Sanding Sealer Q's

[lowrider]

A couple questions, I'll try and make this as painless as possible. I purchased stewmac's water based sealer and laquer. Their directions state to put 12-16 half dry coats and level sand. First off, being a novice sprayer it was a little tough to get the half dry thing going. I did'nt get runs but prolly put 1/2 of the 12 coats on a little thick. A small section on the side of the ebony fretboard peeled up, and went a little on to the mahogany neck. I used a razor to trim that up, sanded down the "line" and wiped the area off with a 50/50 mix of denatured alcohol and water. I put about six coats on that area and I'm pretty sure I'll get it to where it cant be felt, what I'm a little suprised about is it looks like that line may be visible when all is done. I thought since they say it'll melt into itself that this would'nt be an issue.

As far as level sanding the sealer, do they want you to sand out every little crater or can that be done after the top coats?

Thanks, hopefully some pics of it completed to follow in a few weeks.

[syxxstring]

Your substrate, aka sealer, should be as good as you can get it. You can work out issues later, but it will be more work and come with a lot more risk of messing things up. Your final paint will be limited to a large degree by the underlying foundation.

I havent worked with the stewmac stuff so I can't help you there.

[Drak]

I was/am fairly certain (although I do not use them) that water-based products do -not melt- back in, and will show witness lines between spray sessions.

I found it interesting that you stated that they said the product will melt back into itself.

I thought that only applied to a 'window' of time, before the previous coat completely dries, as in a few hours max.

Basically, if you shoot 3-4 coats a day, those 3-4 coats will melt in to each other, but once you're done for the day, between sessions, there is no melt-back occurring, thus your witness line.

[lowrider]

Thanks for the advice. As far as melting into itself, it's their WB lacquer description that says 100% burn in.that. I dont see now where it says the sealer will. I'll have to call them on that maybe.

I went to their site:

ColorTone® Waterbase Sanding Sealer is a polyester/urethane lacquer sealer. 65-75% of the final finish thickness should be sealer. Sealer has a 48-hour “burn-in” window; successive coats will bond best when applied within 48 hours of each other. When this time is exceeded, sanding with 320-grit paper is required to roughen the surface for good adhesion of the coats to follow.

ColorTone Waterbase Lacquer

Clear gloss topcoat

A crystal clear, acrylic waterbase lacquer that has 100% burn-in between coats without a time limit. That makes it repairable, much like nitrocellulose lacquer. It is a thermoplastic resin and will shrink and move around with the heat of buffing. 25-30% of the final finish thickness should be lacquer topcoats.