Does code, either D1.1, D1.7, D 1.6... have anything about a spool of wire and how long it can be exposed to the regular atmosphere?  I get told we have a source inspection coming up and to cover up any exposed wire.

Now I understand dust particles landing on the wire, and it possibly contaminating the wire, but on mig machines with exposed rolls is it really necessary when they are being used in constant production?  I think it looks worse to the people coming to see the shop when there are plastic bags over the spools. 

I have been in shops doing inspection where they built stainless on one side and steel on the other and ran into rusting issues from not seperating the work stations properly, steel dust fell onto some exposed open root weld grooves and no one thought to clean it or prep and the stainless welds ended up rusting through.

As long as you have a dust jacket on the wire line going into the feeder isnt that enough?

Some shop environments are better than others with regards with air quality and the need to protect bare electrode and filler metals. As a general principle I believe it is good practice to cover the filler metal regardless of the form.

It is not uncommon to watch welders grind welds or prepare grooves with their grinders while spewing grit all over their bench and filler metal and anything else that might get in the way. Never mind grinding, I was in one shop where the welder was doing some carbon arc gouging. The sparks and molten metal was landing directly on a freshly delivered pallet of flux cored electrode still nicely packaged not five feet away from where he was gouging.

Personal preference: I like to see all filler metals stored in a manner that will protect them right up to the time when it is actually consumed by the welding arc. In the case of GMAW and FCAW the cardboard shipping box  can be cut to fit over the electrode spool that is in place on the wire feeder. GTAW; the rod can be placed in a plastic or metal tubular holder with a cap.

It isn't just the debris from grinding and gouging that can be a problem, mists from machining operations can be a major source of contamination if machining and welding are both conducted in close proximity.

For the most part, it is a matter of training and reinforcing and rewarding good work habits. It doesn't take much effort on the welder's part to protect the integrity of the filler metals being used. The consequences of not protecting the filler metal can be very expensive when it adversely affects the quality of the welds.

Best regards -Al