rusting tank brace problem

[Reeferhead]

I've had my tank up and running for about a year now. Its an DIY acrylic tank with a power coated angle iron frame supporting the top edge rather than using a euro brace. The guy that did my powder coating said he would use 5 coats and that it would never rust... that was BS. The powder coating started to chip and the frame rust within about 6 months. It is now a serious issue and I need to do something about it.

I can't remove the brace and have it recoated without breaking down the whole tank. Is there any kind of marine paint or epoxy I can use over the rust spots? The brace is not in contact with the water. It sits about and inch above the water line.

Thanks

 

[Chrsnwk]

the only think i know of that you could do it to temporarily clamp the tank near the top to brace it, then remove and properly repair the existing brace. instead of powdercoating, maybe have it line-x'd (the spray in truck bedliner stuff) much tougher.

 

[scrager]

so the problem is that the powder coat chipped, not that it rusted through. if the powder coat didn't chip, it probably wouldn't rust.

i would suggest por15. not sure how well that will work though with it on the tank since it is supposed to be applied to clean dry metal, but you can apply it over rust.

i would suggest bracing the tank some way, taking off the rim, removing all the powdercoat and painting with por15. por15 is very tough and bonds with the metal. it is very hard to chip it if at all.

 

[Reeferhead]

The Por15 looks promising. I may drain the tank down halfway, remove the brace, clean it up, apply the Por15, and put it back on.

I wonder how well the por15 will bond to the powder coating? I really don't want to have the whole brace sandblasted just to get the powder coating off. I'd rather just touch up the spots where it has cracked and the metal is rusting.

 

[scrager]

por15 is designed to stick to metal. I would sand the powdercoat to rough it up and give the por15 something to stick to.

As long as the powdercoat does not chip anymore, you should be fine. The powdercoat will cover most of the metal and keep it from rusting. the por15 will protect any metal exposed from chipping.

You may get run creeping along under the powdercoat and possibly causing it to chip off later on (like rust bubbles on a car), but that will probably take a long time and you can do the same thing again when that happens.

Another thing to note is that por15 does not have a long shelf life. Once it is open, it will start to harden and bond to the can since the can is metal. Since you have to buy a certain amount anyway, you might want to consider blasting or grinding down the brace and doing the whole thing in por15 now so you won't have to buy another partial can later on.