zord Posted March 30, 2012 Share Posted March 30, 2012 Hi as a new blacksmith I'm a little confused about the flux used for welding. Since I speak Hebrew I don’t know the meaning of the word flux. My question is what is flux? And are there types of it for different uses? Zord Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 30, 2012 Share Posted March 30, 2012 Fluxes serve a number of purposes in Forge Welding: example they help clean oxides from the surfaces, they help liquidfy scale, they help keep new oxides from forming some contain finely divided steel to make it easier for a weld to stick. There are types of fluxes that specialize in just part of these duties and other mixed fluxes. Typical of old style fluxes used for real wrought iron---the material---were things like clean quartz sand as real wrought iron is pretty self fluxing a simple barrier flux that works at very high temperatures was fine, (ground glass was another as was wood or rice straw ashes or even clay---the nests of a wasp called a dirt dauber in the USA used to be used!) As wrought iron is welded above the liquidification point of scale it didn't need much help. Higher carbon steels and modern steels need to be welded at lower temperatures and so different fluxes have been devised for them. Often based on borax with additives to help out---or just plain. Here in the USA there is a washing machine additive "20 Mule Team Borax" that is straight borax and used a lot. If you can't find borax like that "Anhydrous Borax" borax missing some of the ten or more water molecules attached to it is very popular---found at pottery glaze suppliers or through chemical dealers. Some people like it more than plain borax which tends to foam up like popcorn as the water is driven off. Anhydrous Borax doesn't do this. With higher alloy steels there is a greater problem with oxides of things like chromium and so more aggressive mixes are used to deal with them. The next step is probably just adding boric acid to your borax 1 to 4 up to 1 to 1. Here in the USA you can buy almost pure boric acid sold as a cockroach killer and preventer, Roach-Pruf, very cheaply compared to buying it medical grade at a pharmacy! With even higher chromium levels---like stainless steels some people go to much more reactive fluxes that are also MUCH MORE TOXIC---DO NO BREATHE FUMES! That are made by adding fluorspar, calcium fluoride, to the flux mix. If fluorine doesn't scare you *please* take up knitting instead of smithing! Perhaps a better way to go is to weld such alloys in a "box" a piece of square tubing with one end welded shut and the ground clean pieces stacked tightly in it, then a dollop of oil is added to it to scavenge any oxygen in it and the other end is welded *almost* air tight---a weep hole is left to allow for the atmosphere to escape as it's heated up. You then bring this to welding temperature and weld it as usual. You generally have to grind off the case afterwards but you can get very good billets indeed this way! Quote Link to comment Share on other sites More sharing options...
brianbrazealblacksmith Posted March 30, 2012 Share Posted March 30, 2012 Very good post, Mr. Powers! Quote Link to comment Share on other sites More sharing options...
eric sprado Posted March 30, 2012 Share Posted March 30, 2012 Zord: If you log on to Metal Artist Forum ,http://www.metalartistforum.com/maf/index.php, there is a man on there Avishai Wasserman who speaks Hebrew and is VERY knowledgeable about black smithing. He also has his own website. He recently did prayers in repousee that are a sight to see. Shabot Shalom, Eric Sprado Quote Link to comment Share on other sites More sharing options...
Thomas Dean Posted March 31, 2012 Share Posted March 31, 2012 Tsur Sada is from Israel, I don't remember exactly but I do know that it is in the southern part of the country. A fantastic smith and a great person. I'm not sure just how you can contact him but he would be a great person to learn from. I took a class from him several yrs back and have visited thru emails in the past. I'm not sure if he teaches any classes but if so you would do good by him. Quote Link to comment Share on other sites More sharing options...
Ted T Posted March 31, 2012 Share Posted March 31, 2012 Thomas, I agree with Brian about your excellent post about Flux Types. I also thought your post that was contained with-in the thread called “Introduction and Question” was expressed in a simple, direct and useful manner for the benefit of new or old hands to read and refresh themselves with some basics of acquiring steel that was safe to use. The other posts had very suitably covered the aspect of “What steel not to buy or use”, and then you brought the topic over the finish line of “What steel to Buy or Use.” I am truly grateful for you and several other knowledgeable people who continue to give freely, and share their hard earned knowledge and skills.Thank YouTed Throckmorton Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 2, 2012 Share Posted April 2, 2012 Thank you very much. I started smithing 31 years ago with only 1 book to go by and suffered a long and painful learning curve. I want to shorten it for others so we all can move on to new and unusual error modes! (Done a lot of weird stuff too checking out hypotheses in historical smithing...forge welding of layers of cast iron and mild steel is "interesting" in a quick get the fire extinguisher sort of way as the cast iron splashes at welding temps!) Quote Link to comment Share on other sites More sharing options...
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