Hmmm, so after doing some research it seems the silky stuff is because the metal was galvanized ... I had no idea anything on these cars was actually galvanized from the factory. Good thing I always wear a respirator when welding and decided to quit for the night after tack welding rather than welding up the rails. I guess I'll have to cut the tacks and go back and grind as much of the zinc coating of as possible ... tough to do, at least on the backside on the welds (inside the frame rails). 

I've read that welding galvanized steel results in brittle welds, 6sal6, as a former welder any input on this? Any idea how I should proceed? 

MustangSteve wrote:

Yes, the galvanized metal is the issue.  It also is emitting phosgene gas as you are welding it.  Hope you had good ventilation.  It can give you one heck of a very sore throat!.

 
Umm, welding on galvanized does not generate phosgene. Electric arc on galvanized vaporizes zinc which is the respiratory irritant. You can make phosgene when welding by combining chlorinated solvent (like original Brakleen) with electric arc and argon shielding gas. Phosgene does not make you sick, it causes permanent neurological damage and kills you, very painfully. DO NOT PRECLEAN YOUR WELDS WITH A CHLORINATED SOLVENT! Use acetone or a water based degreaser.

Fun fact: if you ingest enough zinc, it permanently kills your sense of smell.

Last edited by Hornman (7/27/2014 2:34 PM)

Good on 'ya!
Just grind what you can and go for it!
Galvanize is bad stuff if you breathe a bunch of it. Gives you chills and fever like the flu.Ache all over. Don't axe me how I know!!
If you got most of it off it won't weaken the weld. (Not the kind you are doing.....Not X-ray quality)
6sal6
Those little threads are kinda cute the way they float off,huh?!