On 9/26/2015 8:05 AM, Bob F wrote:
Don Y wrote:
On 9/25/2015 10:25 PM, Bob F wrote:
I bought some Locktite Vinyl glue recently that might work to glue
the leak. I'd try to find the leak, then spread it a bit and squeeze
the glue in, then maybe apply a fillet of glue on the outside and
let it dry overnight.

I suspect this is a hairline crack. It takes *hours* for the barrel
to empty. And, as the water level falls, the rate of draining seems
to be reduced (hydrostatic pressure).

I suspect I will have to scrub the inside and outside (sediment that
accumulates in the barrel) and then watch, carefully, for any water
leaving the bottom surface.

First thing is to just look for the crack. It may be completely obvious to to
water stains or moss/algae growth.

Already tried that. No sign of anything on the outer surfaces (sides);
no moisture, etc.

Underside of bottom, of course, is completely wet (that's where the water
would accumulate regardless of the location of the crack). No signs
of a crack (like you would expect to see if you'd struck it in an
arbitrary spot with a HAMMER).

Barrel appears to be two "half barrels" (left/right) fused together.
Seem is not visible along sides but is so along the bottom. This
is where I am guessing the leak must be -- some portion of that
seem having failed over time.

But, the only way to locate it would be to dry it, clean it, refill
it (partially) and watch (carefully) for signs of water seepage around
that seam.

Barrels are white HDPE so "wetness" isn't really very easy to spot.
I figure putting a fair bit of Miracle Grow in the small amount of
water would give it enough color to be more noticeable -- without
having to later worry about getting vestiges of the MG out of the
barrel (who cares if a plant gets a tad more fertilizer from this
rainwater!)

I could add, I had some luck at one time repairing a plastic kayak hole with a
hot glue gun, by first heating up the plastic with a heat gun, then applying the
glue. It bonded much better to the heated plastic.

Since you say you can reach inside, you could use the vinyl cement with a patch
of heavy rubber or vinyl coated fabric.

I would certainly use care when moving it after repairing, as no repair will be
a strong as new.

That's a concern. The barrels aren't stationary --- we move them to drain them
(can never get the last few inches of water out of them without tipping them
over -- not keen on being a mosquito birthing center!). And, before/after
Monsoon, they are stored elsewhere on the property (eyesore).

I.e., if they are going to be failing, over time, better to just plan on
replacing them instead of trying to fix them (we've been looking into
a 2000G cistern... something that wouldn't need to be moved, emptied, etc.)