how do I stop this from happening?

[gree box]

When I weld metals I get craters. Everything goes well when I start be then the craters. Little sparks fly out to. It's like there is oil or something in there. Tried it on different types of metal. Using 250ex with er70s-6 rod. Is this the right rod for general metals?

[Rambozo]

When I weld metals I get craters. Everything goes well when I start be then the craters. Little sparks fly out to. It's like there is oil or something in there. Tried it on different types of metal. Using 250ex with er70s-6 rod. Is this the right rod for general metals?

I prefer ER70S2, but S6 will work fine as well. Number one, is there any oil or contamination? TIG needs to be super clean. For used fluid fittings there can bee junk in the pores, so you might have to clean, heat the parts, then clean again to get all the gunk out. Or use try newfittings. Two, keep a very short arc and don't go too slow. You don't want to over-cook the steel. Three, make sure you have enough gas flow and the argon is clean and dry. Round parts like that do not trap much argon, so you will need more flow than flat plate or an inside corner. For a #6 cup I would say about 10-15 CFH. Finally, depending an material there may be issues with some alloys. Leaded free machining steels do not weld as nice, because the lead vaporizes and can make little bubbles like that. Keeping the heat down to a minimum can help.

[gree box]

I clean my aluminum parts very good before welding. I did not think metals needed to be as clean. That's likely to be one of my problems. Now that you brought up heat, I'll try less heat. I'm always using alot of heat. I like the idea of heating and recleaning. I do have er70s2 I' ll try that. Thanks.

[performance]

Any form of contamination on any metal causes porosity on any metal. You also likely have a coating on the fittings too which will be hard to remove.

[Kempy]

If those parts are machined from hex stock, they most likely are, then they have a lot of lead in them it is very hard to weld that type of fitting with ER70S-2 or S-6 they call it (Ledloy, a carbon steel with lead added to make the material machine better) when I weld it I use Stainless steel rod (ER316/316L) it seem to work the best.