Acoustic Guitar Construction

I use a mold INSIDE a vacuum bag to laminate my sides, but watching Michael's method, I think his is an even easier process.
He glues his lams together, puts them into the bag, turns on the vacuum pump or compressor, and simply spring-clamps to the form. It makes even that severe bend an easy thing to do. No heat involved.
So cool.

I have a set of sides and a back laminated by Michael Collins. They are exceptionally strong for their weight, which I expected. But the tap note of the back was low and the vibrations could be felt as the long amplitude variety. Nor did I expect them to be as light as they are.

I think laminated wood has a bad rep because it was mostly used in badly made guitars. Exception, of course, would be Selmer-Maccaferri instruments. Thus, lamination may be very useful in constructing deliberately light guitars. Collins uses high grade veneers and urea-formaldehyde glue, with a vacuum press (as Dave illustrates above), all of which might be part of the reason Selmer-Maccaferris sound so much better than '70s Yamahas. And so do Michael's own instruments.

Tops, I feel, still do best if made from solid wood.

Dave I'm looking at the bag process above -- honestly I am not getting how that set-up wraps the laminate around the curves, down the vertical planes and applies pressure. Is there a video somewhere? And what's the corrogated stuff in the bag?

I think the corrugated stuff is breather mesh.
The vacuum will press the lams together, as they are formed over the mold and dry in place with the clamps. I've watched the process on the Collins dvd, and seen similar things of a non-guitar nature on youtube.


Edit: I've contacted Michal Collins and will post his response.

From Michael:

"Hi Dave,

Your explanation is exactly correct. The bag squeezes the laminates, and the entire bag is held to the form until the glue dries. The mesh allows the vacuum to reach the far ends of the bag.

Michael"

I don't think this picture tells the whole story. I think you need to clamp the sides to the form. The vacuum only clamps the laminates together. Clamps of some sort, like the spring clamps on the lower bout, hold the lams to the mold shape until dry.

The upper picture tells the whole story.