Laminating sides, and a no water no heat bending method

[deadedith]

Brian Burns sent me the following info/pix, said it was fine with him if I posted it. Food for thought. Brian has built many outstanding classical/flamenco instruments this way.

From Brian -
Since I started making guitars again in '93 I have been laminating my sides. No heat, no water, just WEST system epoxy, and a vacuum bag.

The trick is to use 3 veneers. Two commercial veneers at .025" thick, and an outer veneer made from a set of sides that has been sanded to .045". At that thickness the wood just bends, without any need for pre-bending. If you look again at the .pdf of the cypress sides being bent, you will see two sides, of 3 veneers each, pressed tight to the outside mold by the vacuum bag, while the glue sets up.

Laminated sides are stronger, less prone to cracking, and always come out virtually perfect. I've bent several dozen sets without a failure. The process is even self healing as you can see in the last photo of the cypress side bending .pdf.
The molds are dual purpose. First you use them to bend the sides, and then you disassemble them, and bolt them to a plywood base to make your assembly form.

They are also dual purpose in the sense that you can use them to make the traditional standard size, and the more modern larger size guitar.

[Jim_H]

Neat! Thanks for those...

Bogdanovich does similarly laminated sides, but he does pre-bend the panels on the fox bender. He does his laminations in a similar mold, but uses cauls and clamps instead of a vacuum press.

[Kevin Sjostrand]

Yeah, I have the Bogdanavich book and have seen this being done there. Now, I thought that "solid wood" on a guitar was better than laminated wood....so, is this just a myth? Should we all be laminating??

Kevin

[deadedith]

For sides, laminates appear to have some real benefits. Somogyi uses side laminates, btw. For what that is worth.
Edit: Trevor Gore showed Brian Burns how much sides do move, thus robbing the top and back of a measure of their energy. Stiffer sides are better.

That is the main advantage of reversed kerfing or, as R.Taylor guitars use, actual solid wood kerfing - stiffens the sides.

[David L]

I hear all the reasoning, possible benefits, big name folks using them, etc... It's just the phrase "Plywood Guitar" makes me cringe!

David L

[kencierp]

Selmer Jazz guitars are constructed using laminates -- at one time I sold the forms which had a full outside profile and matching inside multi-piece clamping cauls -- pretty simple, made the sharp cutaway easy to form. No epoxy or vacuum just slow cure PVA.

[deadedith]

DavidL - it is just the sides, and is an upgrade not meant to save money but to improve structure and sound.
I use the reverse rounded kerfing and get some of the same benefits.

I get somewhat the same reaction to 'carbon fiber' braces as you do to 'plywood' guitars :-)

[tippie53]

Great points. While the side shape will be more rigid the actual side stiffness doesn't change at all . This is all about your preference , if you like it use it .

[deadedith]

Okay, you've badgered me into admitting that I misspoke: I meant more RIDGID. I don't suppose that is such a bad thing. Jeez.

Some days it's not worth chewing through the restraints.

[kencierp]

Easier to make
Easier to install
Easier to notch for braces
Helps the rim hold its shape
Looks better

And the negative is they may not make the rim stiffer then regular triangle kerfing? (which may or may not be a good thing)

Sounds like RR kerfing is running for political office.

Jeeez is right!

Personal preference to do it the old way -- seems the case -- which is perfectly fine.