Robert or Karen Swarts wrote:
I have "welded" many polyethylene parts using a common electric soldering
pencil, anywhere from 25 to 125 Watts, and scrap polyethylene from any
source. With a little practice, you could do it yourself.

Welding parts together is one thing...but mending a crack in a tank adds
another dimension, because you have the weight of the contents--8.333
lb/gal for water and waste, which would be 227 lbs in a 27 gal tank)
pushing against the walls of the tank trying to pull the crack apart
again...if the contents are shifting while the boat is underway, they're
pushing even harder. Then there's quality of the original tank material
itself to consider...why it split in the first place. Even if the weld
holds, will the same forces that created the first crack cause a split
somewhere else?

So, as I said earlier, if it were a water tank he'd have little to lose
by trying to mend it. But when it comes to waste tanks, the wisest
course is replacement.


--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1