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Removing Factory Tank Liner and New Casewell

Discussion in 'Airheads' started by Gismofx, Jan 3, 2020.

  1. Gismofx

    Gismofx Adventurer

    Joined:
    Oct 27, 2018
    Oddometer:
    14
    Location:
    Florida
    My 78 R100 had a poorly repaired hole in bottom of the tank. Needless to say, it was slowly leaking. I brazed a little patch over it and that’s fixed. Next, the rust and decayed factory red liner. I decided upon casewell epoxy liner, but prepping the tank first. I tried a “safe” stripper and got nowhere. Then, went with methlyene chloride. I was expecting all the liner to be removed, but it’s still “mostly” intact. I did the sloshing around with chains in the tank and a lot of gunky liner came out, but not all.

    Does all of the old liner need to come out before casewell liner is applied. Also, I was planning to use Phosphoric Acid prior to casewell liner.

    Are there any additional steps? Any chemicals/rinses between the phosphoric acid and the casewell liner?

    Thanks!
    #1
  2. satmanski

    satmanski Sausage Creature

    Joined:
    Aug 11, 2015
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    Spokane, WA
    You will find that a lot of people have used industrial white vinegar which is available at home depot and cheap. I used the POR 15 cleaner degreaser and a big chunk of chain. Same thing, plan on leaving it in and sloshing it around. To answer your question your tank needs to be absolutely bare metal for the new liner to work. Don't get impatient. I didn't use the casewell so I can't say what steps it requires. If you have a change of heart on the casewell I can vouch for the POR15 tank liner system. Did a great job on my tank.
    #2
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  3. TwoShoes

    TwoShoes How Many Shoes?

    Joined:
    Aug 18, 2003
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    Location:
    Fredericton, New Brunswick, Canada
    Recent tread on this very subject https://advrider.com/f/threads/rust-and-old-tank-liner-removal.1413618/

    Agree that the tank needs to get to bare metal. I can also agree that the 10 % vinegar works well on the factory liner. I can also vouch for POR15, I had such good luck on that R100/7 tank that I decided to use it on the G/S tank last night with very nice results, I was even able to get it to coat the inner baffle in the big Paris Dakar tank
    IMG_4529.jpg
    #3
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  4. satmanski

    satmanski Sausage Creature

    Joined:
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    Spokane, WA

    Heck, now I want to post my 'after' photo.

    Attached Files:

    #4
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  5. Big Bamboo

    Big Bamboo Aircooled & Sunbaked Supporter

    Joined:
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    +1 on the cleaning vinegar, and it won't kill your cesspool if you dump it down the drain.
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  6. Gismofx

    Gismofx Adventurer

    Joined:
    Oct 27, 2018
    Oddometer:
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    Florida
    Thanks all for the comments!

    Seems almost unanimous regarding vinegar. So, I opted to strip the liner with 10% vinegar. 6 gallons in my tank now and will just flush it through daily(if I can). I can wait until next weekend for the results. Will report back.
    #6
  7. TwoShoes

    TwoShoes How Many Shoes?

    Joined:
    Aug 18, 2003
    Oddometer:
    476
    Location:
    Fredericton, New Brunswick, Canada
    I found the routine of (1) drain vinegar (2) shake chains around when tank is empty to loosen the bits of lining (3) refill with the vinegar

    to be useful. Good luck!
    #7
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  8. KatCon85

    KatCon85 Been here awhile

    Joined:
    May 3, 2013
    Oddometer:
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    Location:
    Hudson Vally, NY
    I did the white vinegar thing 3 years ago, and Caswell liner. It came out great. 2 things I would mention. after the vinegar and chain, rinse the tank with hot soapy water & baking soda. Then rinse it again with clear water. I used a hair dryer to completely dry the seam in the bottom of the tank. Then let it sit overnight in the house and did the caswell the next day.
    I would mix up more than you need. My kit said "does a 10 gallon tank" so I mixed up 1/2. it ended up a little short, so there was a frantic -mix up a little more - moment towards the end.
    Also, when you apply the liner- do it in a warm location (not your cold winter garage) so the epoxy liner flows a little better.
    #8
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  9. Gismofx

    Gismofx Adventurer

    Joined:
    Oct 27, 2018
    Oddometer:
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    Going well so far! Looks like most of the liner is gone! But I developed a new pin hole near the first larger hole. I’m going to pause and braze this one up and probably do another day or two of vinegar.
    #9
  10. Gismofx

    Gismofx Adventurer

    Joined:
    Oct 27, 2018
    Oddometer:
    14
    Location:
    Florida
    From what I can see all the liner is now gone!(about 1 week of vinegar soaking)
    • I flushed the vinegar about 4 times throughout the week
    • I used 5 pieces of 1ft x 1” chain in the emptied tank to help remove the liner between flushing.
    • After shaking with chains for 5-10 minutes, I removed the chains with a magnet and rinsed out the loosened liner bits with a hose
    • I refilled the tank with the same vinegar using a drill powered pump. I attempted to filter the last half gallon or so of vinegar with coffee filter.
    • After all done, I rinsed the tank clean with warm sodium bicarbonate water solution, then fresh water rinse and air dried with a blow dryer. I brought the tank inside and waited a week(busy with other things)

    I’m now beginning a phosphoric acid coating/etching.
    #10
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  11. Gismofx

    Gismofx Adventurer

    Joined:
    Oct 27, 2018
    Oddometer:
    14
    Location:
    Florida
    I did the phosphoric acid soak, wash, and dry with a blow dryer...and tank looked good. I put the tank aside to finish some other projects. Two months go by and my tank is completely flash rusted.

    I resoaked the tank with phosphoric acid and the flash rust immediately disappeared. Soaked for a day with the occasional shaking. I flushed it with a detergent and then water and then blow dry all night. It still flash rusted almost immediately.

    Is the phosphoric acid supposed to prevent flash rust?

    I have a casewell liner kit but hesitant to apply it at this time
    #11