Welding question

[m3a1]

Here's a welding question directed at Rick and anyone else who cares to jump in.

Soon, I am going to be working on sorting out a transmission tunnel. I purchased some small squares of 16 gauge mild steel at Home Depot which is a tiny bit heavier than the panel I'm repairing. Appears they are going to be just the thing for this small project. Once they are formed, I will be butt-welding my new steel to the original stuff. I've obtained some .025 wire for my Millermatic 200 and I will be doing some experimentation prior to getting into the real thing because, to date, I've always used .035 wire...but I need a good starting point before I begin dialing everything in.

I think I already know the answer but here goes.... What is the general balance between power and feed rate? Am I looking for a high power setting/slow wire-feed speed for best penetration? I'll be welding from the back side to minimize the necessity for a lot of clean-up.

Cheers,
TJ

[rickf]

I don't know about the Millers settings but you will be looking for power on the lower end of the scale and wire feed to match. Usually there is a chart on most welders that gives a decent starting point and then you dial it in from there. On a 200 amp welder I am thinking you will be probably at about the lowest setting on the power or real close to it. The wire speed if I don't have a chart I start slow and then with one hand on the speed control and the other on the gun I start welding and bring up the speed until I hit that sweet spot of frying bacon. Are you using 75/25 gas or straight Co2? Co2 is going o be tough on sheet metal due to high penetration.

[m3a1]

Ok, so low and slow. 75/25 is what I'm running now.

[Hambone]

As you go up and down on your wire speed, so goes your amperage up and down, get it close with amperage selector and fine tune with wire speed. Always use spot welds and stitch welds with light sheet metal, it loves to distort with heat.

[m3a1]

Excellent. I never thought of wire speed affecting amperage but I can get my head wrapped around that. I'm concerned about the gauge of my new metal. What is most readily available to me is 16 and 22 gauge and I'm supposing this truck is probably somewhere around 18 gauge metal. 16 being closer, I'll go with that. I'll go very very slow with this welding and let things cool down nicely before laying another set of welds. We're certainly in no hurry here!

[Flyingvan911]

For 18 gauge steel my friend's welder is set for 255 wire speed, 15.1 volts and 8 on the inductance. Positive polarity. You can probably find a chart online for your welder. The right settings make a world of difference. I am very amateur but the right settings almost make it look like I know what I'm going. The welds are strong anyway.

[rickf]

A couple of tips. Keep your ground fairly close to your welding area. Not on top of it but withing a few feet and on the same panel if possible. Do not weld near holding magnets, you will get arc blow which will cause you all kinds of grief, you will swear you are doing something wrong when in fact it is the magnetic pull from the magnet screwing with the electrical arc. And if you are that close to your magnetic holder it will ruin the magnets anyway.