Not much here either, but the difference between welding galvanized steel and welding uncoated steel comes down to the low vaporization temperature of the zinc coating. Zinc melts at about 900 degrees F and vaporizes at about 1650 degrees F. Since steel melts at approximately 2,750 degrees F and the welding arc temperature is 15,000 to 20,000 degrees F, the zinc that's near the weld is vaporized.  So, by the time the weld pool freezes, the zinc is gone.  If galvanized steel is going to be welded without removing the coating, it's important to point out that the welding electrode composition should be checked to assure that the silicon content is very low because a high silicon content can cause zinc to penetrate the weld metal, leading to cracking.  I think that the actual recommended level is a subject of debate.  All this being said, I believe that not removing the coating prior to welding would simply be too risky.  In our shop, we remove it.