Top stiffnes with lacquer added

[Roger Häggström]

Come to think about the lacquer we put on a spruce top without thinking much about it. But it's not just a protective surface and a thing of beauty, but it also makes the top stiffer and harder! The lacquer will act like a composite layer almost like a plywood with a hard plate with the soft wood underneath. With a hard lacquer like nitro or some modern curing type the top could be made thinner than with a soft one like shellac.

I wonder if this is a "thing" that is ever taken into consideration when making an acoustic guitar? An how much stronger will the spruce top be with lacquer compared with a top without it?

[Frank Ford]

With a maximum thickness of .009" I wouldn't expect much difference, and not enough to notice in use.  Maybe it could be measured, but I wouldn't bet on a double blind listening test to reveal any statistically significant difference, nor would I expect any difference in strength/stiffness.

Now, Ovation used a really heavy polymer lamination that really did add strength and stiffness.  On the rare occasion of finish removal, we noticed a nearly catastrophic loss of strength.

[Roger Häggström]

You are probably right. The Ovation reference made me laugh, so many things that was wrong! :-)

[Andrew]

I may be off the mark here, but my impression is that most suitable conventional finishing resins would typically add more weight than stiffness by the time the difference in stiffness would be noticeable/measurable. However, with the advent of materials like graphene.. who knows?