The Stovebolt Site Forums The Shop Area Paint and Body Shop Gas Cap Leaks Destroys Paint

Nothing like coming home after a long business trip to find your beloved truck's paint bubbling and peeling due to a gas leak. I peeled off the paint and washed the area and siphoned out some gas in the tank.

Is this normal? Can gas destroy paint in 3 days?

How hard is it to fix? Can a shop sand out the area and spray new paint and fade it in or do they have to reshoot a large area?

The paint is single stage mixed with clear.

Thanks for any advice. Below is a photo, hopfully you can see it without creating an account on Flickr.
Gas Destroys Paint


Michael

yes, it's "normal", it happens in hours not days - mine is currently worse than that

check with your shop, it can be fixed .... and next time don't fill the tank so full or else park with that side on a high spot

Bill

OUCH! :-(

I almost cried when I saw it.

Do you think a shop will need to spray a large area or can they blend it in?

Let this be a warning to you ALL!! Don't overfill your tank!

the overflow thing has been discussed here a number of times, it has to do with the colder gas out of an underground tank expanding as it warms up in the truck - and parking on uneven ground - always stop filling as soon as the nozzle kicks off, don't try to top it off unless you're on the road and will be immediately driving enough to run the level down

talk to a shop, it'll depend on the painter, but over spraying the bad area and compounding the edges to feather it in can work fine

Bill

Hardener is used in single stage paint to make it more resisitant to fuel, tree sap, etc. Mine is still OK after two yrs of use. I use a GM gas cap too.

Since it's not a metallic color, I believe the shop will have no trouble
in matching & blending it in to your satisfaction.

Makes ya wander what the heck is in the gas besides Ethanol!

I remember cleaning off bugs and road tar with 100 Octane Sinclair gas; on both lacquer and enamel cars of the 50s and 60s ...... worked great and didn't take paint off!

Spoke with a body shop and they said it shouldn't be too hard to feather it out.

They quoted $250 bucks to fix it so that isn't as bad as I thought it would be. But that is still money out of my pocket for doing a stupid thing!

Thanks for the responses.

Just out of curiosity, is there any chance at all that it leaked before the paint and that possibly they didn't get the metal treated properly? I am just wondering if the paint had good adhesion or if it was just waiting for another gas spill.

I have actually watched this happen on a motorcycle tank. The gas warms up in the sun and the vapors make their way between the top coat of paint and the primer or metal underneath. The gas cap seal prevents the vapors from escaping over and past the top of the paint. Eventually the paint gets hard enough that this wont happen but I think it takes months not weeks for paint to get hard enough. I almost cried to when I saw this happen :-(

Normally,gasoline will stain automotive paint,if not washed off immediately.I just read that in a google search.
What kind of paint did you use ?


Tim

I do not think that gasoline would damage properly applied and cured epoxy primer like PPG DPLF (I am not sure about self-etching primer), nor would gasoline harm a properly applied urethane final coat like PPG DCC Concept (2-part urethane, single stage).

I do not know about base/clear 2-stage urethane final coats.

I too do not believe gas would have destroyed the paint that much. I think we've all had some gas leak out from time to time. This would make me wonder about proper prep and paint work. So I tried a little experiment. I painted a piece of steel with some rattle can rustoleam primer, then some semi gloss. After drying time (overnight) I sat the painted steel in gas for a few hours. I did see a slight discolor to it, but did not strip the paint.

I am by no means a paint expert. Be interesting to know what happened.

gasoline is a solvent, quite like paint thinner, what it does to the paint will depend on how much gas, how long it's on, what kind of paint it is, how old the paint is [cured], and whether there has been any wax applied - sometimes it doesn't do much, sometimes it takes off the wax before it evaporates, sometimes it stains the top coat, sometimes it dissolves the top coat, it has little or nothing to do with pre-paint prep

Michaels pic looks like it took off the top coat and left the [probably epoxy] primer - also, in some cases like Michaels [and mine], the gas expands over time and there's more of a 'flow' of gas rather than a drip .... bottom line, do not overfill your tank and take a chance

Bill

Harking back to my days as a Boilermaker working in oil refineries in addition to all the other nasty components of gasoline one of the major additives is either HF or Sulphuric acid so paint eventually yields. I notice even when filling my tank I have to be very careful it does not burp out as it gets full. Hopefully it will be an easy fix.

This past summer I had an incident where the gas leaked from the filler neck area and I only had 1/2 a tank of gas in the truck.

I replaced the cap and problem stopped.

You do have to be careful with gas expanding when you fill the tank, but it still can leak at any level from a faulty vented cap.

I fill my truck on the way out

Greg,
The truck has been on the road for 2 years now without any issues so any paint problems would have reared their ugly head.

When I filled the tank I stopped when the nozzele clicked off, but it was a cold day in Florida, 65 degrees (sorry, bragging) then the next day it was 85 degrees. That may have contributed to the fuel spilling out. Maybe my garage floor leans one way too.

If my truck was beat up I wouldn't care, but that paint job was not cheap! Pisses me off!!!

I restored a 53 20 years ago and had the same thing happen. Back then the paint I used was an Acrlic Enamel with a cataylst. I hope the newer paints fair better.

How about a way to vent the tank other than the cap. Discussed on here anywhere? I will be trying this before spring and have my own ideas on how to do it. Will share if it works. '52 GMC pickup, tank in the cab.
Jim

Jim, it has little to do with venting, it's about temperature expansion of the fuel, just don't top the tank right up

Bill

An expansion tank can be used to eliminate any gas from leaking out of the gas cap. This design is similar to the expansion tank used on a radiator to capture coolant.

Reference this link for more information: Bilbo's Thread: What happened to my paint??

Hope this helps.

John (a.k.a. Lakeroadster)

Read again red58's recent post. That is a simple solution.

You can add an expansion tank, but it is easier to fill your tank before you go for a ride (preferably a 15+ mile ride), rather than filling it before parking it in the sun/etc. That way, the expansion of the gas will not result in over flow.

I've got the same problem. Gas run down under the fill hole and bubbled the paint up and put a nasty scar on my paint. The paint was 2009 Chevrolet red.