On Sat, 18 Feb 2006 21:14:24 -0800, Grant Erwin
wrote:

Lots of great advice. This problem is greatly compounded by the fact that the
shutoff valve which feeds cold potable water to this tank is malfunctioning and
will *not* shut off. It's a gate valve and it's just plain stuck.

Can you shut off the entire water supply, cut the supply line to the
tand and insert another valve?

Anyway, I tried high temperature RTV in conjunction with a sheet metal screw,
let it set up for a couple of hours, no way at all did it hold. Next I cut out a
patch of copper sheet about the size of a 50 cent piece and had a go at sweating
it on using plumber's solder. That's where I am now. Next step is to go cut the
water back on and see if it leaks through my patch. If so, off comes the patch
and I'll try directly brazing up the hole using bronze brazing rod and blue flux.

I know this patch won't hold for long, I'm just trying to get through the
holiday weekend with 4 teenagers here without having no hot water.

How about covering that patch with some more of the RTV and putting a
strap all the way around the tank (like a bandage) to minimize the
possible leakage?

Maybe you could hang some plastic dropsheets around the tank, now that
you have the floor drain working, and in case it springs another leak.