bushman wrote:
My holding tank has a small split 1/2" in the top, it is white plastic
(polyethylene?) 27 gallon seems fairly heavy. What is the best way to repair
this?

It's almost impossible to repair a PE tank, 'cuz nothing bonds
permanently to it. The only thing that does work is heat welding, which
requires melting both enough new poly and enough of the edges of the
crack to allow it all to run together to become a single mass again.
That takes a bit skill, to melt just enough of the tank without melting
enough of it weaken it. Just melting some P-Tex into the crack won't
work...'cuz unless the tank wall is blended with it, the same stress
that caused the tank to crack in the first place will cause the P-tex to
let go.

If was a water tank, I'd say give heat welding a try...or even just
drill small holes at each end of the crack to keep it from spreading any
further. If it doesn't work, it's just water. But a waste tank...if it
were mine, I'd bite the bullet and replace it.

--
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