Priming galvanized steel for painting

A friend has offered to give me a galvanized steel livestock trough. I'd like to give it a coat of epoxy paint prior to putting plants and critters in it. I've already got some Sweetwater epoxy paint. The trouble is, the Sweetwater metal primer only comes in a large and expensive kit. Is there any substitute I can use to prime the metal prior to painting? The information I've been able to find online is conflicting.

Have you thought about using Zavlar®? That way you'd only need one type of coating. It adheres to metal and is safe for fish.

Adheres to metal:

In agricultural applications, Zavlar™ is used to provide a corrosion protection for metals used in barns, feeding stations, and silos.

Source: http://www.russlar.com/products/zavlar

Safe for fish:


There's a coverage guide here so you can see how many gallons you'd need to buy to cover your surface area.
Link (bottom left of page): http://www.russlar.c...atasheet-en.pdf

Edited by EricaWieser, 05 October 2011 - 11:58 AM.

I never use primer when using epoxy on steel. The primer is usually inferior and causes more trouble than it's worth.

I've never painted galvanized steel but I will say it (galvanization) can be removed pretty easily if you feel the epoxy paint will not adhere to the galvanization.

Sherwin Williams sells a primer or used to sell a primer specifically for galvanized steel. The product name was "Galvite" if I remember correctly.

The constant water immersal will likely be problematic but i think you are on the right path with an industrial epoxy and no primer. You should be able to buy a gallon of it at any paint store.
You can increase the adhesion of whatever paint / primer you use by washing the galvanized surface with vinegar.
The vinegar etchs the surface.
An old sign painting trick.

I did a test once washing half a panel with vinegar. My fingers would slide on the untreated area yet squeak / grip on the etched surface.

Thanks all for the help!

Erica- after some research, I learned that Zavlar is the same product sold as Permadri Pondcoat. I couldn't find any info definitely stating that Pondcoat/Zavlar will adhere to galvanized without primer. In any case it would cost me as much as the Sweetwater primer, and I can't afford that right now. I will keep it in mind for future projects, though.

I think I will try a test with Casper's vinegar-etching trick.

Thanks all for the help!

Erica- after some research, I learned that Zavlar is the same product sold as Permadri Pondcoat. I couldn't find any info definitely stating that Pondcoat/Zavlar will adhere to galvanized without primer. In any case it would cost me as much as the Sweetwater primer, and I can't afford that right now. I will keep it in mind for future projects, though.

I think I will try a test with Casper's vinegar-etching trick.

Mkay. Etching sounds smart; it's the same reason we sand wood before painting it.

Just wanted to make sure you had the same pricing info that I had, though. If you look at the video I linked to, that uarujoey user claims to have paid only $38 a gallon and to have used only two gallons on their tank build. That's much cheaper than epoxy.

Edited by EricaWieser, 06 October 2011 - 12:49 PM.

Yeah, but he's in Canada. The pricing I've seen is considerably higher. Plus- I already have epoxy.

How large is your tank? Aquatic Ecosystems sells liners for many of the larger livestock tanks.

Edited by Skipjack, 06 October 2011 - 05:56 PM.

How large is your tank? Aquatic Ecosystems sells liners for many of the larger livestock tanks.

Neat! I'll have to try to find those. I don't have the tank yet, but I think it's a fairly small, shallow trough. I plan to use it in conjunction with a 150 gallon plastic tub I already have to make a sort of two-level emergent plant garden.

*EDIT* Oh, those are for huge tanks. I wish I had something like that!

Sorry, Did not know what you had, or your idea of a "huge" tank. Best of luck. Unlike some other members comments, I am a fan of primers. But depending on your topcoat, it may not matter too much, as you will have an impermeable membrane supported by the trough. May not matter how well it adheres. Honestly, get an appropriate EPMD liner, and never worry about it again.

I have two circular galvanized stock tanks right now that were given to me, and I'm in the process of stripping the old epoxy off of one right now due to deterioration and rust of the tank. I will be repainting with the Sweetwater primer and epoxy coating any day now. I can tell you it's NO FUN stripping epoxy and I couldn't find anyone interested in sandblasting or media blasting the tank. I will be using rotomold low density polyethylene stock tanks in the future for my recirculating systems and here's why:

1.) When you're done you will end up spending more on coatings and using more labor on a galvanized tank than if you bought a plastic tank.

