Tuesday, July 17, 2012

Propane Tank Rust

My propane tank has some rust spots on it. Most are tiny and superficial, but there is one about the size
of a quarter that is all rust, no paint, and rough to the touch, plus the paint around about half of it is blistered a bit, making me thing there is rust under there too.

My inclination is to wire brush and then sand these spots to see how quickly I get a smooth bare metal surface. Then, if the rust is shallow (i.e., no noticeable indentation vs the surrounding surface), treat with a rust inhibitor paint, prime and top coat with white Rustoleum.
So, I'm just wondering if others have experience with this and any recommendations. Thanks.

Terry, Gardnerville, NV

I want to thank everyone who replied to my post below. I began work today, scraping and wire brushing the rust spots on my propane tank. There was more rust than I previously thought, probably 10 or 12 sq. inches altogether. The paint chipped off the rust spots fairly easily. I then wire brushed those spots and sanded the whole lower half of the tank, cleaned it with paint thinner and then cleaned that off.

I then treated the rusty spots and surrounding paint with Rustoleum Rust Reformer. This "converts" the rust to something that won't rust further and seals everything. It's flat black. Next steps will be to spray the whole bottom half of the tank with Rustoleum Stops Rust flat white primer and then top coat that with Rustoleum Stops Rust gloss white paint.

Terry, Gardnerville, NV

Here is another issue that I have been running into on LDs that are a few years
old. Many, if not most LD's, with horizontal, frame-mounted propane tanks, have
rusted bottoms, with the rust extending up the sides of the tanks, under the

I found a third of the propane's tank covered in rust. I scrapped all the loose paint and rust off
and treated it with Naval Jelly and then two coats of hammertone enamel paint.
A couple summers ago, I found almost all the paint missing from a 2003 East
Coast LD's propane tank. Road salt may accelerate the problem.
The tanks have what appears to be an epoxy coating applied over a surface that
was not prepared correctly.
You might want to take a look at your tank to see if it is suffering from this

The best cure I have found is to scrape every bit of loose paint off, treat with a rust converter, like Naval Jelly, and then give it a couple coats of a durable paint.

Rust never sleeps.


Just to clarify, Naval Jelly is not a rust *converter*; it's a gelled acid rust *dissolver*. While effective for removing heavy rust deposits, it must be thoroughly washed away after use, or it will promote future corrosion. Even after it's been removed, the resulting surface is just as vulnerable to rust as bare metal.
In most cases of light to medium rusting, a better bet is a converter product such as Rust-Oleum 215215 "Rust Reformer":

Products of this type actually *convert* rust to a chemically inert form, leaving a barrier that prevents further rusting. To work properly, they need some rust to convert, so the instructions typically recommend removing excessive loose rust, but leaving a thin layer of rust, then applying the rust converter liquid.

Andy Baird

I have used rust converters and dissolvers and both, in my experience, do a good job as long as the directions are followed.
Naval Jelly removes the rust and allows the fresh paint to get a good grip, a sort of chemical sandblasting.  Apply it liberally, allowing time for the acid to creep under the chipped edges, where the rust is actively expanding. Then scrape the area well with a heavy wire brush or stiff putty knife to remove any loose paint. Wash the surface well and wait until dry before top coating.
Whatever method is used, be sure to re-inspect the area periodically and touch up fresh chips, they will continue to occur.