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kamaroman68
01-30-2006, 06:44 AM
I own a miller 251 w/meters mig welder. I have posted before about welding stainless to mild steel but I am unsure about the welder settings for this type of work. I will be trying to weld 1/8" s.s. to mild steel with a thickness of .045. I am using .035 309L stainless steel wire. According to the welder settings which I know are not set in stone says to set the voltage to 20 and the wire speed to 350. But these settings are for a tri-mix gas and 308 stainless wire. I will be using C25 as Matt had stated in a previous post. Regular 1/8" steel gets welded if I remember right at 18 volts and a wire speed of 240. Do you guys think I should just mess around with some scrap stuff or is there a better way of setting the starting settings? Thanks Chris

kamaroman68
01-30-2006, 06:45 AM
One other thing. 90 percent of the welding will be rosette or plug welds if that makes a difference. Thanks Chris

Matt@RFR
01-30-2006, 08:05 AM
Chris, yeah, ignore the tri-mix settings.

Basically you'll be treating these joints just like mild steel, with the possible exception of voltage. Use what is recommended for your thicker metal (1/8" = 240IPM w/ .035 wire). That gives you enough amperage to get fusion and penetration on the 1/8" member.

Then tune the voltage in to where you like it. Any stainless wire will want a different voltage than you use with mild steel wire.

And a note about rosette welds. Treat them exactly like any other lap or fillet weld and weld the joint, do not just start in the middle and fill the hole up. That won't get you anything except a bunch of heat.

kamaroman68
01-30-2006, 08:54 AM
Hey Matt thanks alot for the information. Are you getting annoyed with all of my questions yet? Now that you answered those questions here is another... OK Now on the top side of my custom rocker panel the 1/8" metal will sit on top of the .045 thick metal. I will drill 1/4" or 5/16"holes through the 1/8" to plug weld to the .045. So I definately don't want to hit the center of the hole with that power setting or I will blow through the smaller metal. Should I angle the gun so the stickout first contacts the 1/8" metal and kind of roll it into the center (.045) metal or push the puddle. The bottom is just the opposite I will make holes in the thinner metal and hit towards the center of the 1/8" and push the puddle to the outside again to avoid burn through. I have never tried this but is it also possible to weld laying on your back and weld overhead? If it is possible how do you see the puddle without having a shower of sparks landing all over you? Thanks Chris