Technical Gasoline Sealant

I used to use Dow Corning RTV 730 for sealing gas tanks, carburetors or other places where a gasoline leak proved difficult to stop. It works really well but is ridiculously expensive.

I had a leak on my 49 Buick around the sending unit for the fuel gauge and it was mostly leaking around the screw threads when I stopped the tank off. I needed something to apply to the threads to stop the spiral leakage permanently.

So, I did a search for gasoline resistant RTV and came up with a new one that seems to work really well and is a lot less expensive than the Dow Corning 730. It's made by a company called Silicone Solutions. Here is a link. Hope it works for you.

https://siliconesolutions.com/ss-300.html

 

Keep in mind , resistance doesn't mean proof ..

 

Your post is right on time. I have the same issue with leakage around the sending unit on my O/T pickup. When I installed the unit I used a Permatex sealant recommended by the tank manufacturer. I do not recall the product name, but it hasn't worked well. Next time the tank needs filled I plan on attempting to seal it again. I'll look into your suggestion.

 

I happen to have part of a can of gas tank sealer from trying to save an old tank years ago. I have used a smear of it on the gaskets and a dab on the threads of the screws on the last few tanks I've done. It's also expensive, but if you happen to have some, it works good.

Gary

 

Keep in mind , resistance doesn't mean proof ..

Nobody is going to put "proof" on their label.

 

The Permatex stuff I have used never hardens, it remains in a gel state, and I have never had it fail. Of course, now that I said that...

 

Is that the orange Permashield? Just “fixed” a leaking fuel shutoff for OT tractor with a piece of felt drenched in Seal All, so far so good

 

I've also had success with Seal All.

 

Seal All for me too, but it's getting hard to find around here.

 

I've used Hylomar to seal fittings and gaskets exposed to gasoline. Worked good for me.

 

Heard fantastic stuff about Hylomar, used by high end English automakers. Was about to order some, then stumbled on this. Supposed to be equivalent. Haven’t tried it yet, am going to use it to seal differential where tubes are inserted on my MH front axle.

 

I see many things that are waterproof , acid proof , etc.

 

I've used this, it works ok. The RTV I posted is better, IMO.

 

Good to know!

 

JMHO.. any silicon in the fuel system... and a weekend ruined..
Good Luck

 

I have used a goop that is usually used on steam and chemical fittings, called "Stag". It hardens, but not rock hard, and has finally sealed the gasket on my fuel sender unit. There should be an equivalent available up north.

 

Henry, have used the permatex sealer on several sending unit/ pick-up tube cork seals , after a couple years still holding, smear it on both sides, let it set up for 24 hours before filling tank.It appears identical to some hylomar I still have .

 

I use sealing washer on the screws, like GM did....

 

I started throwing the rubber gaskets that come with sending units out and making my own with the screw holes punched a size smaller so the screws have to be "screwed" through the gasket. no sealer and no comebacks.
the sealer I would use would be "aviation gasket sealer".

 

I've used kits like this on my tank, gasket and bolts with o ring seals.
https://www.tanksinc.com/index.cfm/...ct_id=646/category_id=-1/mode=prod/prd646.htm