Forum Discussion

turbojimmy's avatar
turbojimmy
Explorer
Aug 13, 2017

Black tank repair?

Hi all -

My Allegro was starting to sink a bit so I pulled it out of its parking spot to reposition the ramps. I have pretty tall ramps in the back, but I didn't think they were tall enough to contact the black tank which is directly behind the left rear wheel. Maybe they're not - I don't know. In any event my black tank has a sizable crack in it and it's leaking. I never noticed before, but it had been repaired in the very spot it is now leaking. It's never leaked before so I must have aggravated that repair somehow.

Anyway I see there are plastic tank repair kits available. Has anyone used them and/or have recommendations?

EDIT: I put it back in its spot and leveled it and it's still leaking. It wasn't leaking before so something happened when I moved it just now. It wasn't the ramps - there's no way they'd reach it. I don't even see any signs of new damage to the tank. But whatever, I have a problem now.

Thanks!
Class A
  • MWJones's avatar
    MWJones
    Explorer
    Aug 13, 2017
    turbojimmy,
    On the plasti-mend.com site they have a repair kit for ABS for 39.95. I have used one of these kits myself with very good results.
    Be sure to use a repair kit for ABS.
    Poly or fiberglass WILL NOT WORK on ABS.
    Good luck.
  • time2roll's avatar
    time2roll
    Nomad
    Aug 13, 2017
    I can't see or touch the damage but if silicone held up pretty good you may only need to apply a few coats of the solvent mix itself and pass on the ABS cover. It was a PITN to get mine to fit just right and get solvent applied etc all at once. If you have a helper that part would go easier.
  • turbojimmy's avatar
    turbojimmy
    Explorer
    Aug 13, 2017
    time2roll wrote:
    Black is probably ABS. Poly is usually white.

    ABS is same as black waste pipes used in homes and is bonded with a solvent that temporarily softens the surface of the plastic so the two surfaces can bond.

    I recommend a sheet of thin ABS to cover the entire crack in one piece. If it goes around a curve you can form the sheet with a heat gun. Clean and sand the area per instructions and glue the patch on. Silicone can be an issue so do not short cut the cleaning and preparation of the area.

    http://www.plasti-mend.com/cart/index.php?route=product/category&path=59
    (also check amazon)

    ABS sheet


    Great info. Thanks! I checked out their "Identifying your Plastic" link. I'm sure the tank is ABS based on their description and photos. I'm definitely going to go that route. The repair will have to bend, but I have a heat gun that I can use to form the curve.
  • time2roll's avatar
    time2roll
    Nomad
    Aug 13, 2017
    Black is probably ABS. Poly is usually white.

    ABS is same as black waste pipes used in homes and is bonded with a solvent that temporarily softens the surface of the plastic so the two surfaces can bond.

    I recommend a sheet of thin ABS to cover the entire crack in one piece. If it goes around a curve you can form the sheet with a heat gun. Clean and sand the area per instructions and glue the patch on. Silicone can be an issue so do not short cut the cleaning and preparation of the area.

    http://www.plasti-mend.com/cart/index.php?route=product/category&path=59
    (also check amazon)

    ABS sheet
  • turbojimmy's avatar
    turbojimmy
    Explorer
    Aug 13, 2017
    time2roll wrote:
    ABS? I have used and recommend Plasi-Mend.
    Polypropylene? Probably needs welded by a pro.


    I don't know what it is. It's black if that means anything. How can I tell?
  • turbojimmy's avatar
    turbojimmy
    Explorer
    Aug 13, 2017
    MrWizard wrote:
    i think you will need to empty the tank for the repair
    the sooner the better
    will probably need to let the tank dry
    and clean out the crack, before attempting the repair


    Yes you're probably right. All I had in it was a bit of fresh water and a sanitizer tab. It's already emptied itself. The crack is a big one and runs up the side - but I can get at it. It was all gooped up with silicone. I'm surprised that it didn't leak until now and also that I didn't notice it until now.

    I see Permatex makes a kit with a 2" x 4" piece of fiberglass and some epoxy. It has decent reviews on Amazon. I'd need 2 or 3 of them at $12 a pop but it's better than replacing the tank. I don't know if I could even replace it anyway. It looks easy to get out but it's 33 years old.
  • time2roll's avatar
    time2roll
    Nomad
    Aug 13, 2017
    ABS? I have used and recommend Plasi-Mend.
    Polypropylene? Probably needs welded by a pro.
  • MrWizard's avatar
    MrWizard
    Moderator
    Aug 13, 2017
    i think you will need to empty the tank for the repair
    the sooner the better
    will probably need to let the tank dry
    and clean out the crack, before attempting the repair

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