TWIMC;
	I used J B Weld as a temporary fix when my coolant level warning
switch (located on the coolant expansion tank i.e. immersed in coolant)
sheared in half in the middle of B.F.Egypt on a sunday. The repair held
for the entire 400mile trip BUT shortly there after gave out. The once
rock hard substance absorbed fluid and became  spongy! I personally
would not use it to repair aluminum heads in contact with anti-freeze
because of this. To be clear I am talking about the epoxy-like substance
that comes in two tubes and must be mixed.
	I regret that I did not make this connection earlier.

ken lewis
kernersvilleNC