Official Luthiers Forum!

Yep, that's what I meant. Can it be done and still keep the sides *relatively normal* thickness and weight overall?

Dennis

_________________
Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

You guys doing laminated sides: Are you doing your own resawing and cutting your sides thinner right off the bat, or are you thinning down sides of a "normal" thickness from suppliers, or are you purchasing thinner sides, or what?

_________________
Mike

"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Shoosh." The Stranger

But, she told me she was "Amanda." Oh, wait a cotton pickin' minute! Maybe he was saying "I am a man, DUH!"

Sure could pirouette though. But I digress...

So, you're saying I'll need 3-ply, with titanium as the middle ply?

Dennis

_________________
Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Well, maybe fifty-four ply. Using maple veneer, I'd guess that when you had enough layers built up to prevent deflection when the ribs were on an end block, you could dispense with the lining. I've seen this (well, fewer than 54) on thinline AE s, where the plates were glued right to the thick sides. I'd sure hate to have to hand-sand a stack like that on a dish or flat plate.

Dan

_________________
Dan
http://www.acme-archtops.com

Actually for the 2 builds I did with laminated sides I used laminated solid linings (5 x .045" strips of mahogany/bloodwood and mahogany/spruce). Doesn't get stiffer than that… It's a lot of work though, as I had to build the forms to laminate the linings, and gluing solid linings onto compound curves is a struggle. Again those are spec guitars.
After all this, I'm not sure it's worth the time and effort. I'm well advanced on a 2nd build with side doublers and kerfed linings, and I think I settled on this method for now. As part of the system I tend to brace my backs on the heavy side, and cap the braces and graft with a hardwood laminate.


Veneer is widely available in roughly .023" and .040" thicknesses. I resaw mine when I can, or when I want specific tonewoods. The outer layer is just a side set taken thinner than the usual .070"/.085" range.

_________________
Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I think to best withstand the forces of weight on the neck block when standing upright a brace running across the waist would be best. That and no flat point at the neck joint area. I have put a cinder block on the rims with very little deflection after installing solid linings to double sides just to see if I could. Most of that movement was at the waist.

For solid linings, I have been utilizing the double side glue-up procedure. I bend 3 sides of spanish cedar at about .085-.09 and glue those 3 together over the 2 double sides. They all lock together and then I use that 3 ply cedar lining sandwich as the caul for the second pair of double sides. Once that is done I rip 4 pieces off of the sandwich for perfect fitting and ultra stiff linings. You have to rip them well oversize to account for the taper and then sand in the correct shape. A 4 1/2" side will take care of most styles. I built a jig too to rout in perfectly tight side braces that extend all the way through the linings with no gaps. It has worked very well so far and is so quick and easy to install, it is already perfectly mated to the side as they were created (glued up) together. It assumes your double side jig registers against the outside of the side though, not the inside. It removes having to offset anything, you can use any lay up you want.

_________________
Burton
http://www.legeytinstruments.com
Brookline, MA.

Todd,

All of the reverse kerf linings I have seen are rectangular up to the cap where it is then rounded over. With the solid linings, you can put a very steep traingular profile into them. That does a lot to offset the loss in mass by kerfing the reverse kerf linings. Not that it matters too much, it is such a small amount of mass. I do notice a much larger difference in stiffness between them though. I made some reverse kerf linings for a couple and when I switched over to the solid I was really surprised.

_________________
Burton
http://www.legeytinstruments.com
Brookline, MA.

This is an experimental thin body archtop that I built for myself. Look inside, and there are no liners! The liners run the full depth of the sides, with a curly maple veneer over them on the inside. Stiff. We're talking Viagra-like. Weighs a little more, and while the sides are extremely crack resistant (fully bias-grain lined), I do worry about repairs if, say, it got smacked into the corner of a table.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I have been building my double sides with the grain of the inner lamination running perpendicular to that of the outside. Another idea I've been experimenting with is laminating fiber on the inside instead of wood. The first approach has produced good results and a stiff rim. I'm not sure yet about the latter though.

