Official Luthiers Forum!

Is using top quality plywood for neck and butt blocks sacrilege?

I've used Baltic Birch for tail blocks for years but I still use solid mahogany for neck blocks. If it's sacrilege then call me half-guilty!

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JJ
Napa, CA
http://www.DonohueGuitars.com

I'm half guilty too

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

A luthier-made, custom built guitar with a plywood sumthin'.... well, I never...

I 3-lam Spanish Cedar blocks.

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https://www.facebook.com/profile.php?id=100008907949110

Martin uses plywood in their neck blocks for the mortise and tenon models. Must be fine then wouldn't you say?

Why on earth would anyone want to use something structurally superior to solid wood?

When I have time, I do make my own mahogany ply but it's hard to argue with apple-ply or baltic birch for the tail block.

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http://www.chassonguitars.com

I'm half innocent.

Some sort of laminate or a good plywood for the tail block is fair game IMO to prevent cracks from jammed-in end pins. I'm a little leery of using conventional plywood for neck blocks since half your gluing surface is end grain.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

I've talked about this with Jay Lowe who has a number of horror stories about plywood neck blocks. The problem arises with a glue-in type neck joint, which afterwards might need to be attacked with steam to remove the tenon or dovetail.
Said steam can also cause the plywood block some harm.
Namely, it can start to delaminate while the neck is releasing.
Of course, if you are using a bolt-on type joint, sans glue, you would be fine in regards to future repairs.

Steve

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From Nacogdoches...the oldest town in Texas.

http://www.stephenkinnaird.com

I believe that's........homemade plywood

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

I use a mortise and tenon neck joint. I make the neck block from mahogony but I use baltic birch ply in the area where the bolts go thru it. I use baltic birch on the tail block ah-la Larivee.

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Joe Beaver
Maker of Sawdust

Guilty.

Finish birch ply - wonderful stuff for bolt-in neck joints and slim butts!

Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

No slim butt here, but when I use up my supply of mahogony tail blocks, I'm switching to Baltic birch.

Baltic Birch does not break like mahogany will. A excellent Canadian luthier named Tony Karol told me he bought full sheets and used it for the butt joint connection. I have seen some builders use spruce baceing laminated with mahogany.

From a repairer's standpoint I would prefer to see plywood used for a neck block where the joint is a true bolt-on. On Martin's 15 and 16 series guitars (possibly others?) the tenon joint is glued - to end grained plywood - with a single machine screw used to hold the joint while the glue dries. As Steve mentioned above, the same steam that defeats the neck joint can quite quickly defeat the laminations in the plywood. The first one of these problems I saw was one that another local repairer brought over with the neck block separated completely from top to bottom. I was a bit suspicious of the amount of steam that had been used in that case. A not so severe delam happened to me sometime later when less than 60 seconds of steam had been used in the joint.

Another interesting one came to me after the owner had noticed a small separation between the neck heel and the body (which would indicate to me that the glue joint had failed) and he had read on another forum to just tighten the screw. He did. And crushed and splintered the lower part of the plywood block.

From what I've read here, It sounds like everyone is using an M&T joint that is far superior to the ones I've done work on.

Jay

Ply blocks sacrilege...naw...but while your at it don't stop there.... just make the whole guitar out of ply and I ain't joking. Think you will be very surprised at the sonic quality to say the least.


Blessings
the
Padma

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Audiences and dispensations on Thursdays ~ by appointment only.


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