1982 Porsche 928 - Gas leak

I have a 1982 Porsche 928 with small slit in gas tank dose anyone know what type of plastic the tank is made of?
Thanks for any help

Porsche 928: How to Fix a Leaking Gas Tank | Rennlist

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Thanks do you know what type of plastic the than is made of?

Typically plastic fuel tanks are made of cross-linked polyethylene.

Why do you need to know this?

Because he’s a Porsche owner :laughing:

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I have a slit in the fuel tank of 1982 Porsch and was advised there are some plastic weld products like

I just put ( Plastic fuel tank repair ) in Google . Got several hits and it seems NAPA has a kit just for this purpose . It also says ’ not vehicle specific ’ . So it appears you are making this too complicated. Or call around and find a shop that will do this for you where ever you are.

I suggest you not do this yourself. Repairing fuel tanks can cause instant explosive death if you do not know what you are doing.


If it is cross linked polyethylene (PEX), it can be repaired with epoxy or another structural potting compound. Any adhesive that adheres to polyethylene is fine, you aren’t going to heat it to cross link it anyway. You might consider drilling holes at both ends of the crack to prevent crack growth, then apply the adhesive. If it sags, just put a piece of tape over it to keep it from sagging. I think surface preparation is the most important issue. If the surface inside the crack isn’t prepared properly, the adhesive won’t stick. That might be a good reason to have it repaired professionally.

I’d post this question on a 928 forum for additional answers. They probably already have several discussions on the topic.


I just wanted to make absolutely sure this poster did not consider welding the crack with any flame producing device in any way!

A cold repair is the best bet… and @weekend-warrior posted that link in the first response, yet the OP persisted in requesting the material spec. That concerned me.


Because he drives an expensive car and doesn’t intend to spend the money to have the tank replaced.


they are probably hard to find new and maybe even used.


PLASTICS TECHNOLOGY. High-density polyethylene (HDPE) has been the resin of choice for plastic gas tanks, and production capacity has been on the increase.


Thanks I am hoping to find an epoxy compound I can use but so far most I,ve found state they won’t work on Polyethylene. I talked to a tech at JB Weld and was told that their plastic weld would work if i wasn’t using ethanol gas but I’m still unsure. Am looking for any and all suggestions

Well , why not just replace the fuel tank and be done with it . If your repair fails a fire will be in your future . A fuel cell in the trunk is another option.

Edit: Have you even done any Google seaches ? It seems there are videos showing how people have repaired plastic tanks .

Thanks for all the responses. I am not going to do the plastic weld if I can find an epoxy that will work has anyone else out there had any experience with this? I’ve also been recommended I try Blue magic 6522KTRI anyone used this?
I also live in a rural area (Northern Neck VA) which makes finding things a challenge at times

I would empty the tank, remove it, and take it to someone who does plastic welding. I live in a rural area so there are lots of plastic tanks used by farmers, and there is a place that specializes in plastic welding. Perhaps your area also has someone.


I knew it!!

That makes no sense. If the tank can accept ethanol fuel, the weld is the same material - that is what plastic welding is - so why would the tank not accept it after a repair?