1971 Build for Dad

I am thinking of draining it and switching to paint stripper as Marty suggested or some other nasty chemical (the benefits of running a laboratory :sneaky:).
If you read what I put in the other forum you'll note that the paint stripper didn't work for me and made a mess (YMMV).

Once the acetone had done its job, I drained the tank and let it dry. I removed the residue mechanically with resin blocks from Harbor Freight.
 
but at least you're not trying to salvage a good paint job in addition to cleaning out the insides.
I am very thankful for that! The outside of this has definitely taken a chemical beating throughout this process.

I did a half dozen acetone washes today (reusing the acetone a few times after straining out the liner chunks). I would say I have greater than 95% of it out. What's left just isn't going to come... I was planning on lining this tank with POR 15, but after this nightmare I think I am going to try it without a liner. It's not leaking acetone, so I doubt it will leak gas. Can always go back and line it later, if needed. Sound reasonable?

Also, thoughts on what to put in there to stop flash rust? Slosh some motor oil around in there? Have heard of quite a few recipes, but never tried any..
 
Also, thoughts on what to put in there to stop flash rust? Slosh some motor oil around in there? Have heard of quite a few recipes, but never tried any..
Haven't done it in ages, but here's my old recipe.... Take 1 to 1 1/2 pints of acetone. Dissolve into that 2 or 3 heaping tablespoons of general purpose grease. Slosh it around the inside and drain off the excess. Use a blow gun at about 5-10 lbs of pressure and tape it to the filler hole.... leaving it open so it can "breathe." This will evaporate the acetone, leaving a thin coating of grease inside the tank. It'll last for years in storage like that.
 
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My only hesitation to not lining it again would be why the previous owner lined it to begin with? Are there any signs of pitting where the old liner came off? I've had really great success with por-15 on three tanks.
 
Also, thoughts on what to put in there to stop flash rust? Slosh some motor oil around in there? Have heard of quite a few recipes, but never tried any..

After I I de rusted my gas tank, I mixed a little acetone with motor oil and sloshed it around inside. The acetone flashes off , leaving an oil coating. Idea courtesy of @Jim , it worked very well.
Edit: Ha! Jim beat me to it!
 
Are there any signs of pitting where the old liner came off?
Not really, it looks pretty good. I should say that I am hesitant to not line it. I like the idea of lining gas tanks... When you think about it, it is insane to try and keep hygroscopic fuel in a rust-prone vessel! I even have the POR 15.. What gets me are the tiny little bits of liner I can't get off. I am worried the liner won't adhere to that or will slough off and take the rest of the liner with it. As is, worst case I would just get a clogged fuel filter. The liner looks just like red RTV as it comes off. You think the liner would cover it ok?
 
Have you tried sloshing an abrasive around inside?
Yep. Have been using 75 of these thread inserts. They are fairly heavy and have sharp threads. I think they are a big reason as to why I have been able to get most of it out.

My wife would kill me if I put a gas tank in the dryer!! :gun:
 

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You think the liner would cover it ok?
I don't know as all the tanks I've lined didn't have any previous lining (or remnants therof). Just had to derust first. That said, POR 15 seems to stick to everything. I still have a glob that spilled on one of my boots over two years ago that I didn't notice until the next day. Still there and I can't scrape it off for nothing :rolleyes:.
 
Women just don’t understand. :shrug:
Yep. Funny how when they break a jar of nail polish on the tile it is no big deal. And let me tell ya, that DOES NOT come off of grout.

I have some decisions to make... going to do another acetone wash and ponder it... Thanks all for the feedback!
 
Hard to know why it was lined in the first place. Could be that it was done years ago as insurance on a new paint job and didn't really need it. So if there are no leaks, I would run it as is...make sure to add in-line filters. Going back to my previous post, I despise liners and if possible, avoid them. However, if there are leaks, and you can't braze them, then a liner may be the only option.

My method To prep the tank for storage and to keep it from rusting just after cleaning out with evaporust or whatever de-rust mixture used, I'II rinse the entire tank with water, drain as much as possible, then pour in a cup or two of acetone (or denatured alcohol) and drain...this seems to help get the remaining water out. Moving quickly, I blow a little compressed air, use a heat gun to warm up the tank and help evaporate things faster...and then I mist WD40 all over the insides. I have a tank right now sitting on a shelf that's still rust free 3 yrs later. I use WD40 since I can spray it and it mists up covering everything...but after reading Jim's process, I like the idea of acetone mixed with oil (I'd probably use 2 stroke oil), seems like a solid idea and saves a step.

If you have to add a liner, as I mentioned, I bought Por-15 and was going to go that route on my current tank project. I have heard great reviews...but with a failed liner, Caswell's states that it works on/over failed liners including Por-15, and I also heard great reviews about it. I like the 2 part epoxy concept...so that's the route I took.
 
I bought Por-15 and was going to go that route on my current tank project. I have heard great reviews...but with a failed liner, Caswell's states that it works on/over failed liners including Por-15, and I also heard great reviews about it. I like the 2 part epoxy concept...so that's the route I took.
I like the epoxy approach, as well. In any form, epoxy is a tough substance. Truth be told, I tried to return my POR-15 in exchange for Caswell, but Amazon doesn't accept hazardous chemical returns!

Plan to mess around with the tank today and see what I can get figured out. While I don't see any leaks, there is some brazing on the bottom seam I discovered. Makes me nervous... Acetone is so volatile it might be flashing off before I can notice a small leak... Going to try an organic solvent that you can't get at your local hardware :sneaky: and see where that gets me. Ideally, I can get all of the liner off and use the POR. If I can't, I might have to bite the bullet and go with Caswell.
 
Ya, I was guessing. All I know is that it wasn't more than a couple of pumps on my bike pump before the cork I used to plug the filler hole popped off. :)
 
I have been chipping away at this tank all week. Firstly, my initial estimate of having removed 95% of the old liner was way off :doh:. WAY in the back of the tank there were huge clots of the stuff. It took my straight methylene chloride and this janky homemade brush to get most of it out.

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I continued to shake the tank with a variety of abrasives and solvents, each time with small amounts of the liner coming out. I finally decided that I would probably never get all of it out... I also used the soapy water trick to find a small leak in the bottom seam of the tank. These two factors drove me to purchase the Caswell epoxy liner.

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This was a messy job, this epoxy sticks to EVERYTHING, but I am over the moon with the results. Was very careful to dry the tank with denatured alcohol and a heat gun prior to sealing it. It went on easy and by the time it cured all the bubbles had popped and it was mirror smooth and looks tough as nails. Case closed on the interior of the tank!

Moving forward - body work... I plan to do the original tank first for practice. It is in much worse shape and has a liner of unknown quality, but I am still going to at least get the bodywork done and prime it to stop any further corrosion. That being said, I felt even better about switching tanks, as the original one had some serious rust and pitting under the paint. I am going to try and solder some of the deep holes that look like wood boring beetles got into it. Will keep you posted!

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