[gerald]

Some folks use FLINT SILICA which can be bought "dirt cheap" at pottery supply places. I'm not sure whether this could be called "sand" from a technical standpoint. If you try it, be sure to buy the coarsest grit you can find as the finer grits can become airborne and inhaled. The last I bought was 200 screen. I haven't been able to make it work as well as plain old Borax, though. The feller who turned me on to it, Bob Patrick, says to sling it into the fire as opposed to putting it on the weld area as you do with Borax.