Acoustic Guitar Construction

I have used Hydro-coat --- but in fairness I never used Aquacoat so my comment may be an unfounded generalization.

I tried several. The Zpoxy and O'Briens plasterfill suit me most.
The plaster is a cleaner way to use, but it tends to color the surface and blur the natural looks. The Zpoxy leaves a better look, but as Ken says, it is messy.

I make two passes, first a filling pass and sand that down to the wood. After that a thin coat of Zpoxy covering layer. Little sanding on that, but not back to the wood.
When you see that layer, you'll doubt if all will be fine. But with laquer all blends in and leaves a great surface.
Herman

Hi John, what do you use to dilute the Zpoxy for that final coat.

Chris

I use denatured alcohol or everclear to dilute the zpoxy for a final wipe with a cotton rag. I have heard that it is important to mix the zpoxy first and then dilute. So I have always done that. I dilute until it is thin enough to wipe on. 20-30% or so.

Thanks John,
Just applied the first layer to the back.

Chris

When filling with Z-poxy, does the soundboard get epoxied, as well as the back/sides? I haven't found a comment on the topic. My impulse is to not seal the top with epoxy, relying on a shellac seal coat followed by however many lacquer applications are needed. Tops ain't the same wood as on the sides, save for those folks who build all-mahogany instruments, or all-something-not-spruce instruments. I suspect the all-mahogany instruments get their tops sealed with the same sealer as the back/sides.

Can someone please clarify this for me? And, yes, indeed, I can be quite thick inna head, on rare occasions. My wife and I have had many discussions about the rarity of such occasions.

Thanks very much.

Zpoxy in our arena, is for "pore filling" it is not a sealer coat. Its used to smooth "open" pore woods like Rosewood, Mahogany, Walnut, Koa, Oak etc. The softwoods normally used for guitar tops do not need pore filling, nor do smooth hardwoods like Maple, Cherry etc.