Has Anyone Stripped and Repainted Steel Tanks?

[Tamas]

I'm in the same boat, I'm about to strip/blast my OMS 98's...hmmm I wonder why it's always the 98's. After some research here's my plan:

1) Using a softer media like walnut shells to blast the paint off. My understanding is that you can use sand, but you have to be quick and careful.
2) Through scrubbing, rinse and dry (no heat)
3) Base coat with ZRC cold galvanizing compound in aerosol form (found it locally @ Gaspro)
4) Spray a clear coat of urethane paint.
5) Air cure for 48+ hours.

You could use coloured paint, but I dig the grey and I want to see any damage/corrosion.

Hey Tamas the Emron is the crap OMS put on there in the first place, you really going to put it back? Primers aside.

NOTE: Napa does not carry ZRC only a low grade Zinc compound.

Good plan! I like the cold galvanized coat.

Yes, that is. But the problem was with the primer not the top coat. My other tanks, which is a year older is fine.....same top coat but different primer (they wised up after the first batch of bad tanks). Problem solved. This paint is automotive/marine based and is guaranteed for 15 years (according to the auto body dude)

 

[MilitantMedic]

Thanks, I'll let everyone know how it turns out. Yeah the ZRC stuff is only like $8 a can..not bad for Hawaii. Just hope the rust isn't all that bad.

 

[laughintom]

$8 per can?!?!? I just ordered the gallon for $115 plus shipping from the manufacturer. Also, aircraft stripper works great on the paint but does not remove the primer which seems to be the problem area with these. Any suggestions on getting that damn primer off?

Tom

 

[MilitantMedic]

@#$%^.....I was qouted 7.98 a can....I hope it's the ZRC!!! Sandblast the primer...that's my plan.

 

[cnctina]

$8 per can?!?!? I just ordered the gallon for $115 plus shipping from the manufacturer. Also, aircraft stripper works great on the paint but does not remove the primer which seems to be the problem area with these. Any suggestions on getting that damn primer off?

Tom

sand blast it off. the primer needs an etched surface to bond to, other medias (glass, walnut shells) are not aggressive enough and leave a more polished surface.

 

[Tamas]

sand blast it off. the primer needs an etched surface to bond to, other medias (glass, walnut shells) are not aggressive enough and leave a more polished surface.

what about the argument that sand-blasting will condemn the tanks?

 

[MilitantMedic]

If your media is to coarse you would start stripping metal, if you use a softer media such as walnut shells you would be ok. If in doubt hydro!

 

[cnctina]

Failing the hydro test is what condemns tanks, not pealing paint, surface rust, or sandblasting. If your tank has so much rust on it that sandblasting is going to peel the metal away, I dont think it's going to pass the hydro anyway.
A lot of paint failures is from non compatable primers and topcoats or improper prepwork or applications.

 

[Jim Lapenta]

There are different grades of sand. If you are worried don't use some thing coarse like black beauty, go for a softer stuff like aluminum oxide type. we use this to prep aluminum castings. It will strip the paint but not really affect the steel other than to give it a profile. It will remove the rust.It will take a little longer though. You could also have it soda blasted. Can't comment on the cost of the zrc mine is "surplus" from work.

 

[fishoutawater]

I gotta interject here. Laughintom did say his tank has surface rust, so I can assume his is a steel tank. The wire wheel and cold galvanizing would be great for that, but I'm worried someone with an aluminum tank would try the same method.
Do NOT use a steel wire brush on an aluminum tank. Traces of the steel wire brush will become imbedded in the surface of the aluminum. This will cause galvanic corrosion, which is caused by placing dissimilar metals together. An electrical current is induced between the steel traces and the aluminum, and will corrode no matter what you paint it with. Same for the cold galvanizing compound. Although next to each other on the galvanic scale, zinc, like steel, will react with the aluminum and eventually cause corrosion, especially in salt water.
(I'm an Inspector on fighter jets. They drilled this into my head years ago)

And Militantmedic,
I've had trouble getting paint to stick to cold galvanizing coated parts. I also build custom cars. I only use CG on hidden undercarriage parts and between welded seams.
It's pretty tough stuff by itself though, and would look good on a tank.

But if you have an aluminum tank that needs refinishing, use only aluminum oxide blast media or paper (no wire brushes or steel wool). Then paint it with epoxy primer and epoxy paint.

Jimlap, you can't powdercoat aluminum? I know how hot powdercoating is, but aluminum doesn't melt before about 1400 deg. (Might weaken it though) But if it won't hurt the tank, it sure seems like it would be the way to go. Very tough stuff.