Marbles Motors failed gas tank liner, then screwed up the warranty repair!

One thing I have heard about the Caswell is if you get a small ding in the tank or hit an edge it can crack the liner and start problems. Also large temp swings, say your tank is stored in a garage that can get into the 90's in summer and single digits in winter. The liner does not have enough flexibility and may crack. Any thought on these scenarios. These were examples from reading comments on the internet (so they must be true)LOL
 
One thing I have heard about the Caswell is if you get a small ding in the tank or hit an edge it can crack the liner and start problems. Also large temp swings, say your tank is stored in a garage that can get into the 90's in summer and single digits in winter. The liner does not have enough flexibility and may crack. Any thought on these scenarios. These were examples from reading comments on the internet (so they must be true)LOL
I put Caswell in a 650 Special I turned over to my daughter. It lives in a tight shed in the back yard in Atlanta. My cousin lined a couple of tanks with it and uses the bikes. He's parked in the basement and lives in Atlanta, so not a good test, either.
 
I’m going to add this here, just because this guy does such beautiful work. Pricey but beautiful.

http://gastanklining.com/index.html

I just wanted to be clear, this is not the company that is re lining my tank. I just came across them online and thought their work was impressive. Plus he has a great tutorial video on how to pack and ship a gas tank. Which I
(mostly ) followed.,
 
I just wanted to be clear, this is not the company that is re lining my tank. I just came across them online and thought their work was impressive. Plus he has a great tutorial video on how to pack and ship a gas tank. Which I
(mostly ) followed.,
Since you hired professionals, I believe you are correct in leaving the job to them. They're backing it, they should handle it.
 
The tank that came with my bike, I sent to a professional tank restoration company. They specialise in tanks for very old bikes - flat tanks, that sort of thing.

But their professional opinion was my XS tank not worth the cost for them to deal with because the rust was coming through from both sides. Makes me think that no matter how good a job is done of preparing the inside and lining with epoxy or whatever you will still have a problem if rust comes through from the outside. Not saying that's necessarily what has happened with Mailman's tank.
 
For corrosion to happen, there has to be an electrolyte present. Without it, no rust. So, if the paint completely protects the metal on the outside and the tank liner completely protects the inside, no rusting is going to take place. @Mailman's tank would not have rusted if the liner had done what it was supposed to do. That rust was caused by an electrolyte getting behind the liner.
 
My sample is fairly small but I think there may have been issues with the steel used in some 72 tanks............

The rust that was inside my tank when I bought it was significant. It was very scaly and loose and the metal was pitted. It simply had to be lined. I really don’t know exactly what liner was installed, but as Jim and Marty have suggested, I think the root of the problem was bad preparation.
This is what it looked like to begin with, but the worst of it was towards the bottom.
06A0A305-1D1D-4862-AF77-D71AF84C018A.jpeg
 
Steel, which is about 99% iron needs moisture and oxygen to form rust. Take away either and you stop the rust. The problem with poor prep is that the rust that's still in the tank is porous. Just like a sponge will hold water and oxygen, so will rust. If you cover that with epoxy (the liner), what you're doing is trapping the elements required for the rusting to continue. So, the rust pushes against the liner, breaking it loose and cracking it, allowing more oxygen and water in. All poor prep did was delay the inevitable.
 
The rust that was inside my tank when I bought it was significant. It was very scaly and loose and the metal was pitted. It simply had to be lined. I really don’t know exactly what liner was installed, but as Jim and Marty have suggested, I think the root of the problem was bad preparation.
This is what it looked like to begin with, but the worst of it was towards the bottom.
View attachment 175677
Sorry to see the troubles you are having with your tank.
When I got my XS2 out of storage after 35+ years my tank looked far worse than that. I could see rust everywhere in it. The bottom was a half inch thick with the remnants of old gas and rust. I spent months cleaning it. Started with putting some gas in it, letting it soak into the crap on the bottom. Then added some rocks and shook the heck out of it. When I dumped it chunks of crap the size of Snicker Bars came out. Next was water and more rocks. Shake rinse repeat several times until no more big chunkys. After that used 1/4 20 nuts in place of rocks. Shake rinse repeat a few more times. Rinsed it out real well. I had gotten the big chunkys out but the inside still had rust. Next was a White Vinegar fill and soak for a week. More rinsing. Looked better. Still some rust.I had read about phosphoric acid. Used that in it. Better, but not perfect. I wanted to use it on my bike so I rinsed it till I thought I had all the loose rust out. Dried it out on the inside, rinsed it with alcohol and then rinsed it with gas. Put it on the bike and have been using it ever since. I will admit it was not perfect. I had some rust still in it. Enough it plugged up a set of fuel filters. As time and miles have gone by the amount of rust coming out has gone down to almost nothing. As I said I spent months on and off working on it. Between times of working on it I would dry it out inside.
As you can see it's not perfect. I don't think the rust that I can see is new rust. As Jim said in order for steel to rust it needs moisture and oxygen. As Gary said gasohol does have the ability to absorb moisture. In the great state of Illinois it's hard to find real gas. My bikes get a steady diet of gasohol.
I've read all the threads about de-rusting tanks. This winter I may try to get it better. Sealer would be my last resort.
upload_2020-9-19_11-47-0.png

upload_2020-9-19_11-48-49.png
 
Never heard of Caswell. Sounds interesting.

