1976 Penton MC5 250 Fiberglass Tank Leak

[Bryan Adams]

I have a leak on the left pet cock threaded port.

I've applied an epoxy to the tank, used gas resistant thread tape, and replaced the pet cock itself.

I contacted a guy in Kentucky that repairs fiberglass tanks, but he said he would not touch it because I used the epoxy in the tank.

Any suggestions would be much appreciated.

Bryan

[Mike Korgan]

Was it Caswell tank sealer. It worked for me on the same repair.

[Bryan Adams]

Mike,

Yes, it was Caswell.

I still have some of it, maybe I'll try another application.

Bryan

[R.T.Fischer]

Those tanks were made with polyester resin, epoxy will not form a chemical bond to polyester, so you have to create a mechanical bond by really scuffing , scratching the surface up so the epoxy has something to grab onto. That's after you really clean the surface of all residue, especially gas & oil that has soaked into it. Multiple washings with detergent & then a final clean with acetone & let dry completely. Epoxy is a very hard resin and is more gas resistant than polyester but at the same time more brittle so it needs a flexing agent added to bend more without cracking & separating. Also use non ethanol gas whenever possible.

[Mike Korgan]

I agree. I was told the prep was a critical step. Multiple washes and shaking it with drywall screws inside to rough up the surface was recommended.

[61rover]

Would you mind sharing contact info for your tank repair guy in KY?

John Crouse
74.5 Jackpiner 175