Silicon Bronze and Galvanized steel

By TimGary (****)

Date 02-01-2008 19:18

We're seal welding shear cut corners on 16 gage galvanized sheet.
One of the old hands in my shop suggested using Silicon Bronze GMAW wire as he remebers using it before to great effect, as he didn't have to remove the zinc and the wire flowed like butter.
I can see that it is good for this application, without removing the zinc, but something isn't quite right. Too much spatter and not as smooth as the old hand remebers.
This is not code work so please don't fuss at me about removing the zinc.
I'm wondering if the 92% Argon - 8% CO2 sheilding gas we're using could be the problem.
Does anyone have expierience with this?

Tim

By Superflux (****)

Date 02-01-2008 20:38

I've used .035 GMAW with 100% Argon and seemed to give good clean beads except for where there were "drips" or excess blobs of zinc from the hot dip. As long as you can keep heat from building up (ie. haul "A") it won't even make the little white "spider webs". Used the Silicon Bronze on all sorts of plated metals with xlnt results in my own FC2002 Code Shop. It also GTAWs well with 100% ARGON on ferrous. I wouldn't GTAW on the galvinized...the zinc cruds up the tungsten too much.

By swsweld (****)

Date 02-01-2008 23:49

Hey Tim, I have welded sheet metal with silicon bronze using carbon air arc gouging rods instead of tig welding it. It works great. Just insert the gouging rod in the stinger. Can't remember if it worked w/-or+ polarity. Try it if it doesn't seem right switch polarity and give it another shot. Tacks need to be close but that is always the case w/ sheetmetal. Cheaper than argon and tungsten. I hate welding sheetmetal.

By TimGary (****)

Date 02-03-2008 14:51 Edited 02-03-2008 14:55

Wait a minute...
I'm not sure I'm following you...
Do you mean that you put a gouging rod in a stinger, set the power source at low enough amperage to carry an arc but not blow through the sheet metal, and then feed in silicon bronze filler like you were tig welding, with no sheilding gas?
That sounds crazy!
Maybe I misunderstood..
But then again, I know I have not seen it all...

Please clarify
Tim

PS
For those of you who may be interested...
Switching to Pure Argon and fine tuning the parameters was the trick.
This process works exceptionally well for galvanized sheet metal.
I especially like the fact that almost no hazardous fume is generated.
Tim

By swsweld (****)

Date 02-04-2008 01:40

You described it perfectly. Use 1/4" rods, straight polarity, low amps and use gouging rods instead of tungsten and argon. I used 100% argon and tung. before I learned about this. I had welded pipe and steel for more than 20 years when I tried this and i was very sceptical. It does sound crazy but it works great. Out of curiosity give it a try.

This process is called Carbon arc Welding CAW basically an obsolete process. You stated this was for non code work. The worst thing you may encounter is some carbon contamination.

Today I saw on MythBusters that you can teach an old dog new tricks. Not that you are an old dog, was refering to me :)

By Superflux (****)

Date 02-04-2008 10:38

Try it on nickel and chrome plated... it's even more phenomenal.....So Clean............ BUT !!!!!!! I can't wait to try the CAW thing... I'm truly a fanatic for "Old School" ..... Sometimes, there is no substitute for tried and true PROVEN TECHNOLOGY! There's a reason why these so called archaic (OAW etc..) processes are still around

By TimGary (****)

Date 02-04-2008 13:28

Amazing...
Thanks for the info!
I love learning new tricks!
I've not tried it yet, but I will.

Tim (old dog)