We do about the same things as Chet and John. In the shop, we weld with FCAW for structural and GMAW for stairs, handrails, ladders, etc., and our field erection crew uses SMAW. We use nozzle dip throughout the shop. In the structural department, we use spatter spray when we weld in tight areas, and on all AESS areas. In the misc. department we use spatter spray on most everything because of the exposure of the finished product. Some misc. shops use the 75/25 gas with .035 diameter wire. It essentially leaves no spatter, but the lack of penetration worries me, so we use 98/2. It doesn't leave much spatter, but we spray everything to make the cleaning easier. Years ago I was taught that materials are cheaper than labor, so if I can spend a few bucks on anti-spatter and it speeds up cleaning the welds and adjacent areas, and eventually pays for itself, go for it. As Chet stated, be careful not to saturate the joint with it, because it can cause porosity, and you also end up wasting it. Personally, I don't like to see weld spatter on a finished product, whether it is exposed or not. I know that D1.1 allows tightly adhering spatter to remain on the steel unless it needs to be removed for testing purposes, but I just think it looks so unprofessional. I've seen work of some other fabricators, and there's spatter all over the place. On some of this stuff, it looks like the only thing the welder did is to clean the slag, and in some cases, didn't do a very good job of that. When AESS is not a requirement, we don't try to get every speck of spatter off, but I'd say that we remove at least ninety something percent of it. In addition to slag removal, spatter removal is part of the welders responsibility. It doesn't really take a lot of time without the spray, unless it is in a tight area, so we're not really running up the man hours by trying to get most or all of it off, because as Chet stated, it scrapes off easily with a brick chisel. One last thing. I'm wondering how this in line spatter shield that Mudbone is using has an effect on the essential variables in Table 4.5 of D1.1 regarding shielding gas.

We are welding 10-18 steel with Er70S-6
24 volts.
180-200 amps
85/15 Argon/CO2 @ 35cfh.
We have an In-House lab, so I am able to monitor effects of process changes. I started using this product in Nov 2003. to date there has been no effect on the weld as far as appearence, fused legs, throat or depth of penetration. The advantage I've found to using the in-line system is cleaning the equipment. With the dip gel, the fixtures and surrounding surfaces were coated with a sticky film to which all of the welding residue would stick. this would have to be cleaned by scraping and scrubbing with solvents. With the Spatter Shield, clean-up is just a mater of brushing or blowing. The only problem I've encountered is getting through to the weld operators that it's impossible to eliminate the spatter altogether. Our weld cycles are short (7-10 second) and a ring of spatter builds up around the outside rim of the nozzle. With no anti spatter, this must be cleaned every 5-10 cycles, the dip gel extended this to about 20 cycles. The spatter shield extends this furthur to 40-50 cycles.