I've used envirotex in two reptile cages and am so far very impressed with it. I've only used it in it's "normal" application - as a thick pour-on finish.
I know of one person who made a terrarium and had constructed his own pools, waterfalls, and fake rocks out of plaster. All the plaster was coated with elastomeric paint and then brush coated with Envirotex epoxy. The pools and waterfalls held water for 10 years with no sign of water damage.
So yes, you can use it on your cage furniture.
I've purchased this product at Menard's (a midwest home improvement store) and ACE Hardware. I paid $50 for a gallon.
I've seen an equivalent product available online. If I think of the supplier I'll post it.
In answer to number three, I'd say if it protects plaster pools for 10 years you should not have to re-apply it very often.
Also, I had coated the back of a face frame for another cage with Envirotex and that cage (fortunately empty) was sumerged under water for more than 24 hours during a flood I had. The front of the face frame, only sealed with water based Poly, suffered some damage. The back of the face frame is still perfect.
Another testament to the durability of Envirotex is that it is supposedly used to seal styrofoam surfboards. Given the beating surfboards take from saltwater and sand it should be durable for most reptiles and humid terrariums.
I would apply Envirotex over that water based product you used. In fact the manufacturers recommend two coats of water-based Polyurethane to allow the Envirotex to have a smoother surface to bond to.
Envirotex should be safe to use. I've used pool-paint epoxy in numerous cages and aquariums and have not had any problems with it. And pool epoxy is about the nastiest substance you can use.
The envirotex is solvent free and can safely be used indoors with no respirators or solvents. No doubt it's safer than pool epoxy. It's also approved to be used as a sealant for dishware if that makes you feel anymore comfortable with it.
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I wanted gett some envirotex epoxy for use in my reptiles cages. I just had some questions about. First of all, I wanted to seal all the cage "furiture" with envirotex so I could last longer and so it does not get all nasty in a high humidity enviroment. Can you do this with this epoxy? Second, where is this product available? Third, do you have to re-apply it after a period of time or does it last a long time? Oh, I used another type of sealant on my chameleon cage. I am not sure of name, but it is water based and it is a product that is commonly used in hospitals to seal any wood. It should be a safe product, but I am not sure about it. Should I apply envirotex epoxy over it, or do you think it is a safe product for reptile cages?