Hi fellas,
Got a bit of an issue here.
I've just finished welding bends, etc into my pipe run for a 16kwr ducted mhi unit.
The copper is 1/2 and 7/8.
I religiously purge with dry nitrogen when I weld anything, but noticed this time round there was a whole heap of flaky black sooty **** blow out of the 7/8 when I cranked up the nitro.
Looks as though no nitro was used almost.

What's gone wrong? I'll try and post up some pics of the welds I cut out.

I'm very Hesitant to fire the machine up as is. I think at least I'll add a suction drier and hopefully that'll save my rmd from being clogged up with rubbish inside a month.


Thanks in advance guys