I recently learned that using 95% Ar / 5% CO2 (AC-5) sheilding gas reduces fume levels and that Hobart Brothers has been working on low fume generating wires for a while now which accentuate the AC-5 use. When I asked about their products, Hobart responded with the following:
"I have a link for our flux cored wire for AC-5. TM-910 is a good
product for use with AC-5 (95% Ar / 5% CO2) shielding gas. The fact that AC-5
shielding gas may be used will result in much lower smoke levels. We see similar
amounts of Mn in the fume as our other E71T-1 products but the substantial
reduction of overall fume reduces the amount of Mn. A 40% reduction from even AC-25
may be realized. Compared to CO2, the reduction can be much higher than
40%."
http://www.hobartbrothers.com/product_details.asp?prodID=144"We have a carbon steel metal cored wire that also can be used on AC-5
shielding gas (and most of them can be). We do have a specific one that
is designed for lower fume generation rates however. That product is
Tri-Mark brand Metalloy 70X. See the link below."
http://www.hobartbrothers.com/product_details.asp?prodID=98I asked my welding consumables supplier for a quote on the Metalloy 70X and found it to be 120% more expensive that the Lincoln MC-6 I'm currently using.
I've requested further info from Hobart to define the exact fume levels that may be expected from their product so that I can compare it with other wires and see for myself which is better.
My goal is to be prepared when OSHA pushes through the new, greatly reduced, welding fume PEL's (Permissable Exposure Limits) they've been promising.
Tim