Mike Marlow wrote:
dpb wrote:
On 10/13/2012 5:50 PM, Mike Marlow wrote:
dpb wrote:


Ground to shiny surfaces on all faces before starting...heat
shouldn't be problem; rod flows but then on cooling is occasional
minute fracture line along one surface edge. Meanwhile, same
technique to best as can replicate worked perfectly on other edge.

Almost sounds like contamination - wouldn't you agree? I know you
ground it down but, if the metal is sound where you are brazing, I'm
not thinking of anything else that could booger you up like this.

Me neither, but don't know where it could have come from...if were
disparate pieces that acted differently I'd see it at lot more
readily...

The reason I asked the previous question (about being on solid metal
and not filling a hole), is I'm wondering if capilary action may be
drawing moisture from inside the tank to that area of your work when
you apply the heat.

So... how is your rod melting in when you're on it? Look like a good flow
and all that? Try taking a wire coat hanger and wire weld it and see if
that behaves any differently. You've really got my curiosity up on this
one. I've been stymied like this before myself (just ask me about the
Toyota Corolla from hell...), and I understand the frustrations of doing
everything right and having unexplained problems.

--

-Mike-