[deanmpereira]

Not sure if i'm in the right place but I have a question I cant seem to find a answer for.

I have acquired a few decorations that I would like to include in my 75gallon freshwater tank. The problem I have is they were painted with the idea that they would not be submerged in water. I am looking for a clear epoxy/clear coat that I can apply in order to preserve the paint on these items. However I do not want any toxins to leach into my aquarium over time and harm my plants/fish.   

I have heard that epoxy is inert once cured. Is this true?

Thanks in advance.

[curiouscat]

Exotic fish can be notoriously finicky. Even something considered inert for other purposes may sometimes be enough to disturb aquarium fish. Perhaps it is the inherent stress they face.

[Borek]

Also note that "epoxy" is a rather wide term, it can mean many different resins with different properties.

[deanmpereira]

Any suggestions on a particular product?

[Archer]

Unfortunately any coating will be a polymer made (cured) by the reaction of small molecules. In all cases there will be a small amount of unreacted material which may leach into your water over time. Particularly if you are using an epoxy resin which requires mixing of the adhesive resin and a hardener.

Personally I would not want to risk my precious fish but if you are willing to risk it the best that I can recommend is try a UV cure laminating resin that you would use to repair a surfboard.

These tend to be clear and hardwearing but best of all they polymerise upon exposure with UV rather than relying on the intimate mixing of two substances. Provided that it is given enough time to cure in direct sunlight this should minimise unreacted material which could harm your aquatic life.

Again my primary advice would be if in doubt, don't do it.

[curiouscat]

Any suggestions on a particular product?

What about glass or a glassy / lacquar-y coat?

I'd rather trust Silica or Borax or something like that than some nasty organic.

[Archer]

If you have one to mind try it. These may solubilise mores easily in water though,making the original paint more likely to come into contact with the aqueous phase.

[deanmpereira]

I was originally considering lacquer but I did find that most are not designed to be submerged for extended periods of time.

Surely there is a product im overlooking? How do they coat aquarium specific  decorations?

The surfboard epoxy does seem best as im sure it is more water resistant.