Epoxy

[3_high_low]

Eric,

The epoxy shown in your Reef Insiders article is steel filled. It will rust if used in a marine aq.

Mark

[EricHugo]

Hi Mark:

It was a mistake that I bought a steel-filled epoxy, and subsequently used it in that photo. I regularly warn others to watch for steel, copper or other fillers in epoxy.

That said, it really doesn't rust in tanks. Epoxy is rather water impermeable and is used in making watertight underwater reapirs. The only thing that could rust is the surface, and I see no signs of that happening. Even if it were to rust, or "leach", it's really only iron at levels so miniscule that there would likely be no effect at all, and tanks are generally low in iron anyway. So, although it was unintentional, I don't think anything bad would happen as a result, and since I have used the better part of half of that tube and see no ill effects at all, I can sort of anecdotally confirm that it is safe in marine aquarai.

[3_high_low]

Hi Eric,

I used it in my tank too. In a panic I removed it a couple weeks later and it had rusted. Just to make sure I was seeing rust and not dinos or brown algae I did a test. Just two days ago I placed a piece of it in a cup of tank water and then put the cup in a cabinet away from light, it is already showing signs of rust.

Isn't steel an alloy? I know there is iron in steel but what else?

Here is the MSDS:

http://www.oatey.com/apps/catalog/instance_assets/assets/MSDS_Sheet/Epoxy_Putty.pdf

It seems as though there are other metals in this putty.

Thanks for your attention to this matter.:)

Mark

[3_high_low]

Eric,

I won't venture to say whether or not the steel filled Oatey epoxy is reef-safe or not and I'd tend to take your word on it but hopefully I've found some info that will help make the call with more certainty, one way or the other.

I realize MSDS do not list all ingredients and that these are products from a manufacturer other than Oatey but section X of each MSDS might shed some light as to some of the differences between this manufacturers steel product, FastSteel, and the reef-safe Aquamend.

To save you some time it looks like the the FastSteel product lists iron, silicon, titanium, and aluminum alloy in section X and the Aquamend product does not.

MSDS sheet for "Aquamend", which I believe is accepted as being reef-safe:

http://www.polymericsystems.com/PDF_Files/AquaMend%20MSDS%20(11-13-02).pdf

...and MSDS for the steel filled epoxy product, "Faststeel" from the same manufacturer (not Oatey):

http://www.polymericsystems.com/PDF_Files/FastSteel%20MSDS%20(11-13-2002).pdf

[EricHugo]

Thanks....I also did a little research on steel, and figured the same. As we both agree, probably best not to use any filled epoxies.