Fish Safe Epoxy source

I've got a 350 gallon galvanized stock tank I use for fish (yeah it's not glass)that needs some epoxy repair where some of the epoxy had flaked off. (the inside was coated with epoxy). AES has it in the gallon for both the epoxy and the primer. I sure don't need that much. Any ideas where I can get a much smaller quantity? Is it possible the aquarium epoxies will do the trick? I have don't have that much flaking.

What exactly is the objective? Is this going to be a load-bearing material, or just a corrosion inhibitor? If the latter, aquarium-safe silicone should be just fine. If you're trying to hold together seams on a tank that big, I think you'll need better advice than mine

I think he just wants to paint the tank so it doesn't rust or leach stuff into the water that is undesirable.

I think he just wants to paint the tank so it doesn't rust or leach stuff into the water that is undesirable.

Exactly. The areas where the epoxy had come off are rusty and the tank itself is galvanized. I got two of these tanks bartering and one is in use right now. I've tried regular silicone on the tank in use and it doesn't last.

Fiberglass resin will work, as will any marine grade epoxy. Fiberglass resin is available at Home Depot, or Lowes. Wear a respirator. Brain cells will die. Might want to use a rust converter first.

Fiberglass resin will work, as will any marine grade epoxy. Fiberglass resin is available at Home Depot, or Lowes. Wear a respirator. Brain cells will die. Might want to use a rust converter first.

Thanks Skipjack and others.

As far as braincells they deteriated long ago. I've had my share of fiberglass and lacquer work in my taxidermy shop! As long as I can throw the feed in the tank and seine the ponds I'm still here.

Edited by az9, 19 September 2010 - 09:48 AM.

Thanks Skipjack and others.

As far as braincells they deteriated long ago. I've had my share of fiberglass and lacquer work in my taxidermy shop! As long as I can throw the feed in the tank and seine the ponds I'm still here.

Cecil?

Cecil?

He's gone, this is the coroner. We found him floating face down in one of the fish tanks today. Must have been the brain damage.

Edited by az9, 20 September 2010 - 05:32 PM.

I have recently used a number of these products- fiberglass resin is readily available, and easy to work with, but unless it is covered in gelcoat can still be slightly less waterproof than you might think in the long term. It is also the cheapest- a gallon of resin costs about $35 and the hardener is $5, gelcoat is a bit harder to track down and costs a bit more, but mixes with the same hardener.

Sta-Crete makes an amazing epoxy called the Epmar SS1500 specifically designed for live animal tanks - the stuff works beautifully, but is very high VOC during the application, hard to get (you have to go through a regional rep, and it still takes a few months), and expensive (you have to buy 2 gallon lots at around $200-300 per lot)- will require some surface prep (sanding, acetone wipe, and primers, et cetera)

I've used several of the different colors of Aquatic Eco-Systems epoxy paints, they are also very high VOC during application, and perform very similar to the Epmar epoxy (very, very, very similar in my opinion) - it is a great product and I have it on a number of my tanks here at the Aquarium, it will also require some surface prep and possibly a primer, but that depends what you want to stick it to.

The epoxy I like the best for these types of situations is the West Systems clear epoxy, I like the 105 resin with the 205 fast hardener. It requires little to no surface prep for a good bond, dries really fast and crystal clear, and is fairly inexpensive (you'll pay about $70 for a quart of each part at West Marine). But the stuff is amazingly strong, folks have made homebuilt boats and aircraft with this stuff:

http://www.westsystem.com/ss/

Attached are some photos of recent epoxy projects, hope this is of some help to you
Cheers!

Edited by BLChristie, 26 September 2010 - 07:24 PM.

Great info from someone who is in the know! Nice set ups. Is the filter in the background of the first picture a bioreactor with kaldnes media? Looks a lot like the one I am using on a 1800 gallon project in my greenhouse. If so, what do you think of them? I am impressed so far, but am far from pushing it to its limits.

The bioreactor on that holding tank is one of the clearwater reactors from Aquatic- Eco (though it may be re-branded from another manufacturer), they have a very small bio-barrel type media and have massive aeration in the column- so far we are impressed with them, even the smallest models support a massive bio-load of fish and they hold true to their claims, just put some kind of mechanical filtration in line before them like a bag/pleat/sand filter so you don't clog the media with detritus and they work extremely well

Edited by BLChristie, 28 September 2010 - 07:10 PM.

