Gas tank

[454MRW]

One of the biggest problems with 2-stroke premix tanks is that the fiberglass has already been saturated by premix oil and it's almost impossible to get that oil out of the fiberglass before coating the tank. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico

[brian kirby]

quote:Originally posted by Mick Milakovic

So, if a tank and has been treated and the sealer begins to flake off, what is the fix?  I believe someone here was going to cut the tank open, clean it out, then basically rebuild the tank?  I would like to hear a step-by-step process if that is the case.

Mick

That was me. I have 6 tanks with failed Caswell coating. They are worthless as is so I figure I have nothing to lose by cutting them apart and fixing them correctly. All of my tanks were meticulously cleaned and prepped, and great care was taken applying the Caswell. All failed in 3 years or less.

Brian

[Mick Milakovic]

Brian,I have an MX tank in similar condition.  Let's talk about the process at the RR.

Mick

[brian kirby]

Sure thing Mick. There is nothing wrong with the Caswell coating, it's nothing but thin epoxy resin, the problem is you can't get the inside of the tank clean enough and even more importantly you can't properly prep the inside surface of the tank, rolling around some sheet rock screws is not enough. I did a lot of fiberglass repair on jet ski hulls and if you tried to stick Caswell to the hull of a ski without sanding it its not going to stick to that either. The only way to permanently fix it is to cut the tank open so you can prep the surface correctly. After that I plan to lay a thin layer of glass cloth with epoxy resin on the inside of the two halves, then clamp them together. Before the resin cures I will pour in some more resin to seal everything. This should be a permanent fix because epoxy is impervious to fuel, oil and ethanol.

Brian

[ccmnova]

Just having the problem of a failed caswell (or some kind of) tank sealer and have spent some time trying to get it all out of my 74 MX fiberglass tank - got most of it with wire brushes, old hacksaw blades, hangers with various end hooks, etc etc.  I got up at least 4 or 5 full dustpans of the old failed liner chips and pieces. Trying to find a replacement tank is just not possible - none to be found. I put a piece of the old liner in a cup of acetone for an hour or so - didn't do anything to it - was still hard and brittle, so I don't believe flushing the tank with acetone will do any good (and its harmful to the fiberglass.  I'm  going to clean the tank out as best I can, and only use non ethanol gas since the ethanol also will eventually break down the fiberglass resin. As far as epoxies go, the newest are phenol novolac which can stand up to ethanol.

[ccmnova]

After a couple of weeks of cleaning the tank with hangers, bent brushes, shaking screws in the tank, etc - most all of the epoxy coating is gone.  What liner is left is well adhered to the fiberglass. I flushed the tank with gas a couple of times and it seems good. I'll be sure to go through a couple of fuel filters and am using 90 octane ethanol free fuel from a local marina.

[ccmnova]

also looking for a new tank - if anyone has one please let me know.

[Carl Hill]

I have a nice one. I can send some photos, what is your email or phone number?

[ccmnova]

pls send some pics to [email protected]

[scott brogan]

Its a freak thing for sure, but I just recently bought a barn fresh 74 Berkshire that's been sitting in a friends barn for at least thirty years with out being touched. when I got it home and took off gas cap there is still gas in it. And the inside looks very good. And gas still smells like gas, but no I have not tried to start it yet.

[ccmnova]

Is that a fiberglass tank on that Berkshire ?  I bought the fiberglass from Carl Hill and it looks good -

[Larry Perkins]

Yes a 74 Berkshire had a fiberglass tank.

Larry P

[ccmnova]

Well the gas sitting in the tank sure didn't bother that one !  I'm being told not to leave even non Ethanol fuel sit in the fiberglass tank for any length of time.

[Larry Perkins]

It is the ethanol gas that screws them up.  It softens and thins the glass.

Larry P

[Carl Hill]

Never ever put ethanol in a fiberglass tank. Race gas is expensive but well worth it.