One thing to consider: 4" bulkhead fittings are pretty large, and may
not conform well with any curves built into the stock tanks---a "flat"
rubber seal will not take to a curved surface, no matter how correctly
they are installed. Silicone may help, but usually wears out after a
time when exposed to the elements. I suggest you rethink the bulkhead
fitting size, unless you have a flat surface available on the tank in
excess of the seal diameter.


"Ted" wrote:

I used them on my preformed pond and they did not leak at all.
If they are installed correctly you should not have to use silicone, in fact
that could make them leak. The fitting should have a rubber gasket on one
side and then another rubber gasket and a "washer" on the other. The rubber
gaskets both need to go against the tank surface. The "washer" needs to be
on the nut side between the nut and the gasket. This keeps the rubber gasket
from bunching and twisting when you tighten the nut.


"Oingofan" wrote in message
.. .
I'm putting in 4" bulkheads into my 150 gallon rubbermaid stock tanks
and was wondering if anyone uses silicon to seal the bulkheads or to
just leave them as is (plain rubber). Once I put these tanks in
place, it would be a real pain to fix a leak, so I want to check what
everyone else has done. Has anyone put in bulkheads into a rubbermaid
stock tank? If so, what have you done and did they ever leak? Thx!!!
Oingofan