What happened to my gasket goop?

[Ivan Seeking]

I used some of this to fix a fuel leak on an old farm truck that we use around the property. It was used to seal a leak at the fuel inlet to the carburetor. The fitting is so old that it never even tightened up upon reassembly, so some good ole hardening goop seemed like an easy fix.

Permatex® Form-A-Gasket® No. 1 Sealant
Reliable paste-like gasket sealant/dressing/coating. Form-A-Gasket No. 1 sets quickly to a hard set and is recommended for rigid, permanent assemblies. Use to 400˚F (204˚C). Resistant to gasoline and other solvents. Conforms to MIL-S-45180 D. Suggested applications: Coating cut gaskets to improve sealing and hold in place

http://www.neverseezproducts.com/gasketseal.htm

When I went to use the truck the fitting started to leak again. When I pulled it apart, I found that the goop was nothing but a fine yellow powder.

As a kid and young adult I did plenty of mechanical work, esp rebuilding dirt bikes, and gasket goop was standard item, but I never saw it do this before. At this point there was nothing to lose, and some JB Weld did the trick just fine [put in an in-line filter to replace the one internal to the carb], but I don't understand what happened to my goop! Has anyone else ever seen this?

 

[FredGarvin]

That's strange. If it did, indeed, conform to MIL-S-45180 I would have expected it to be OK with diesel. There is a big move in our certifications in regards to using expired products. Do you happen to know how old this stuff was?

I always loved JB Weld. It makes the world go 'round, along with socket head cap screws.

 

[Danger]

Peculiar. I've used plenty of Form-A-Gasket in my time, and never heard of a similar situation.
Extreme age, as Fred mentioned, would be my first suspect, followed by possible contamination such as the tube not having been sealed properly for an extended length of time.
The only other thing that immediately comes to mind is the possibility of some pre-existing incompatible chemical on the parts, such as a lubricant, anti-seize stuff, or unusual fuel additive like octane boost.

 

[Ivan Seeking]

That's strange. If it did, indeed, conform to MIL-S-45180 I would have expected it to be OK with diesel.

A carburated diesel? Gasoline.

There is a big move in our certifications in regards to using expired products. Do you happen to know how old this stuff was?

It was brand new. I bought a new tube for the fix.

I always loved JB Weld. It makes the world go 'round, along with socket head cap screws.

... and PVC pipe, and standard epoxy...

 

[Ivan Seeking]

Peculiar. I've used plenty of Form-A-Gasket in my time, and never heard of a similar situation.
Extreme age, as Fred mentioned, would be my first suspect, followed by possible contamination such as the tube not having been sealed properly for an extended length of time.
The only other thing that immediately comes to mind is the possibility of some pre-existing incompatible chemical on the parts, such as a lubricant, anti-seize stuff, or unusual fuel additive like octane boost.

I don't think so. I have never used fuel additives and the parts were cleaned well.

Maybe it was just defective... very odd indeed. I can't even guess at how many tubes of this stuff I have used in years past, but I never saw anything like this.

 

[FredGarvin]

A carburated diesel? Gasoline.

HaHa. I completely blanked out on that. I figured "farm equipment.." must be diesel.

 

[Danger]

A carburated diesel?

It took so much effort for me to leave that one alone...

Maybe it would be worth firing a question off to the Permatex people to see if they have an idea of what happened. The worst that they can do is ignore you.

 

[Ivan Seeking]

HaHa. I completely blanked out on that. I figured "farm equipment.." must be diesel.

I knew that you knew better, but I had to say something because I am not of the same high caliber as Danger.

I probably will email Permatex. I'll pass along what they say.

 

[Danger]

I am not of the same high caliber as Danger.

I only hope that Tsu never swaps notes with W, who refers to me as a small-bore. :grumpy:

 

[Ivan Seeking]

The question has been escalated from email, to a phone call, to an internal issue. Everyone is stumped. The most likely explanation is excessive heat, but at 400F my truck would have been well into vapor lock before the sealant got that hot. There were no flags [known issues] on the batch either.

One interesting comment was made: This product is not compatible with ethanol fuel. For alcohol based applications they recommend a similar product having the product code 80088.

I should also mention that Permatex was very helpful and offered to send me free product to replace what I bought. They also wish to pursue this and see if an explanation can be found.

It is such a pleasure to work with domestic companies.

 

[FredGarvin]

That is very cool. I like dealing with companies like that. Out of curiosity, did they ask you for the lot number off of the packaging?

I would be worried with a 400°F carb temperature.

 

[Ivan Seeking]

Out of curiosity, did they ask you for the lot number off of the packaging?

Yes, and they may want me to send in the tube. They are supposed to call back and let me know.

At this point I tend to think it was a bad batch.

 

[chemisttree]

Do you think it is possible that the original application contained a holiday resulting in the leak? Perhaps the hardend material cohesively failed when you backed out the nut and the resulting debris caused a third body wear (and then adhesive failure) on the remaining thin layer. This debris could have resulted in further attrition of the material into the powdery substance you observed while appearing to not have adhered at all to the metal surfaces. Was the fuel line difficult to remove after the gasket seal hardened?

I also found out that the No. 1 sealant hardens by solvent evaporation. Probably not the best application for this type of repair. Dry times will vary with temperature, humidty and gap. Locktite 577 would probably have worked better. Anaerobic cure.
http://www.akd-tools.gr/xmsAssets/File/TDS/LOCTITE/loctite_577.PDF

 

[Ivan Seeking]

Do you think it is possible that the original application contained a holiday resulting in the leak? Perhaps the hardend material cohesively failed when you backed out the nut and the resulting debris caused a third body wear (and then adhesive failure) on the remaining thin layer. This debris could have resulted in further attrition of the material into the powdery substance you observed while appearing to not have adhered at all to the metal surfaces. Was the fuel line difficult to remove after the gasket seal hardened?

The threads inside of the carburetor that receive the fitting were stripped. I cleaned everything well, and it looked clean, but it is always possible that I missed something. One curiosity is that the fitting never got tight. Either the threads fails upon dissasembly or they had failed at some time in the past... which does make me wonder if this had been rigged once before.

I also found out that the No. 1 sealant hardens by solvent evaporation. Probably not the best application for this type of repair. Dry times will vary with temperature, humidty and gap. Locktite 577 would probably have worked better. Anaerobic cure.
http://www.akd-tools.gr/xmsAssets/File/TDS/LOCTITE/loctite_577.PDF

I did try to allow for this and let the truck to sit for several days before starting and exposing the sealant to fuel.

Due to the yellow color of the powder, they seemed to feel that the compound had undergone a chemical reaction. It starts off as a brown powder.


...Crud, what started all of this was a fuel contamination problem! Some joker put what looked like plaster in my fuel tanks when I was parked at Home Depot. It was over two years ago and I had almost forgotten all about it. I didn't think it got past the primary filters, but this problem started when I went to replace the internal carb filter as a precaution.