2.) The tanks below are fish safe and USDA compliant.

3.) There's no waiting period to wait for the epoxy to cure.

4.) Epoxies don't last forever and all it takes is for a there to be an opening and water will work it's way underneath, rusting your tank, and breaking down the epoxy.(Yes even galvanization breaks down over time)

Here's what I will be going with in the future.

http://www.ruralking...stock-tank.html

They come in all sizes and I can pick them up at the store and not have to pay shipping charges. Only downside is they are special order and need to be prepaid, but that's not a big deal. Notice the lower prices vs. fiberglass etc.

Edited by az9, 07 October 2011 - 10:15 PM.

A friend has offered to give me a galvanized steel livestock trough. I'd like to give it a coat of epoxy paint prior to putting plants and critters in it. I've already got some Sweetwater epoxy paint. The trouble is, the Sweetwater metal primer only comes in a large and expensive kit. Is there any substitute I can use to prime the metal prior to painting? The information I've been able to find online is conflicting.

I was in the same boat on whether to pay the additional cost for the primer. I ended up biting the bullet and buying it anyway.

Thanks, az9. I'm considering just building a plywood box and epoxying that instead of dealing with the troublesome metal trough.

Thanks, az9. I'm considering just building a plywood box and epoxying that instead of dealing with the troublesome metal trough.

Also, with a wooden box you could put a pond liner in, too.

Thanks, az9. I'm considering just building a plywood box and epoxying that instead of dealing with the troublesome metal trough.

Newt,

How about selling your epoxy on Ebay and getting one of the plastic circular tanks (link above). No labor involved and you'll save money by not having to use the epoxy or building the box. I can show you how to make a circular tank self cleaning if you cut a 4 inch hole in the center, install a Uniseal for about $60.00 (better than expensive bulkheads) and use some 3 inch PVC and elbows etc. A 55 gallon drum becomes your clarifier and depending on your fish load you can get by with a store bought upflow filter for under $80.00. I however use an RBC which I built.

Edited by az9, 10 October 2011 - 07:14 AM.

Also, with a wooden box you could put a pond liner in, too.

Don't you end up with folds, creases, etc. that collect waste? And the fact that many are very dark in color makes it hard to see this debris doesn't it?

Thanks for the offer az9. I would be very interested to see your method, but you're talking about a much more involved system than I plan to build. Sorry for not being more clear. The tank I was offered was quite small- I haven't seen it yet, but believe it's on the order of a foot deep with a 2 X 4 or 2 X 6 footprint. If I build a plywood substitute it will be about the same size.

My plan is to set this small shallow tank up on a platform or table just higher than my 150 gallon stock tank. Then I'll plumb them together and pump water from the lower tank to the upper one and let it drain back through a stand pipe. The idea is to propagate emergent plants in the upper tank, and perhaps a few fish in the lower one.

Thanks for the offer az9. I would be very interested to see your method, but you're talking about a much more involved system than I plan to build. Sorry for not being more clear. The tank I was offered was quite small- I haven't seen it yet, but believe it's on the order of a foot deep with a 2 X 4 or 2 X 6 footprint. If I build a plywood substitute it will be about the same size.

My plan is to set this small shallow tank up on a platform or table just higher than my 150 gallon stock tank. Then I'll plumb them together and pump water from the lower tank to the upper one and let it drain back through a stand pipe. The idea is to propagate emergent plants in the upper tank, and perhaps a few fish in the lower one.

Not a problem. BTW the $60.00 above was supposed to be $6.00.

I'll post my system in the future when my regular PC is back up and running and I can access my browser again.

Edited by az9, 10 October 2011 - 07:50 PM.

Have you thought about using Zavlar®? That way you'd only need one type of coating. It adheres to metal and is safe for fish.

Adheres to metal:
Source: http://www.russlar.com/products/zavlar

Safe for fish:


There's a coverage guide here so you can see how many gallons you'd need to buy to cover your surface area.
Link (bottom left of page): http://www.russlar.c...atasheet-en.pdf

Erica,

Is this product available in the states? When I saw where to buy it mostly listed Russia.

Edited by az9, 01 November 2011 - 08:27 PM.