If no one knows of a safe clear coat I suppose I'll just go ahead and paint the interior and then add Wilsonart, expanded pvc, or something comparable, to the floor & the lower portion of the walls.
There are plenty of safe clear finishes, you just have to decide which is the right compromise for you. Here are some choices:
1)Sweetwater Epoxy (clear). This is a nasty, solvent-based epoxy but is completely safe once cured. It is rated suitable for potable water and is popular in the fish industry. You can literally make a marine aquarium out of plywood sealed with this stuff.
A couple of downsides, however. It probably will yellow and haze somewhat over time, although I have not heard this specifically about this epoxy. In general, however, the solvent based clear epoxies tend to yellow and develop micro-cracks in the surface which take away from the look, although they still do their job.
There is a gecko keeper who used this stuff a few years ago. I'll see if I can track him down and have him report on the appearance of the stuff after a few years.
2) Bonakemi Traffic. This is the cadillac of waterborn, catalyzed floor finishes. It is essentially a waterborne epoxy. Completely clear and stays that way for years. Also, a very repairable finish given its durability. Remember that as finishes increase in durability they tend to decrease in repairability. So that super duper finish is great until it gets scratched or fails somehow and you can't repair it.
3) Some of the better one-part waterborne polyurethanes. Target, Fuhr, and General Finishes all make good one-part "out of the can" urethanes. My one concern with these is how well they'll hold up to the urates of a burmese. Those first few inches of the cage walls could really take a beating.
I'll look up your location and see if there is a distributor of one of these products.
Seeing as how I'll be building the cage in 2 parts I might could clear coat the interior pieces and let them cure in the sun before assembling them.
Never let any finish cure in the sun unless the product specifically says to do so. Nothing breaks down a finish like UV, even the UV stablized ones.
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Current snakes:
0.0.1 Gonyosoma oxycephala - Java locale (green)
1.2 Gonyosoma oxycephala - Jave local (green)
2.2 Gonyosoma janseni - Seleyar locale (all black)
1.2 Gonyosoma janseni - Celebes locale (Black & Tan)