Flex Seal repair on grey tank.

In stead of dissolving a piece of ABS sheet you can also do the same with a piece of ABS pipe or ABS fitting to make a paste.

If it is a small crack you might be able to just use ABS glue painted over the crack after cleaning if up and excavating it instead of making a paste.

Sooner Schooner wrote:
Have any of you used a Flex Seal product to repair a crack in a holding tank?

If its black it's probably ABS and if so I would get a small sheet of thin (12x12x1/16) ABS and a quart of Acetone. Cut the sheet into small bits and dissolve in the Acetone to make a fairly thin paste. Then rough up the area of the crack with 60 or 80 grit sandpaper and then wet the area with Acetone dabbing it with say a small paint brush and keep moist for about a min and then before it drys start layering of the paste you made covering the crack and about 1 inch further out until you get about a 1/4 inch layer of new ABS over the crack. This will "CHEMICALLY WELD" the area of the crack with new ABS and should give you a permanent repair. Key is once you start keep the area wet so you start dissolving the tank ABS around the crack and then apply the ABS paste and don't let things dry out until you complete layering the ABS paste over the damaged area.

Even better, but somewhat harder is to first using something like a dremel cut a "V" along the crack so you can get the paste down into the tank wall along the crack to even make the repair stronger. The "V" doesn't have to be large, but just enough to expose some of the tank side area along the crack interior.

Larry

I have used Flex Seal to repair a TANK. not a gray, black or wash (THis was the Windshield Washer Tank on my car.

had to peal it off and re-do it with stuff that really sticks.. GOOP

How I'd repair

A small hole or seam split (NOTE Seam splits be very wary of) I would get a PLASTIC junction box cover. flat plastic with 4 screw holes.

I'd slather it with goop. likewise the repair area.. Then screw it down THROUGH the goop (Goop beyond patch) goop over screw heads and lay a bead along the edge.

NOTE: wait 10 mintues between slathering on GOOP and applying patch.

NOTE: How I installed the TORNADO the 2nd time.

opnspaces wrote:
I used plastimend on the rear wall of my black tank. So far it has held up and I don't see any reason that it would fail. They do provide a small piece of fiberglass window screen to use for reinforcement. I bought a bit more screen to make sure it was well supported.

This is probably nothing more than Acetone and ABS chips, but it worked for me so I'm happy.

Link

I use drywall mesh tape instead of screen, It has a larger opening and imbeds better. Probably more flexible too.

I used plastimend on the rear wall of my black tank. So far it has held up and I don't see any reason that it would fail. They do provide a small piece of fiberglass window screen to use for reinforcement. I bought a bit more screen to make sure it was well supported.

This is probably nothing more than Acetone and ABS chips, but it worked for me so I'm happy.

Link

I have used it on some repairs. I would use it on a temporary, internal repair, such as the shower. I would not use it on an external application, such as a cracked tank. Won't hold up under pressure for long. Temporary applications because while very sticky, it will work loose under many applications.

wanderingaimlessly wrote:
If the crack is in the bottom, in an area where the tank is going to flex a lot, and not well supported chances are slim an adhesive will last too long as the tank fills and sags.
You may want to look at adding a support under the tank to take some stress off of it.

It's on a side wall. Thank you.

RobWNY wrote:
Maybe the Flex Seal didn't work because you didn't apply it with a big smile while yelling out "It's like liquid rubber in a can!"

LOL

Sooner Schooner wrote:
Have any of you used a Flex Seal product to repair a crack in a holding tank?

It's garbage. Stay away from EVERYTHING Flex Seal!

Maybe the Flex Seal didn't work because you didn't apply it with a big smile while yelling out "It's like liquid rubber in a can!"