Contaminated braze job on cast iron

Tom Gardner wrote: (clip) I am concerned that even a small qty. of AL might weaken the joint (clip) ^^^^^^^^^^^ I suggest you do a test by brazing a piece of steel to the questionable area, and then test it for strength (short of breaking the cast iron.) If it seems to be holding, then melt the test joint, and proceed. If it comes out weak, there is a possibility that you can grind away the bad Al-brass alloy. Then test again.

Possibly by applying and brushing away braze a few times, you can "rinse" away the contamination.

Best of luck, and keep us posted.

Another thing to try might be to soak wire wool in flux, hold it in tongs, blast it up to heat, and use it to try to suck up the contaminated alloy. Something similar is used in electronics (on a smaller scale) for clearing up bad solder joints, occasionally...

You can build a big fire and get the whole part 10% above the melting temp of the polluted alloy. Then, the wool and flux will contact heat and suck nicely without cooling things down too badly. That's T melting plus 10%, in kelvins or degrees Rankine, not F or C. And at the same time you can preheat a pot of flux with wool in it, and pull it out ready to go (already phase changed) with tongs.

Yours,

Doug Goncz Replikon Research (via aol.com)

Nuclear weapons are just Pu's way of ensuring that plenty of Pu will be available for The Next Big Experiment, outlined in a post to sci.physics.research at Google Groups under "supercritical"