Black Water Tank Leak

Bayley wrote:
I'm a little confused on the type of plastic the tank is made of.
I contacted the manufacturer of my trailer and they said it was LLDPE. In my research it says LLDPE is white or yellowish in color. My tank is black in color. My guess is it is ABS....does that sound correct?

Yes confusing, need to be careful. Elkhart plastics Inc is a large manufacturer of RV holding tanks and their black tanks are black but made from polyethylene. Could only guess they add the color as they are not using virgin material??

https://www.recpro.com/8-gallon-rv-holding-tank/

"polyethylene resin
These blackwater tanks are made from rotationally-molded polyethylene resin that provides strength, long service life, and great protection against cracks, rust, and corrosion. Blackwater holding tanks are manufactured by Dura-Cast and Ronco. RV septic tanks can be used for most recreational vehicles makes and models."

ABS tanks have kind of gone away years ago. Most tanks are this material above and COLOR has no bearing on what material they are made of. A good tell if you suspect ABS is to look at the 3 inch exit fitting of the tank. ABS tanks will show/have ABS cement where the pipe goes in. IF you have a Hose Clamp, it is not ABS. Doug

I'm a little confused on the type of plastic the tank is made of.
I contacted the manufacturer of my trailer and they said it was LLDPE. In my research it says LLDPE is white or yellowish in color. My tank is black in color. My guess is it is ABS....does that sound correct?

If the crack is on a bottom corner, odds are any type repair will be futile, due to the tank flexing when full and empty. But, it does not hurt to try. Make sure the area is CLEAN and DRY. Use sandpaper to rough up the ABS. Then apply the plastic glue material WITH a small piece of standard fiberglass screen material to strengthen the repair and prevent the tank from flexing. Is this a CRACK? If so, you will want to drill a small hole at the end of each end of the crack to prevent the crack from continuing. Doug

Moved to Tech Issues forum from DIY.

rhagfo wrote:

12thgenusa wrote:
ABS tanks can be easily, successfully, HF plastic wielder and inexpensively plastic welded. I've had several repaired by a professional. I see Harbor Freight offers a plastic welder, but I don't know if it is a worthwhile tool or how much skill is involved.

I used the HF plastic wielder with good success. I first melted the wire screening over the cleaned area to be repaired, then added repair plastic over it.

I used one of these to repair an old lawnmower fuel tank a few years ago. It's still holding up.

12thgenusa wrote:
ABS tanks can be easily, successfully, HF plastic wielder and inexpensively plastic welded. I've had several repaired by a professional. I see Harbor Freight offers a plastic welder, but I don't know if it is a worthwhile tool or how much skill is involved.

I used the HF plastic wielder with good success. I first melted the wire screening over the cleaned area to be repaired, then added repair plastic over it.

Plasti-Mend is also my choice.

do what time2roll says.

Black ABS can be repaired with a product called Plasti-Mend. If the damage is due to stress flexing on a corner consider adding some sheet ABS to stiffen the repair.