Not sure where is the right place to post this, so I figured “Everything Else” sounded good.
I’m currently working on some coaster designs, because, well, who doesn’t want to make some coasters right? I’m making them currently out of Proofgrade plywood materials. I’m thinking that they probably need to be coated in something in order to seal them and protect from moisture, at least on the tops. I’ve got cork for the bottoms.
So my question: I’ve been searching and reading online and seen various people use spray spar eurethane, others use brush on marine spar, others use a brush on clear lacquer. I’m not really familiar with these materials / methods and was looking on some advice for the easiest and best results in coating coasters. I’ve tried using spar eurethane spray but I’m getting mixed results for evenness of coat and it takes a lot of time to spray it, wait for it to set, sand, spray another coat, rinse and repeat.
Against conventional wisdom, I say just leave it alone. I have a coster sitting next to me that is over a year old and has not started to deteriorate. Obviously, YMMV depending on how deep your engraves are and how much your glasses sweat.
Two different coaster types right now. One is engraved, and one is just multiple material cuts. These aren’t necessarily what MY designs will be, but they were easy to pick up vector files of the net and get playing around with it and the process.
Engraved (Some just engraved, some just painted as I mess with different styles of finishing):
I had thought about just letting them be as well, just haven’t had time to test wet glasses on them for extended periods of time, so wasn’t sure how bad they would absorb the moisture and distort/stain. Good to know you’ve had good luck with them without any coating.
I used a water-based polycrylic and my coaster warped almost immediately. I tried it on the Medium Maple Plywood Proofgrade with a pretty deep engrave. The spray shellac looks promising! Right now I’m trying a brush-on shellac with a one-hour dry time.
Okay, I can give it a try If for nothing else just to learn more processes for finishing work. Definitely adds some time onto the creation of the items, and a bit of cost. Hoping to eventually have a coaster design I can sell.
I noticed you have some nice colors on some of those. Be mindful to use a varnish or shellac that is compatible with the paint you’re using on a given piece. The Bullyseye shellac above is good stuff, and will seal enamel wonderfully, but will fog badly over water-based acrylic paint. There are water based laquers, but of course they have their pitfalls as others have mentioned in this thread. The main thing to keep in mind is coasters are born to die, but the cut files last forever. You’ll never create an indestructible one, but they’re easy to re-do. One final tip - lacquer is for people with time on their hands. Spray it, let it dry pretty thoroughly, then give it a good scrub with some fine steel wool, then re-apply. Three or four light coats may take a few days, but the extra time spent with steel wool between coats really pays off IMHO. I particularly like that inlay idea btw. Nicely done.