Black Holding tank on 2009 Monaco HR Neptune leaking

[Waterboy]

Would a plastic welder with a nitrogen plastic welder fix this crack in my black Holding tank? Has anyone used Plasti-Mend to fix cracks in black tank.?

[desertdeals69]

A plastic welder will work.  If the crack is in a high stress area a extra piece welded over the crack will help.

[manholt]

What would be more cost effective?  IMHO, I would empty tank and replace with a new one!

[desertdeals69]

If it is accessible without removing we have welded it, usually takes an hour labor.  I don't have an RV tech at the present so will just repair boats.

[richard5933]

I've used a plastic welding gun (like a concentrated heat gun with special foot attachment) to repair a seam which opening on my fresh water tank. Will it work on your black tank? Depends on the material used to make your tank, how structural the area is that has a crack, and your ability to get the area thoroughly clean the crack.

If the crack is in an area you can easily get to and it's possible to thoroughly clean the edges, there would be no harm in giving it a try. Like mentioned earlier, you might do well to add some additional material over the crack once the crack itself has been welded together. Once it's repaired, fill it with water and see how it goes. You can always replace the tank afterwards if the repair doesn't hold or if you are suspicious of it.

[rayin]

One day I got ambitious and pressure-washed my black tank. That really cleaned it to the plastic, and revealed a crack in the bottom that had been plugged with TP. I had it plastic-welded at the local Camping World. That was 5 years ago, still  holding.