85 L plastic gas tank disaster

[gulf908]

I have recently had to put down my plastic gas tank due to too many leaks and not enough effective repair material.
The tank has only been in my car since early last year and came from a parts car that had been sitting for an indeterminate length of time in the back of someone's workshop.
My mechanics have tried to stop the leaks but as soon as one was fixed another one appeared a short time later until they said it was a losing battle and the tank was terminal.
At a recent 356 day in Melbourne I checked out Hugh H's original '73plastic tank and it looked in a very much better condition to mine.
I concluded that the tanks should be in use continually and not left to sit around to dry out terminally as mine has done.
Needless to say,this has been an expensive excercise to junk the tank.
? is this not uncommon for these tanks to dry out after a period of un-use or was I just unlucky in this particular tank ?
Over to the plastic gas tank experts,please !

Cheers,
Dennis

[HughH]

Hi Dennis

sorry to hear about the tank

did you try putting a bladder or some other sort of liner inside it like a modern fuel cell?

[peekaboo]

Hi,

If your taking about small holes. I can't believe a product like Por15 gas tank sealer .

Or some other similar product would not cure it ?

You prep. (on metal tanks : remove any loose scale , by throwing some bolts / nuts into the tank and agitating) . Depending on how solid or not solid your tank is. You can also use a low power acid wash at the same time, if it's too rusty this could create more problems however (if you do the acid wash , be careful hot to breath fumes. Work in good ventilated area with fan going).

Then pour in the sealer coating and manipulate so you get a complete inside surface covering. Then it drys.

I would think it would also work / adhear to plastic ? If this product wouldn't . I can almost garrantee that there is a product made somewhere by someone. The problem is just figuring out the correct product. I've found that with chemically manufactured type products. There are actually all kinds of killer products made, just most people don't know of them. As unfortunately now , we live in a throw away / replace mentality world. So the info. just does not get circulated. A similar example is when I just recently wanted to seal a pin hole in a rubber piece. When I was reseaching 'cold vulcanising compound' , i found all kinds of great sealing products in the industrial manufacturing sector, for use on all kinds of surface materials.


I would not give up

[John Fusco]

Ethanol ?
Bad - very bad

Caswell is what a lot of vintage MC folk are using now.

http://www.caswellplating.com/aids/epoxygas.htm

[dave29]

I have three original "plastic" tanks sitting on the shelf. When I purchased them about 4 years ago, they had sat on a shelf in Germany for years. I pressure checked them and also filled them to check for leaks. None leaked.
I don't think they "dry out". Must be another issue with how your's was used during it's life.

[peekaboo]

Well, I had never looked at Caswell.

But from their website . States their "Epoxy Gas Tank Sealer (PHENOL NOVOLAC EPOXY GAS TANK SEALER)" .........will work on plastic.

"Permanently Repairs Steel, Aluminum, Fiberglass and Plastic Gas Tanks" , as long as it's not made of
polyethylene.

"Bonds to almost anything except polyethylene (gas tanks are not made of polyethylene). Bonds to wood, plastic, rubber, concrete, metals."

[Steve@Rennsport]

Well, I had never looked at Caswell.

But from their website . States their "Epoxy Gas Tank Sealer (PHENOL NOVOLAC EPOXY GAS TANK SEALER)" .........will work on plastic.

"Permanently Repairs Steel, Aluminum, Fiberglass and Plastic Gas Tanks" , as long as it's not made of
polyethylene.

"Bonds to almost anything except polyethylene (gas tanks are not made of polyethylene). Bonds to wood, plastic, rubber, concrete, metals."

Well sir,......many gas tanks are roto-molded from cross-linked polyethylene so you may have a problem. I would find out what those were made from before making a decision.

[andyjboy]

It might be worth contacting someone who specialises in repairing sailing dinghies - Toppers, etc are made from injection-moulded polypropylene.