_________________
Don Sharp
Got Brazilian?
http://www.sharpguitars.com

Don, you're edging toward plywood! Seriously, has anyone experienced the cupping or bowing I would expect from a two-piece lamination, grain parallel? Especially using two disparate species? Cupping is not a problem with three-ply, the middle ply crossing. So, what are the objections to three-ply, since we're talking extremely stable, stiff as you'd want, and crack-resistant. Oh, and not, repeat NOT a tone hinderance (I have my sources on this).

Howard, the lined liner effect is the cat's patootie. Torsion boxes, yes! And with soundholes, perhaps offset, they could be tunable. Could there be a built-in reverb?

Dan

_________________
Dan
http://www.acme-archtops.com

Speaking strictly about laminated sides, my experience is that turning the middle layer to 90 degrees does affect tap tone of the rim assembly. It kills it on mine. Keeping the layers parallel has no negative effect, instead it actually provides a really strong tap tone. Surprisingly, the laminated rims are more resonant than a solid wood rim set. I also had more problems with warping when the layers were not parallel. Different strokes...

REALLY!!! Where are you getting .04" veneer?

That would make my life much easier.

_________________
Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Barry, I just ran over to the shop and tapped on everything in sight! The single BRW was pitched a little higher and had a slight "bong", and the three-ply maple was pitched a bit lower, but didn't seem to suffer any attenuation. These were both bent sides for a Rodriguez model classical. The five-ply three-inch-wide archtop side was pitched higher than either, and still seemed to not fall flat when tapped. One hardly knows where to hold a side for tapping; I found the friendliest spot on one edge where the part balanced, and then hunted around for a responsive tapping spot, but I gotta ask, does it matter? We're going to glue linings and then top and back plates to these things, and they're not being directly excited by the strings, and.....

OK, of course, everything on a guitar does matter. I just wish there was a way to build the same guitar twice, with just the one difference, and then A/B the snickers out of them.

Dan

_________________
Dan
http://www.acme-archtops.com

_________________
Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Hey, this guy is right near me. He works out of his garage, basically. He sells some amazing stuff.

_________________
Mike

"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Shoosh." The Stranger

Why would it be any worse than a solid piece (assuming the same species for both pieces)? I suppose if the plies were different thicknesses you could have problems.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Andy

Well, you may have seen a thin slice of wood curl away from the side you spread glue on (the wet side) as the cells on that face absorb water. I see it all the time when face-gluing veneer, admittedly thin and flexible stuff. It just seems to me that two different species, say a rosewood and a cypress, would curl different amounts and at different rates, and then, when clamped together, dry at different speeds while trying to exert their different rates of stiffness against each other, in other words I'd expect one to overpower the other.

Perhaps if one is gluing two pre-bent sides to each other the curves help the wood resist swelling and cupping, and if the parts are on the order of a mm thick they are even more resistant?

Yes, if you work with layers of different thicknesses things can get tricky - this is why the best quality plywoods tend to be built of uniform veneer thicknesses, with a balanced though odd number of plies in the layup. But then we're back to crossing plies, which tend to resist movement.

When I first started doing what I do I thought "Why not laminate an archtop plate with ALL the plies running parallel? Won't that more closely resemble natural lumber than crossplying?"

The first effort was such a flop I abandoned that approach. The three-ply spruce stack lost it's arch almost completely in a couple of hours, after curing in the mold overnight, and then went on to potato-chip spectacularly over the next couple of days. I had started with spruce 0.050" thick, but flat, not pre-shaped.

So there is the reason I was asking - my experiences in a parallel universe were not encouraging.

Dan

_________________
Dan
http://www.acme-archtops.com

Indeed....this must be part and parcel of laminating sides, especially using epoxy.

How many folks are using wood glue vs epoxy?

_________________
The member formerly known as erikbojerik....