Welding currents.

The question is: What is the general rule for AC, DC+, and DC- welding?

DCRP= electrode positive (the rod holder) or also called reverse polarity
DCSP= electrode negitive or also called straight polarity

A/C has no polarity.

Lincoln 6010 or P5, DCRP for clean mild steel,

Lincoln 6011 DCRP for clean mild steel
AC or DCSP for glavanized 1st choice

Lincoln 6013 AC.

If welding flat or horzontial, Lincoln 7024 or jet rod used DCRP. They don't call it jet rod for nothing as it welds very fast and flat.

It's the rod flux that determines the first choice or only choice of type of welding current.

The rod numbers are defined as follows: Example 7018
First two numbers is the rated tensil strength in thousands
70/18 would be 70,000psi tensil strength

Third number is weld postion 1= All positions, 2= flat & horzontial postion, 3= flat only
70/1/8, with 1 being all welding positions.

Fourth number is the type of rod flux coating. there's ten so I will not list them all.
701/8= 8 being a iron powder coating

T_Bone

Bill

Any rod can be applied as a single bead or weave bead depending on joint design and position.

As for weave technique, I like to use the straight accross like a zig zag. Start at one edge then move quickley thru the center, then pause at the oppisite side to fill the corner pocket to prevent undercutting, then back quickley to the other side moving up or forward 1/2 of the rod diameter. This makes a flat smooth bead. The slower you move thru the center of the weld face the more extended the face will be. Move too fast from the corner pocket and undercut will result.

I really don't like 6013 as a rod but it does work well on AC. I fell in love with 7018 as it's very verstile once you learn to run it. Weld with a little hotter setting than you normally would and it will produce great results. One mistake most welders make with 7018 is welding to cold with to wide of a arc length. Weld hot and close and it'll soon be the only rod you want to use.

I may have to explain the weave I use in a different way as it's difficult to describe in typing.

T_Bone

Thanks for the comments.

I dream of a Miller Tig machine!

Depending on the rod manufacture, 7018 is made to run on all currents. Some of it runs better on certian currents than others and never hurts to try different welding currents than what the mfg spec's. I had some Hobart easy start 7018 that wouldn't run worth a darn on DCRP but did run better on DCSP and not worth a dip on AC and the rod was preffered DCRP by the mfg. In any event it wasn't Chemtron 7018 and couldn't hold a candle to Chemtron.

Glad I could help

T_Bone

Thanks for the info on the boat. I'm not really finished with the project. Can I get more details on the chill bar?

And Bobby also uses Propane in the place of Acetelyne. Comments?

Propane/Oxy burns at 3690F and Acetylene/Oxy 5420F I haven't compared prices lately so can't make a comment other than I don't really care for propane , mapp or natural gas as a cutting fuel. It does great as a preheat. For what little I cut here at the house, I'll stick with acetylene. We did a cost study for commerical use years ago and found although the cost of fuel was lower, labor costs far exceeded the fuel savings.

T_Bone