Rust on bottom of fuel and water tanks

[Unicorn Driver]

Hi,

I need to sort out the rust on my fuel and water tanks on my workhorse UFO.

The shop I use will let me do the work while they are doing a muffler replacement.

What tool and treatment products would folks recommend?

Thanks,

[cruizerEd]

If it is something you think you can really scrape and clean thoroughly of oil and dirt I'd consider going with an epoxy primer and top coat. Personally I'm not sure you can do that without pulling the tanks.

If it something where you can't really get to it I would pressure wash it, wire brush it and spray things down with Fluid Film.

Fluid film seals pretty well so it will creep under straps and fitting. It can go over surface rust With the little hose extension you can get behind things. It stays on for a fairly long time and is cheap and easy to apply.

I wouldn't put on anything you think you might want to paint because getting it off for paint prep would be a real challenge.

[Unicorn Driver]

Thanks Ed,

I can get at it if on a lift but but not on the ground. I won't be able to pressure wash it in the shop while on a lift as it will be indoors. I don't care about cosmetics, I am looking to stop it rusting further.

We were thinking some kind of wheeled tool or a wire brush and a treatment such as rustoleum.

[ROUGHRIDER3]

Wire brush with power tool. Remove one strap at a time and brush where strap was and also brush the strap. Prime with epoxy primer and epoxy paint the area and the strap. When dry replace strap and go to next area and repeat. Zinc chromate is also an excellent primer. Be sure to do the straps or you will not have accomplished much.

I would also have the tank almost empty when removing the straps one at a time.

[Unicorn Driver]

Thanks for the reply.

I will only have the ramp for about 3 hours so it will have to be a quick job.

[Winemaker2]

Best rust preventive coating i have found / used is Por 15. It is very tough stuff. They recommend a top coat if exposed to UV but underneath no problem.
Lots of guys use this as a chassis frame paint when restoring. I used it in a battery compartment and very pleased. Can be brushed or rolled on.
I preped with wire wheels in a drill and sanding disc in a grinder.
Build yourself a set of ramps... I'll bet it won't be the last time you want to work underneath. Lots of posts on designs here.

[Blastvalve]

Another VOTE for for POR. I will caution you to cover all skin, it DOES NOT wash off, you will need to "wear" it off your skin.

If doing inside I would also caution to cover the bay area, the owner might not like POR on their floor as again, it WON'T come off!

POR makes a "chassis flat black" color that is nearly a perfect match to the OEM Winnebago underside. If top coating is needed (anywhere exposed to sun) then Rustoleum works well and is also a near perfect match.

[Unicorn Driver]

Thanks both,

It will need to be a product that's safe to use in a large shop.

Here is a photo of the shop from today.

[Fiesta48]

You'll think I'm crazy. I would clean up as much rust as easily as you can. Then coat it with any GREASE. It stops rust, applies easily, is cheap, easily reapplied in a year or 2. So what it picks up some road dirt. I've never had any success with stopping rust with any coatings. They just cover up the problem once started.

[veraken]

I used a product called Chassis Saver. You still have to wire brush and remove all loose rust. I found that Chassis Saver was easy to apply and did not need the prep coat. You can get it on Amazon

https://magnetpaints.com/underbody.asp

[Unicorn Driver]

Originally Posted by Fiesta48

You'll think I'm crazy. I would clean up as much rust as easily as you can. Then coat it with any GREASE. It stops rust, applies easily, is cheap, easily reapplied in a year or 2. So what it picks up some road dirt. I've never had any success with stopping rust with any coatings. They just cover up the problem once started.

I am ok with something like that also.

The rest of the chassis is in descent shape, the other rusty parts are around the storage bays which I can get at home.

[tcgoetz]

Mechanical prep is good, but I think you need to render any remaining rust inert chemically before you coat it with a product like this: https://www.theruststore.com/Rust-Bu...last-P376.aspx If you don’t convert any remaining rust, it will rust under your new coating.

[Unicorn Driver]

Originally Posted by tcgoetz

Mechanical prep is good, but I think you need to render any remaining rust inert chemically before you coat it with a product like this: https://www.theruststore.com/Rust-Bu...last-P376.aspx If you don’t convert any remaining rust, it will rust under your new coating.

Thanks,

I spoke to the rust store and ordered a product called Rust release super gel from them.

[MSHappyCampers]

I didn't know they made metal freshwater tanks!