"Newshound" wrote in message
...

Mike" wrote in message
...
Use a self tapping screw and JB weld. Clean area real good .Rough the
surface.
Tap hole. Apply a generous load of JB and insert screw. Apply excess over
the top of everything to seal it up for good.

With a self tapper there is always the possibility of setting up a
galvanic cell inside, and speeding up the corrosion. I'd go for mesh and
epoxy outside (where the epoxy also keeps oxygenated water off the mesh,
so that even if there is a dissimilar metal pair connected, there's no
oxygen).

My experience from seeing the inside of a few dead aluminum hot water tanks
is that there is always corrosion in other areas, just waiting to be the
next leak. They are like looking at the surface of the moon, little patches
of flat craters, being dish shaped. To merely drill in the center and epoxy
WOULD solve the problem temporarily in that area, but putting a patch larger
than that outside makes the area you are building up a lot bigger, so that
it is over the "crater" on the inside. If it corrodes more in that thin
spot in the center of the crater, it will just come out where the epoxy is.
And if you are drilling into the thinnest part of the crater, you won't have
much "meat" to anchor to.

Now, I know this is not an aluminum hot water tank. I do not know what this
material is, and if, when it is dead, if you looked inside, exactly what the
post mortem examination would reveal. The best way to understand what
happened and what the best fix would be is to do a post mortem, but that is
what the OP is trying to avoid for as long as possible.

However, once the tank does give up the ghost, cut it up. Examine the
interior. See what's there, and what might be the best thing to do in the
NEXT case. Also, you can do some tear apart of the actual repairs and see
how they performed. There will be a lot of information and things to be
learned there, so don't just chuck it without examining. Maybe a sheet of
fiberglass with two element fiberglass dope would have worked better.

Anyway, that is what I would do. YMMV. I consider it a good day if I have
learned something new.

Steve