Comments on forge welding and welding fluxes from the alt.crafts.blacksmithing newsgroup: ===== recommended flux for mild steel is clean sand and borax. mixed 4 parts sand and 1 part borax.. Ordinary borax contains water, when this is heated, bubbles and is cooled it becomes borax glass. Pulverize this and mix 4 parts of this to 1 part sal ammoniac (ammonium chloride). This mix is good for carbon steels.. High carbon steel flux is 50% anhydrous borax, 25% boric acid and 25%silica sand. Where would I get these?? Let your fingers walk.. Call chemical supply houses.. NEXT... Pickling solutions... 50% hydrochloric acid and 50% water (MIX CAREFULLY!!) choose one of the following 1/2 pint Sulfuric acid to 1 gal water 6 oz sulfuric acid, 5 oz anhydrous ferric sulfate, to 1 gal water 1/2 to 1 pint phosphoric acid to 1 gal water 8 oz sulfuric acid, 10 oz hydrochloric acid, to 1 gal water The phosphoric acid solution is available at a auto supply store. Ask for something the car painters use called metal prep. cleans rust off car parts before priming. ALSO DOES NOT leave a chemical residue like the others, it IS paintable.. My book here talked about Blueing and other such finishes and mentioned Metal Finishing Guidebook Directory, and another is Black Oxide Coating of Ferrous Metals- both of these put out by the Department of Defense (both probably older books, too) Blueing solutions are:::also TALK TO A GUNSMITH!!! Blueing is a controlled VERY FAST rusting.. there IS a BROWNING technique, too, but couldn't find info in the books I have.. #1. Sodium Thiosulfate-3 oz Lead Acetate-2 0z, 1 gal water. #2. 2 oz Ferric chloride 2 oz Mercuric nitrate (wonder if this is even available any more???) 2 oz Hydrochloric acid 8 oz alcohol 8 oz water use at room temp. clean the piece soak it for 20 minutes, and let stand over night, soak again for 20 minutes. Boil it in clean water for an hour. Dry. rub with oil. #3. To 1 gal of water add 4 oz phosphoric acid and 1 1/4 oz soft iron filings. Boil the piece for 1/2 hour and dry and oil or wax it. Have fun.. ==== > > I went to the store the other day to buy some borax...If I recall, the > old 20 mule team borax was just called that, and in a black and white > box. (probably with Ronald Regan's face still on it). All the store had > was 20 mule team borax laundry conditioner in a green box. Does anyone > know if this is still the same stuff, just marketed different. ...snip... I understand that it is the same thing, but be sure not to get the scented type -- it allegedly can make you quite sick. ===== Read the contents label. If it says pure borax your home free. My borax box is green, with a white background on the front and a picture of a little boy in western outfit holding a whip and the mule team behind him on the desert. It says its "Deodorizer, Detergent Booster, Water Conditioner, and Stain Remover" but doesn't say "welding flux" any place on the box....grin. It is the pure stuff and works very well for me. ====== I've used the standard laundry borax you refer to. The only problem with this material is that it has a fairly high water content...this diminishes its effectiveness as a flux (because of the steam). If you can find anhydrous borax, this is better. Or you can bake some of the laundry borax in a tin can in the oven and make your own. I also like to put some iron filings (from my grinder bench) in the flux...seems to give me a better weld. If you start researching recipes for welding fluxes, you're in for a lifetime of study! Good luck with your welds! ===== I don't really think that anything more than pure borax is of any advantage if your forge environment is a good one and you scarf your joints properly. Preparation is everything in forge welding. If you do that it will only require a couple of light taps to do the weld and a few more to shape it up. I don't think you gain anything with iron filings except a mess on your work. Borax cleans off easily too leaving a clean weld.