Tig welding, type of metals and cleaning techniques

admin

HiI'm a newbie to tig welding and have a bunch of questions but I'll start with a few. Can you guys explain the difference between some of the basic metals like chromoly, mild steel, SS,.........? Pictures would be helpful. I know some basic charecteristics but may not know what is important about these metals or when to use one or the other for welding. Are there any metals that shouldn't be welded because they could cause health problems?What are some of the things you guys do to prep your material before you start welding? I've heard of people using wire wheels and acetone to prep their metals? Do you guys use acetone? If so what is it and where could this stuff be picked up?Thanks guys, I appreciate your help.
Reply:Welding almost all metals has some health risks. Galvanized steel is one of the big ones to avoid welding on or take extra precautions with due to zink poisoning. stay out of the smoke. Tig is a poor choice for galv anyways so it most likely wont matter.Chrom moly has a higher strength than mild steel and requires a bit more care when welding to prevent cracking and retain its strength. Its used in roll cages and so on for this reason vs mild steel. High strength and low weight, preheat/ post heat is often required.SS should be self explanatory as far as basics go. The 3 series SS are weldable like 304, 316 which is what you normally see welded. Not all SS are easily welded. High corrosion resistance is the big reason for this, and it looks good.Mild steel is most likely what you will build everything out of. Carts, structural work, you name it its most likely mild steel of some sort unless you are building to a design spec.AS far as cleaning I don't use a wire brush on steel. It generally doesn't remove the mill scale or rust , just polishes it. I grind or use a sanding pad to make the surface bright and shiny. This removes all the surface contaminants. Acetone is a great degreaser and if you have oils from cutting or machining it will quickly remove the oil and evaporate and leave no residue. You can get acetone for paint stores and Home depot / Lowes. It is very flammable and not the greatest stuff to get on your skin or inhale it, but a small bit won't hurt. I seldom wipe down most ground steel with acetone unless its got oil on it. I don't do critical welds so I am not worried about a tiny amount of contaminants because I didn't degrease everything. I just wipe off the dust with a clean rag.Hope this helps. Good luck.
Reply:Ditto, especially on the CM steels part. Many times the welding process neither starts nor ends with an arc. It may be a series of steps including a preheat, then welding, then a post heat treatment of some kind, as well as the cleaning steps involved.
Reply:Originally Posted by weldingguyHiI'm a newbie to tig welding and have a bunch of questions but I'll start with a few. Can you guys explain the difference between some of the basic metals like chromoly, mild steel, SS,.........? Pictures would be helpful. I know some basic charecteristics but may not know what is important about these metals or when to use one or the other for welding. Are there any metals that shouldn't be welded because they could cause health problems?What are some of the things you guys do to prep your material before you start welding? I've heard of people using wire wheels and acetone to prep their metals? Do you guys use acetone? If so what is it and where could this stuff be picked up?Thanks guys, I appreciate your help.
Reply:Wow DSW, makoman, and zodiac thank you so much for all the info guys. I love checking out this website cause I learn so much each time I come on here. Thank once again!