Restoring bowl dovetails

I would be interested in a jig to do that on the router. I would think that would be quicker than having to redo the jaws on my chuck.

Tim

I would be interested in a jig to do that on the router. I would think that would be quicker than having to redo the jaws on my chuck.

Tim

It seems to me that the lathe is the right tool to true up the dovetail

-- not a router.

Make a small jam chuck -- maybe 3 or so inches in diameter. Your blank should also have the hole caused by your tail center visible; that will make centering it easier but is not completely necessary.

Mount it between the jam chuck and the tail stock, top of the bowl to the headstock side and then cleaning up the dovetail is a piece of cake. If it is small then you might need to make a small special cutter to get to it but I'd say this is the way to go.

Bill

tdup2 wrote:

Have you ever considered using a pin chuck for roughing and leaving the pillar intact in the drying bowl? Makes an easy recenter because the hole remains full size in the direction of the grain, guiding the bit to center and removing the face grain symmetrically.

Additional benefit in that you can re-turn the outside and bottom to circular toward the headstock with no interference. It can also provide you with support by snugging the tailstock up after re-chucking in the dovetail, allowing a faster hogging rate as you turn the interior for thickness and circularity. Protects the turning from an accidental dismount until it's at its lightest and best balance, too. Pictures of the procedure, using both pin chuck and pin jaws at

for your examination. 14 degree bit, easily obtainable, will work as well. At a quarter inch depth the degree difference is certainly within the elastic limit of the wood.

Anything on three points will sit steady. With an adjustable point, should be able to regain parallel with the original bottom.

Thanks! I do use a pin chuck and leave the pillar until the last thing while roughing. Never thought about leaving it until finish turning. Shows my age. The 15 degree bit was easy to find, but only in 1/4 shaft.

Here it is.

Making the jig. Two pieces of 1/4 masonite 1 ft square. Base of scrap

3/4 wood 1 ft. square. Drilled 1/4" pilot hole in center of both pieces of masonite. Cut 1 1/4" hole in one with hole saw, 5" in second piece with fly cutter on drill press. Glued pieces of masonite together. Cut corners in top & bottom pieces to hold rubber bands. The bottom piece of masonite is just a stiffener and the 5" hole gives clearance for bowl bottom.

Used 15 deg. dovetail bit in router with a 5/8 guide bushing.

procedure. Sand bottom of bowl flat and top fairly flat on 4" belt sander. Invert bowl on base of jig, center masonite guide on dovetail recess of bowl and hold with rubber bands on corners. Adjust depth of bit to touch bottom of dovetail recess and route slowly letting guide bushing guide the router. A soft start router and slowest speed is the way to go. I stop frequently and blow the dust out so it won't interfere with the guide bushing.

Pictures in ABPW. This is only a prototype to see if it was feasible. It has worked well for me for the few weeks I have used it. The masonite is a little flexible and a better clamping method would probably help.

I like George's method of leaving the center pillar, but I have a pile of drying bowls that do not have it so for those that warp, it is this or the cole jaws and they do not work so well if the rim is also warped.

Seems you could use a bottoming bit, the same jig and bushing for level rather than fussing with sanding? Then go two steps up in the bushing and work your dovetail. With the longer shanks on 1/2" bits, you could easily go to 1/2 stock and avoid the flex.

I'd wedge for level and tack with hot glue for down below.

You lost me. How can I level the bottom if the jig is resting on it? The dovetail bit does cut on the bottom, and levels the bottom of the recess. On the bowls I've done with it, it takes about 2 seconds to knock the bottom flat on the sander. It does not seem necessary to level the top of the bowl.

Rest the jig on the table or whatever via the three legs straddling the bowl. I hate belt sanders, gave mine to the school after rounding over and gouging everything I touched with it. Now a block plane....

This whole discussion seems to me to elucidate a lot of hard ways to solve an easy problem. The lathe is the right tool for the job.

Bill

George wrote:

Have you ever actually done this?

On every bowl I do. The only difference is that I use a tenon instead of a dovetail -- much more secure in my opinion. If I used a dovetail I'd need a small tool to get in given the interference of the tailstock. This is another justification for using a tenon instead of a dovetail. It would make no difference in the finished product because I'd get rid of either.

Bill

Gerald Ross wrote:

I agree with Bill, I use a tenon instead of a recess. Many years ago, I sometimes used a recess until a fellow brought in a bowl to the club meeting that was split in half because he had tightened his chuck too much using a recess. After that, I never again used a recess only a tenon.

When re-turning a rough turned bowl, I open my chuck jaws quite a bit and place the inside of the bowl over the chuck. I then bring up the tailstock with a live center and clean up the dovetail on the tenon. Because I always start my bowls originally between the face of the jaws of the chuck and a live center to turn the original tenon and the outside of the bowl, I have a center point for remounting after the rough turned bowl has dried. I keep this center point all of the way through until the final turning of the foot on a jam fit chuck or a vacuum chuck.

Fred Holder

Looks like a good idea, if I could find a router under all the bowls and shavings.. lol

Personally, I'd rather do it on the lathe, feeling that the end really would be true to the bottom... I'd be sort of afraid that your new or cleaned up recess might not be the center of a warped bowl any more, and the bowl would really spin awkwardly..

I find that it's pretty fast using a jam or vacuum chuck and the live center without the point... holds the bowl and is adjustable for allowance of warp and lets you do a little truing and cleanup while you're at it.. YMWV Mac

Ok, Reed... let's assume that you mean "re-turn".. lol

My concern on a warped bowl, and I think that was the motivation for using this jig, would be the TOP of the bowl more than the actual recess..

One of the reasons that I went to a vacuum system was that when a bowl is nicely warped, it won't sit flush in a cole/jumbo jaw setup... which makes it hard to hold and harder to do anything to the bottom of the bowl..

Mac

Gerald... I'd rather ask a dumb question that make a dumber mistake, so I'll ask what kind of chuck you use?

My guess is a Nova? The Oneway series would require a straight bit, I think? Mac