Steam Driver

Has anyone (besides me) had any problems with Wurth Stone Guard Gray (fuel tank paint) drying? If so what's the cure?

I repainted the bottom of the used fuel tank I acquired for my SC at least two months ago, using the Wurth product in spray cans. I put it up in a loft area while it was still tacky to get it out of the way. The storage area was dry and believe me it should have gotten hot enough to cure paint. When I pulled it out a bit ago it was STILL tacky, enough so it stuck to my jacket and clothes. So what gives here?

LexVan

How old is the paint? Was it properly shaken? How did you prep the surface prior to painting? How many days drying time? What is the relative humidity right now?

Steam Driver

It was painted over the old factory surface after cleaning. The can was well shaken, I made sure of that. It has had plenty of time, temperature, and low humidity to dry, probably at least sixty days worth! Maybe ninety.

Steam Driver

More information on this.

The paint (?) after three months is the consistency of peanut butter, essentially. Xylol and gasoline both seem to be good solvents for it, and I will probably "wash" off the stuff Saturday.

The places where it didn't dry (95% of the bottom of the tank) are where it is over the old, factory-applied finish which I thought was also Wurth Stone Guard Gray. on areas where there was no old finish, such as the brass strainer, the inlet and outlet tubes, and place where there was masking tape the finish is dry as it should be, hard as a rock. Which means there is obviously a chemical incompatibility between what's available now in a spray can and what was originally applied.

I tried heating up a small area with a heat gun with no effects either positive or negative. My plan now is to remove the crap and refinish the bottom of the tank in spray-on black undercoat before I install it. What little Wurth there is on the top I will wipe off with a solvent and be done with it,

LexVan

[QUOTE="Steam Driver;10818513"]Which means there is obviously a chemical incompatibility between what's available now in a spray can and what was originally applied.[\QUOTE]

Ahh, that's what I was afraid of and why I asked the questions I did. Sorry. At least you have an plan of attack now.

Steam Driver

It's more than a bit disappointing (not to mention irritating) that the recommended refinish, which one would assume was like the original, would be incompatible with it. I suspect stripping the outside of the tank to bare metal would be a real chore as my guess is the original finish would be a bitch remove. I already know the radiator shop dip tank won't take it off. But it will destroy some of the metal fittings!

Steam Driver

I removed the spray-can version of Wurth Stone Guard Gray gas tank paint this morning. It took about an hour, and about a gallon and a half of gasoline, to get it off the bottom half - which is fortunately all I had painted. O'Reilly's brake parts cleaner also worked well as a solvent but is more expensive and I didn't have enough of it on hand.

But here's the bad news. Not only did the various solvents take off the undried parts of the coating, they also took off those sections on bare metal, masking tape, etc. that seemed to be totally dried and hard. Made no difference.

So does using a gasoline soluable coating to paint a fuel tank with seem like a good choice? Not to me it doesn't. "Originality" (and I'm not sure it is) can go away in this case.

And anyway, nothing is original once it's been reworked, even if the original materials were use.

Ed Hughes

Was the Wurth can new or had it been sitting around? Strange.

You may want to look at the POR product line. I love their stuff.

Steam Driver

Yes, the Wurth product was brand new (at least to me!) Cans looked new and all, like they hadn't been sitting on the shelf someplace for years. Had the Wurth red "W" on them. I don't remember where I got them; online someplace.

Really was weird. Why did it cure/dry/whatever on the bare metal and not the original tank coating, particularly since that coating seemed unaffected by either the new finish or the gasoline when I wiped (literally) off the sticky stuff. Why did it also wipe (just as easily) off of the bare metal and masking taped parts just as easily?

I recoated the bottom of the tank with Duplicolor paintable undercoating. I haven't checked yet this morning to see if it set up or not

whalebird

There are different versions of wurth stone guard. Some are water based and others are solvent based. I suspect that you may have a different product than was originally used. A detailed search through the Wurth catalog may clarify