Use glue sparingly, keeping it away from the floating base and glue the next segmented ring.
We are now ready to turn the bottom of the whole bowl.
Once the base is turned, we are ready to use a parting tool and cut the sacrificial face-plate off the bowl.
We can now grip the piece on the tenon, below the base, glue our next segments up and complete the turning. To remove the sacrificial tenon, I use a jam chuck, some have nicer toys. That ends our tutorial, post questions if you have, or better ways to do this will also be welcome.
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