dpb wrote:
On 10/13/2012 12:34 PM, Swingman wrote:
Been putting up with a slow leak in the air compressor and simply
haven't had time to address it. With the last project that is not in
planning stages out the door, this morning was a good time to stop
procrastinating:
...

Just tested my brazing job on the small airless tank I had posted
about a while back--still have a small spot or two...

For some reason I've been unable to figure out the brazing stuck very
nicely on one side of the patch (used a piece of 1/8" flat stock to
cover the stretch where the failure line was apparent) but can not
seem to get it to do so consistently on the other. I'm not an expert
but never had this kind of inconsistency on a single job so I'm at a
loss of what the issue is.

So... a couple of thoughts come to mind. One is cleanliness of the surface
to be brazed and the other is the actual integrity of the material. In
order to get a good braze joint, you have to be able to heat the metal to
red hot. If you're not doing that, then you're just flowing molten brazing
rod onto a surface that it won't adhere to. If the surfaces can't be heated
to red hot, perhaps because of corrosion, then same problem - no joint.
Brazing is a lot like soldering - you heat the surface and apply the rod to
achieve a melting together of the rod and the materials. You have to have
stable material and proper heat, and no buggers like dirt and rust.

--

-Mike-