The bioreactor on that holding tank is one of the clearwater reactors from Aquatic- Eco (though it may be re-branded from another manufacturer), they have a very small bio-barrel type media and have massive aeration in the column- so far we are impressed with them, even the smallest models support a massive bio-load of fish and they hold true to their claims, just put some kind of mechanical filtration in line before them like a bag/pleat/sand filter so you don't clog the media with detritus and they work extremely well

Thanks for all the info BL Christie! I only needed a small amount of product so was recommended to use a product from Sherman Williams called Tile Doc. I was assured it's inert and it sure is some tough stuff. Very very hard to sand or scrape off as after all the repairs were done (I removed the rust and recoated it with a rust destroyer before the epoxy), I found a leak in my central drain. It seems whomever installed it didn't bother to use a gasket and just bolted two toilet seat flanges back to back with the tank sandwiched in between!

If (just a matter of when) I move to a larger project I will save your post in my bookmarks!

Edited by az9, 10 October 2010 - 08:37 PM.

Thanks for all the info BL Christie! I only needed a small amount of product so was recommended to use a product from Sherman Williams called Tile Doc. I was assured it's inert and it sure is some tough stuff. Very very hard to sand or scrape off as after all the repairs were done (I removed the rust and recoated it with a rust destroyer before the epoxy), I found a leak in my central drain. It seems whomever installed it didn't bother to use a gasket and just bolted two toilet seat flanges back to back with the tank sandwiched in between!

If (just a matter of when) I move to a larger project I will save your post in my bookmarks!

The Tile Doc is a no go now! A fellow aquaculturist had doubts and after calling the manufacturer I've been told it's not for continuous immersion and therefore probably not fish safe! Not only have I wasted $45.00 but now I have to scrape it off and order another product! I'm starting to wonder when I will ever get this thing set up! This project has been nothing but delays!

That's what I get for listening to someone at Sherman Williams that doesn't know anything about fish!

Edited by az9, 12 October 2010 - 07:51 AM.

Sherman Williams is usually both protective about it's recipe and conservative with their application advice.
Is it a two part epoxy? If so, did it require equal parts hardener to pigment? If it's equal parts hardener to pigment, I would feel confident you have one of the toughest epoxy paints on the market and as safe as any epoxy product you could buy once fully cured.
If you think about it, why would a company say it's product is "safe" for fish? Saying something is "safe for a particular application carries legal liability. It's always "safe" to say you don't know.

Sherman Williams is usually both protective about it's recipe and conservative with their application advice.
Is it a two part epoxy? If so, did it require equal parts hardener to pigment? If it's equal parts hardener to pigment, I would feel confident you have one of the toughest epoxy paints on the market and as safe as any epoxy product you could buy once fully cured.
If you think about it, why would a company say it's product is "safe" for fish? Saying something is "safe for a particular application carries legal liability. It's always "safe" to say you don't know.

Actually he didn't say it was safe for fish but assumed it was because it is used in sinks etc. It would be nice to go ahead and use it but I'd take a serious financial hit if the fish got stressed or died so... If the manufacturer says it's not for continuous use I'd go with that.

It's not actually a Sherman Williams product though. Just sold by Sherman Williams.

Edited by az9, 12 October 2010 - 08:03 AM.

I ordered the West Systems 105 resin and 205 fast hardner and was delighted to find that they had smaller quantities and both came to only $58.00 without shipping including the measuring pumps!

Thank you BL Christy!

Edited by az9, 12 October 2010 - 08:09 AM.

I ordered the West Systems 105 resin and 205 fast hardner and was delighted to find that they had smaller quantities and both came to only $58.00 without shipping including the measuring pumps!

Thank you BL Christy!

I would not strip the epoxy off. I would scuff it with sand paper very well to remove any gloss, Dust it well, rag it out, and apply your new paint. Just my $.02.

Glad you found a good deal on the west systems stuff- it is an amazing product- just make sure you give it ample cure time- I would wait a couple days longer than the instructions specify, since if you don't the mixture will actually absorb some water (despite being completely hardened to the touch) and turn a milky white color...

I would not strip the epoxy off. I would scuff it with sand paper very well to remove any gloss, Dust it well, rag it out, and apply your new paint. Just my $.02.

My thoughts exactly!

Glad you found a good deal on the west systems stuff- it is an amazing product- just make sure you give it ample cure time- I would wait a couple days longer than the instructions specify, since if you don't the mixture will actually absorb some water (despite being completely hardened to the touch) and turn a milky white color...

Thanks for the advice!

If you ever need anything in the aquaculture industry let me know. I have a lot of contacts in the industry.

Edited by az9, 20 October 2010 - 11:21 AM.