Caswell liner failure

[willis]

Shit, shit, triple shit!!! Today I was putting the bikes into winter storage. I drained the fuel from my ‘75 and peeked inside the tank and noticed something did not look right. Upon closer inspection I found that my Caswell tank liner has failed. It just makes me sick. This tank was professionally painted and sealed. When I bought the tank, it had been painted seven years prior and never installed or had gas in it. I’ve had it for roughly 2 years now. The liner looked fantastic when I got it. It is clear now that the liner is separating and breaking apart. The metal inside the tank looks very nice with no rust I can see. It’s very hard to get pictures in there but these show the worst part. I am not sure how to go about removing this liner. All I have read indicates using nasty paint stripper. I’m so afraid it’s going to ruin this beautiful paint job. I’ll have to reach out to Caswell for their recommendations. I don’t think the MEK I’ve heard of is available anymore.

 

[jetmechmarty]

MEK is available at my local True Value Hardware. This is the first I've heard of Caswell failure. I hope that isn't a sign of things to come for me.
This LINK covers my experience removing a failed fuel tank liner from a tank with a new paint job. I tried paint stripper then acetone. I did it without hurting the paint.
https://xs650temp.proboards.com/thread/17274/failed-tank-liner

 

[Mailman]

Man, I’m sorry to hear this Rob. Yeah, MEK is the way I always heard of. There’s always this company if you don’t want to try it yourself,

http://gastanklining.com/

Not cheap, but quality work.

 

[Paul Sutton]

I would be inclined to leave the liner until I where forced to do something about it...

 

[Kevin Werner]

Fill half way with limestone chips (peastone) and shake it up. Would this work?

 

[willis]

The weird thing is that the liner that has lifted is brittle. When I was probing around with a thin metal rod, I was able to poke through like it was this plexiglass. I was also able to see gas underneath it when pressing with my probe. It’s like it shrank. Weird. I have a weird feeling of Dejavu Bob after thinking back to your tank thread. Fortunately this bike was not really ran this summer. I’m hopeful not to have the same experience that you did with your motor and carbs.

 

[jetmechmarty]

I would be inclined to leave the liner until I where forced to do something about it...

Those pieces could block fuel flow. What if it's dissolving?

 

[willis]

Caswell is an epoxy liner. It’s going to require some harsh chemicals to get it out. But hopefully since it is lifting that may help in removal if the chemicals can get under it.

 

[ThatXS650Guy]

That's not good. Also the first failure I've ever seen of a Caswell lining. Hell, there's a big splotch on my garage floor from three years ago.

 

[willis]

Just a thought, if the ethanol is causing it to fail, what’s the harm in using a stronger ethanol mix to remove it? Hopefully some of you more smarter guys than me can provide your Lol. Would pure ethanol be harmful to my paint?

 

[Mailman]

I have a weird feeling of Dejavu Bob after thinking back to your tank thread.

Yours looks like it’s brittle and flaking off. Mine was way worse it was melting, the surface felt tacky and sticky and that’s what ruined my motor. It was inside everything, my carburetors, intake tract, valve train, cylinder bores, and the piston rings were stuck.

 

[grizld1]

I've lined four tanks with Caswell over the years and never had an issue, and in my area we've had only 10% ethanol fuel available for over 20 years, except for a brief period from 1918 to 2020 when one station offered alkie free gas. If the liner isn't just a bit soft and squishy, I doubt that alcohol is to blame, and I very much doubt that it would dissolve the epoxy for removal. Could the installer's surface prep be part of the problem? If there was a spot where the epoxy failed to bond, that could have started the lifting. I flush the tank with high pressure water at a car wash, then fill it with a nasty 50-50 mix of acetone and denatured alcohol and let it sit for a day or two, to eliminate any fuel residue and improve adhesion.

 

[willis]

The painter is a well know guy that’s been around a long time. He does high quality restoration jobs. He nailed my star black job with the right amount of silver flake. In fact, I took him my side covers to have him match them to the tank that he painted seven years prior. The liner looked fantastic when I installed it and before i added fuel. So this damage has occurred in the last 2 years while sitting with fuel in it. I am shocked to have found it in this condition today. I cannot say for sure that his prep was spot on, but from the quality of his work and what I saw when I bought it I would not have guessed this would have happened.

 

[Kevin Werner]

There have been cases of chemical suppliers providing the wrong mix or a mix with wrong ratios of components.

 

[GLJ]

The painter is a well know guy that’s been around a long time. He does high quality restoration jobs.

If you can you might want to take it to him as see what he thinks. Don't go in with the attitude that he did anything wrong, 7 years is a long time. He may be very interested in your problem. I would bet he will at the least advise you with the best way to fix it. It's also to his benefit to figure out what went wrong.

 

[gggGary]

So sorry @willis
Following, cuz I gotta tank with a failed liner. yeah our local Menards has MEK, I have a quart but would need a couple gallons. Scary stuff to use.

 

[willis]

He’s located 2hrs away. I certainly do not think this was negligence on his part by any means. As a reminder, I did not pay him to paint it. I bought it on eBay from the person that did. This was sealed 9-10 years ago. I’m sure a lot has changed over that time. Fuel chemistry, sealer chemistry… etc.

 

[JRay77]

My thoughts on tank liners….I don’t know the answer. I’ve researched and researched. Metal prep is crucial. I’ve still had one fail doing it to the directions. Kreme, not a fan. POR 15 not, a fan. Gold Seal, not a fan. One kit had a degreaser and zinc etching step. I did these and then used the red stuff. I’m still waiting on this to fail. It’s been two years. I still have slightly tinted red gas. Seems to run ok. The only full proof tank? Plastic or aluminum. I’m thinking about propane here lately too.

 

[willis]

I’m going to probe around that tank a little more tomorrow. Try and get a better look at the rest if it.

 

[gggGary]

Get a couple of the loose chunks, immerse in your candidate solvents, see what they do to the samples.
That's my next step.