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I've built all but one of the 8 odd guitars I've built with solid linings, double ply. Bent onto a form using heat blanket and clamped with clothes pins strengthened with rubber bands. Titebond original. Currently glueing cherry linings at 1.6mm thickness into an l-00, the top edges which connect to the back and soundboard are pretty perfect but there's gaps on the inside joint, usually around the waist. Any tips?

Thanks all

Shaped cauls with real clamps…

I use solid linings too.

I ran into similar issues getting the linings in place w/o gaps. Trouble is, the top or back being domed require the sides to be taller especially in the waist area. If you try and bend the linings to match the sides, the linings buckle or pucker making it impossible to pull them tightly to the sides while maintaining the same lining width around the guitar.

To make life easier I clamp the bent linings in place, tight to the sides, and draw a pencil line on the linings keeping width of the linings about equal where they hit the blocks. They will be narrower near the blocks.

Then I rough sand the linings to the pencil line on a belt sander at a slight angle to comp for the dome.

Then glue them in place.

Over the years I bought enough mini "trigger" clamps to do the more difficult areas as Ed suggested.

I think solid linings are worth the trouble, they really stiffen and stabilize the sides more than you'd expect from a small amount of wood.

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Brian R, Wood Mechanic
N8ZED

I do mine in 3 layers about the thickness of the sides (the first layer is done in prices between the reinforcement strips). I use wider strips than the finished linings will be. I laminate them together with clotheslines reinforced with rubber bands and little c clamps where I need more force. But, I don’t glue them together the rim while laminating. I get the in lined rim set close to the final dome/profile first so I can tell how wide I want the linings at any given spot.Once they are dry, I pop them out and trim up the “show side” of the laminate. Than I glue them in. The other side gets flushed up when I do the final bus driving.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I use solid linings, usually 2mm each layer, and invested in a heap of these, pretty good, about 50 lbs for clamping pressure.
No gaps, much better than previously with plastic clamp and added rubber bands.
https://www.screwfix.com/p/pony-jorgensen-spring-clamp-with-protective-handles-1-25mm-/428RG?tc=LC7&gclsrc=aw.ds&gad_source=1&gad_campaignid=21550393591&gbraid=0AAAAAD8IdPw33kf-1RN1T_jDyAZRSlgAl&gclid=Cj0KCQiAm9fLBhCQARIsAJoNOcsgpFGrH5b8LOuFlkTDGCNG0qUwQhffg8R8njzJuLwvpDkQmn5Zf1caAnQ6EALw_wcB

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

The number one thing that helped me with solid linings is to bend them on a form with the appropriate offset. It’s hard to wrestle the waist into place if you are bending them on the same form as used for the sides.

Also, check Burton LeGeyt’s solid lining tutorial here on the OLF for a genius way to deal with the back taper and still have consistent height block to block.

This shows what you get with an offset form - https://www.instagram.com/reel/DHOWAjzO ... d4ODZyNHk3

This shows the essential part of Burton’s tutorial to match the radius and taper of the back - https://www.instagram.com/reel/C-zOMGDO ... xpM2toaDQ5

Brad


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The only way I've found to avoid the problems of twisting, and the gaps that can produce, is to make the liners tall and profile them. I dry clamp them proud of the back edge once that's been profiled, and trim to the line. Then I trim them to a uniform height before gluing them in.

Brad,
Just to clarify, I assume by "offset", you mean that you bend the sides on one form, and then bend the linings on a different form that is reduced in size all the way around by the thickness (e.g. .085 or so) of the sides. Correct?

Correct. Ideally an offset that accounts for your side thickness and the thickness of anything “below” the wood during bending. Slats, blankets, etc… my sandwich is slat - wood - blanket - slat with brown paper on both sides of the wood so my lining bending form is reduced typical side thickness + lining thickness + .020” to account for the slat. Hope that helps.

Edit to add - You mentioned that the lining bending form should be-.085. Ideally your bending form for SIDES is -.085 (and again anything below the side like the metal slat).

If you think about the geometry of this whole thing, you have the outside mold which is one shape. Ideally you would want your side bending form to be that same shape minus side thickness minus slat (and blanket if that’s how you bend).

What happens in most cases is folks make the bending form the same shape as the outside mold and the builder is left to basically force the side into the mold.

It’s impossible for a manufacturer to know how thick you like your sides, etc… so commercial bending forms rarely take into account the side thickness.

Again, this is easy to overcome by forcing the side into place but, as you found, solid lining compounds the problem even further.

Hope that helps.

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