Gas tank sealing newbie ?

I am in process of getting my 72 roadster which has sat undisturbed for 18 years going again, a friend that I should get the tank sealed with Caswells, some sort of sealant as current gas mixtures might dissolve the fiberglass tank. The tank looks fine apart from one frozen petcock. Any thoughts on the necessity of this, the tank does not currently leak. Thanks, there will be many more questions I am certain. Cheers, John

Welcome John. type 'Caswell's' or 'sealing tank' in the search box in the upper right and you will have about 3 days of reading. Good luck. I personally use avgas in my f/g tank to avoid the issue.

Dave
69S

Search google to find the forum pages and pages on the horror stories and let downs of any sealing against NWO boozed gasoline. There are like 3 recommended sealers that get mentioned. The oldest well tested fiber glass tank is my buddy Wes's tiny HyRyder tank that has THICK, like a pint+ worth of Castwells in there, 8 yr now ok.
Second test tank so far so good my IS fiber tank but only used ethanol gas for couple yrs and left mix of gasoline's sit up 3+ yr in it before dumped to paint 4 yr ago. interior prep is critical it seems. In steel tank I'd metal stuff shake with phos acid, if fiber I'd wash acetone around inside for a few min. then days of hair drier or real summer sun to fully dry out before coating a couple times rather thickly then let set up and warm up rather well before fueling.

There are many good products out there. Pors, Caswells, Hirsch to mention a few. All have been used with success and failure. Preparation is the key. Cleaning, etching, conditioning and whatever else instructions dictate is totally and completely necessary for success. Patience and no shortcuts.

I have used the Hirsch product on a fiberglass and steel tank and both are successes. I am sure that I would have done well with other products as well.

pvisseriii said:

There are many good products out there. Pors, Caswells, Hirsch to mention a few. All have been used with success and failure. Preparation is the key. Cleaning, etching, conditioning and whatever else instructions dictate is totally and completely necessary for success. Patience and no shortcuts.

I have used the Hirsch product on a fiberglass and steel tank and both are successes. I am sure that I would have done well with other products as well.

Click to expand...

por15 should not be classified with sealers that work... see fixing-fiberglass-tank-t6227.html?hilit=fiberglass%20fixing

Jean

POR 15 Does NOT work in Fibreglass tanks, new or old. In my opinion it is expensive rubbish. I have used Hirsch with success. I would still suggest not leaving fuel in a glass tank when it's not being used. Graeme

PS, other POR 15 paints are very good.

I have used POR 15 in several steel tanks. I would never use it in a fiberglass tank. One is going on ten years, the others are closing in on 5. No problems whatsoever - they look as good as the day I finished them. If it's "rubbish", well, you learn a lot on these forums. As much as I hestitated to jump in on a tank sealing thread, I only use tank sealers to provide a coating on the inside of the tank, not to fix any leaks. BMW and Harley both coated the inside of their steel tanks in years gone by. I was always amazed how good some of those tanks looked after many years. That's the reason I use this stuff, no other. Keeps rust from forming, especially on the top surface of the tank. I live in an area with high humidity, and that's a problem. I also know that if I have to weld any of these tanks, I'll just go to the radiator shop and get them boiled out, and start over on paint, etc.