Flex Seal repair on grey tank.

[Sooner_Schooner]

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

[map40]

1 or 5 minutes epoxy with fiberglass polyester cloth. Epoxy layer, polyester layer, epoxy layer, polyester layer, epoxy layer. Loctite epoxy will remain semi-flexible. It will never come off

[Ralph_Cramden]

LarryJM wrote:

Ralph Cramden wrote:
Just because its colored black means nothing. Alpha Systems tanks are on many RVs. Theyre black and are not ABS, they're HDPE.


ALPHA SYSTEMS

It's really easy to determine ... just wet the tank with Acetone and if it becomes sticky its ABS unless some other material dissolves like ABS to Acetone.



Larry

Even easier is to look at the connection where the 3" abs pipe connect to the tank. If its glued its abs, if its mechanically connected with a clamp, its probably HDPE.

Or look at the flange on the top where the tank hangs on the spreaders. If its flat and around 1/4" thick its abs. If its about 1" thick and is blow molded into the tank its HDPE.

The fact is if its HDPE it probably never cracked to beging with so its a moot point. Its a better material for a tank than abs.

[LarryJM]

Ralph Cramden wrote:
Just because its colored black means nothing. Alpha Systems tanks are on many RVs. Theyre black and are not ABS, they're HDPE.


ALPHA SYSTEMS

It's really easy to determine ... just wet the tank with Acetone and if it becomes sticky its ABS unless some other material dissolves like ABS to Acetone.

Larry

[Ralph_Cramden]

Ralph Cramden wrote:

Ralph Cramden wrote:
Just because its colored black means nothing. Alpha Systems tanks are on many RVs. They're black and are not ABS, they're HDPE. You cna attempt to glue, flexseal, or essentially cobble together a repair, but if the tank is blow molded HDPE the only permanent solutions that can be counted on 100% are either new tank or plastic welding.


ALPHA SYSTEMS

And why in the hell doesn't this board have a delete function for when you try and edit and mistakingly hit the quote button. You would think based on the net worth and business dealings of Marcus Lemonis, the board associated with his company would not be running software developed in the days of the Packard Bell X86 pcs LOL.

[Ralph_Cramden]

Ralph Cramden wrote:
Just because its colored black means nothing. Alpha Systems tanks are on many RVs. They're black and are not ABS, they're HDPE. You cna attempt to glue, flexseal, or essentially cobble together a repair, but if the tank is blow molded HDPE the only permanent solutions that can be counted on 100% are either new tank or plastic welding.


ALPHA SYSTEMS

[Ralph_Cramden]

Just because its colored black means nothing. Alpha Systems tanks are on many RVs. Theyre black and are not ABS, they're HDPE.


ALPHA SYSTEMS

[LarryJM]

Drew A. wrote:

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

X2 on this stuff. It works great. Fixed my black tank at a crack where the outlet pipe is. It's now better than new. Not worth doctoring up your own concoction of ABS in my opinion.

Except for the fact that the Plastimend kit will run you 2 to 4 times as much as a qt of acetone and some ABS material. Also, you'll have a bunch of Acetone leftover for other uses.

Larry

[Drew_A_]

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

X2 on this stuff. It works great. Fixed my black tank at a crack where the outlet pipe is. It's now better than new. Not worth doctoring up your own concoction of ABS in my opinion.

[LarryJM]

mobeewan wrote:
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.

While some ABS glue has ABS Resin in it not all do and even the glue with the Resin in it isn't IIRC more than about 40% resin. It appears that both the clear and cream colored ABS glue doesn't have resin, but the black from Oatey does. For those reasons I did not include nor really recommend using ABS glue for a repair like this.

When making a paste just remember it takes some time for the Acetone to fully dissolve the ABS and you really want the paste to be smooth w/o any lumps. It took me a couple of days to make a shot glass sized amount of paste dissolve pieces of ABS about 1/8 the size of a pencil eraser.

Larry

[landyacht318]

Amazing goop has a Marine version too. I've not tried it. Says it is UV resistant, which the regular version most definitely is NOT. They actually have several different versions.

Sanding with 80 grit for mechanical tooth is wise, but also wise to wipe with a solvent before using fresh new sandpaper and scuffing in a cross hatch pattern. No point in pushing containants into the sanding grooves

I have saturated light weight fiberglass cloth with Amazing Goop. thicker cloth does not saturate completely but still aids repairs, especially on those repairs needing to remain flexible.

[mobeewan]

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.

[LarryJM]

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

[wa8yxm]

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.

[joshuajim]

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.