[AquaAurora]

So its been asked and answered by many in the past, yes you can use it in the tank.. but what brand have you used? I'd like to try clear coating some rocks in urethane so I can put them in the tank without the hassle of dealing with water params changing from whatever they would otherwise leech into the water. I've seen a few threads where people say "Yes its safe, let it cure and you're ready to go" but not as much on brands. I'd suspect anything "mold resistant" is bad and would kill BB, but other than that don't know any names of ones that are better/safer?

I'd love to hear what other members have used to urethane coat their.. whatever.. that went into an aquarium and worked successfully.

 

[lochaber]

I haven't used polyurethane, but I have done a couple paludariums using epoxy.

At least one with some epoxy bought by the gallon from a plastic supply place, and a couple smaller ones just using the stuff you can find in craft stores (scultping/mold stuff), or in hardware stores (paint/varnish stuff). It's typically advertised for making those bar/counter/table tops that have newspaper clippings, photos, and trinkets embedded in them. Usually advertised as being 'equivalent to 50 coats of varnish'. Not sure on the exact brand, but I've used a couple different ones and had decent results.

 

[chris_ranger]

I haven't used polyurethane, but I have done a couple paludariums using epoxy.

At least one with some epoxy bought by the gallon from a plastic supply place, and a couple smaller ones just using the stuff you can find in craft stores (scultping/mold stuff), or in hardware stores (paint/varnish stuff). It's typically advertised for making those bar/counter/table tops that have newspaper clippings, photos, and trinkets embedded in them. Usually advertised as being 'equivalent to 50 coats of varnish'. Not sure on the exact brand, but I've used a couple different ones and had decent results.

Envirotex is the brand name of the 50 coats of varnish epoxy.
http://eti-usa.com/envirotex-lite/
I was going to say this stuff is probably the safest stuff for inside a tank. I think people use it for plywood fish tanks.

 

[toriless]

Parks also makes a similar epoxy based product called Super Glaze.

 

[Dman911]

Drylok has worked for me.

Dan