by Craig
(Westboro, Ma)
porosity in aluminum weld,
This is on a tube with flanges and is being tested for leaks with helium. No visible porosity on the surface of the weld, none seen in process, but keep finding it or chasing it after it's ground flush.
P.S
I too have been welding for 30+ yrs. Do certified welding for the DOD, also do welding of many different types of alloys for Oceanagraphic research Woods Hole.
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jody here from welding tips and tricks...
Craig, I have been having great success in eliminating porosity in aluminum welds by using a 80/20 helium/argon mix.
For some butt welds that were getting about a 50 percent reject rate in x ray...went down to about a 1 percent reject rate.
If you are using 5356 and have a choice to use 4043, the 4043 usually has less of a problem with porosity.
also, scotchbrite can cause a whole bunch of issues.
good luck bro,
Jody