I don't advocate liners because of the difficulty in prep and inconsistent results. Including having the liner peel and flake off bad enough to clog the petcock!

The factory left the tank bare steel and it worked for decades, good enough for me!

The time spent on prep usually will exceed the price of a good used tank.

650s aren't rare so we don't need to use the
"Save it by any means necessary" approach.
 
The way to ship a tank via the video you posted makes me wonder why Yamaha sent new tanks in a box the size of the tank. It was almost
a double box with extra cardboard pieces all around the tank was in a plastic wrap. No bubble wrap...I don't think it was invented yet. I never opened a boxed tank from them that had any blemishes or scratches or dents. This was during the '70s when I worked at a dealership.
Good luck with the warranty work on your tank Bob. Did you ask them to not paint around the petcocks?
 
Did you ask them to not paint around the petcocks?

No, I didn’t want to push the guy. I was shocked he offered to re do the tank at all.
The first time they painted the tank, the petcock holes were filled with tank liner and paint, and I expect they will be again. I plan on removing the paint under the petcocks myself when I get it back.
 
Sorry to see the troubles you are having with your tank.
When I got my XS2 out of storage after 35+ years my tank looked far worse than that. I could see rust everywhere in it. The bottom was a half inch thick with the remnants of old gas and rust. I spent months cleaning it. Started with putting some gas in it, letting it soak into the crap on the bottom. Then added some rocks and shook the heck out of it. When I dumped it chunks of crap the size of Snicker Bars came out. Next was water and more rocks. Shake rinse repeat several times until no more big chunkys. After that used 1/4 20 nuts in place of rocks. Shake rinse repeat a few more times. Rinsed it out real well. I had gotten the big chunkys out but the inside still had rust. Next was a White Vinegar fill and soak for a week. More rinsing. Looked better. Still some rust.I had read about phosphoric acid. Used that in it. Better, but not perfect. I wanted to use it on my bike so I rinsed it till I thought I had all the loose rust out. Dried it out on the inside, rinsed it with alcohol and then rinsed it with gas. Put it on the bike and have been using it ever since. I will admit it was not perfect. I had some rust still in it. Enough it plugged up a set of fuel filters. As time and miles have gone by the amount of rust coming out has gone down to almost nothing. As I said I spent months on and off working on it. Between times of working on it I would dry it out inside.
As you can see it's not perfect. I don't think the rust that I can see is new rust. As Jim said in order for steel to rust it needs moisture and oxygen. As Gary said gasohol does have the ability to absorb moisture. In the great state of Illinois it's hard to find real gas. My bikes get a steady diet of gasohol.
I've read all the threads about de-rusting tanks. This winter I may try to get it better. Sealer would be my last resort.
View attachment 175684
View attachment 175685

Id be thrilled if my tank looked that good!
 
Wow Bob - that rust looks pretty serious indeed.

FWIW - I did a fair bit of research on this when I got Lucille in the winter of 2016 and her tank was a mess inside. My investigations revealed that POR-15 is well regarded (Jay Leno uses it on his multi-million dollar cars) and so I went with that. As I recall it, the process has four distinct steps:
  1. Cleaning - with a powerful de-rusting agent. I don't know what it was, but the stuff came out looking like coffee with LOTS of chips and yuk in it;
  2. Rinsing - with plain water - until everything inside looks clean and the water comes out clear;
  3. Drying - with a heat gun shoved into the fuel hole to get rid of any trace of water;
  4. Coating - the gooey, silvery coloured liner has a consistency a bit thinner than toothpaste. The catch is that you have to keep turning the tank until it firms up (several hours) to distribute the coating evenly around the inside of the tank.
The toughest step was the last one - moving that tank around to evenly coat the inside for 3-4 hours was absolutely exhausting and my shoulders took several days to recover. Nonetheless, that tank still looks good and the POR-15 coating seems to wear like iron. Incidentally, the name POR stands for "paint-over-rust" but they do not actually advocate leaving the rust in-place. I completely agree with Jim - any product that suggests that the coating will adhere to rust better than clean metal is simply wrong.

Since I did that tank, one of my buddies has built a tank-tumbler (think portable cement mixer) and it makes the even distribution process dead easy. To clean a tank, he puts in 3-4 litres of water and a couple of hands full of aquarium gravel (nuts and bolts could also work). I think he has used it to spread tank sealer as well. Anyway, you just pour in the goo, mount the tank in the tumbler and turn it on - and walk away for a few hours / overnight - and wah-la. The XS750 tank that he tumbled for me came out looking brand new inside - although the water and gravel mix had to be changed a couple of times due to the amount of rust that was being [gently] knocked off the inside. The process was much less harsh than simply shaking the daylights out the tank - and it sure worked well (notwithstanding the problems that Jim has had painting the darned thing.

Here is a YouTube clip of a tumbler built by another guy. The one my friend built is much more robust - but works in essentially the same way.


Anyhow - this is clearly a key problem for older vehicles with metal fuel tanks and so my bet was that Leno and his people did the research and came out with an answer with which he was satisfied. Here is the video that convinced me:


Pete
 
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Jay Leno as gospel......... Well there is the whole paid sponsors thing.:unsure:
Wandered around the whole gas tank "shaker/stirrer" idea few times but never got to the gathering parts phase.
 
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