MIMF

Hi, I'll probably joint some pieces for plates this weekend, and as usual I was planning to place the matching faces inwards and then joint both pieces simultaneously (maybe with the trusty No. 6 foreplane?). As is well-known, this maneuver compensates for an off-square planing stroke. But I got to thinking. If the matched plates were planed for jointing at a 45 degree angle, this would create a greater surface area for glue (@45deg: = plate thickness x 1.414 (x length)). But would this be of any practical value? I suppose that it might be difficult to get a perfect visual bookmatch or aesthetics, and so a center strip on the seam might be considered.

The bigger issues is that when you remove even a slight amount of material when leveling the bindings and during final sanding, the joint will no longer be perfectly straight, nor will it be perfectly centered.

Not to mention the fact that you're looking to fix a non-issue... <g>

...and the pieces would probably tend to slip apart when clamped

I should add that even a makeshift shooting board should make for a pretty close to square edge...

Thanks, it was just a thought. I didn't think of the off-center issue that would occur after binding & final leveling, etc.

But I use a shooting board, btw. It makes life much easier.

You could increase the gluing area by using a half lap joint and retain a straight and centered joint, and if carefully done keep things visually bookmatched. But it would add complexity to making the joint. The simple expedient of adding the cross grain strip on a butt joint (which many of us do) might even give more strength with less work.

Micro-biscuits....

;o)

There's a builder named Howard Klepper I believe that puts together plates (of different species nonetheless) using dovetails.... It's a pretty cool look, but a lot of worK!

Howard used to post on this forum. "Dovetail Madness" was one of his art guitars and I'm not sure if it was veneer overlaid on solid wood or solid wood dovetailed together, but it is not how he regularly builds guitars. He has done a number of other interesting art guitars but his more conventional stuff is just as nice.
I believe he doesn't use the reinforcement strip on the center seam of the back, which some builders don't feel is necessary. Being a "belt and suspenders" kind of guy, I still do.

On My first guitar in 1999 i added a george nakashima dovetail just because i liked his work and thought it would add strength, and shared your concern as the glue surface is so small (about 2 sq in).
Subsequently i had a mahogany back that needed to be reglued (it was not level) and instead of ripping it apart i carelessly figured i could snap it in half. I was using titbond and the joint didn't fail, the mahogany cracked luckily very close to the joint.
I never worried about this joint since, i have a jointer and do both pieces together, my clamping is only "finger" tight.
50% of my guitars dont have a center strip and that percentage is increasing.
Ive now switched to gorilla wood glue, i tested it and like that it dries clear rather than white.

Howard's wasn't actually dovetailed.... The "dovetails" were actually inlaid to appear like the plates were dovetailed. Pretty neat trick, none the less.

I've actually seen a few pics of his "normal" guitars... It probably wouldn't be practical to do anyway since it would be all short grain. But, if they were half-lap dovetails, that would be even cooler...

It's a small detail of a backplate that likely has nothing to do with the overall quality of the craftsmanship, but when I look at a guitar, I look to see if the backplate has been carefully aligned for a most-perfectly-possible bookmatch.

About Howard Klepper, well, the visuals of his works are very impressive, and yet I wonder if they were demonstrations of CNC work. I'm not dissing Howard or CNC craftsmanship, but I'd say that he showed excellent work but he didn't share much and explain about how it was done.

I viewed some pictures of Howard's third dovetail madness guitar posted to the AGF some time ago. The plates appear to in fact be dovetailed together. They look to me to be cut with a dovetailing jig because they are so uniform in size,. To me it is the idea rather than the method of execution that is important to the work. Art for art's sake?

It was Howard himself who told us they were inlaid to make the plates -appear- to have been dovetailed.

I recall that he said that too. It makes since to do it that way as the short grain across the narrow throat of the dovetail would negate the benefits of true dovetails.

It doesn't seem like the most difficult thing to do and make it somewhat strong. You could cut the rabbet in one piece and then the tails, then use said piece to mark matching pockets in the other piece... Maybe time-consuming, but you would in essense be "inlaying" one side to the other... It could even be done half-and-half, where the two parts would interlock ike a "zipper..." Not saying this is the way He did it, but maybe the way I might attempt to do it if I had to.

Could also easily be cut with a laser as well... though that would cause the aforementioned problem with short grain. A wider center reinforcement strip would help....

Perhaps Howard changed his technique for dovetail madness 3. If you google AGF dovetail madness a thread comes up that has some pictures of the guitar under construction. The dovetails appear to be integral to the pieces. He does mention they lack strength until backed up.

Alan Carruth wrote:Micro-biscuits....

;o)

That would be Nano-biscuits.