DC help

[boomer1025]

I have no doubt that many people have welded in the rain. But this raises the question of how safe is it?

What is the safe way to weld in the rain or otherwise damp conditions?

Oh it's very safe, just have to remember to always wear a depends diaper, that way if you happen to drop the stinger in the puddle your standing in, well lets say you won't have an embarrassing moment :ashamed:
Just Use alot of common sense when working with water & electric. Current flows from the stringer to the ground clamp or vise versa. Any thing in between is hot.
Rubber boots, rain suit & rubber gloves is what I would use. A big patio umbrella if it's not windy would also help, depending on what piece of equipment your working on. I used a heavy rubber mud flap to stand on already if the ground is soaked from rain. If you don't feel safe doing it, then don't.

 

[rankrank1]

darn, I have way to much free time

The Welding Handbook for Maritime Welders :thumbsup:

Nice find Rhett. I appreciate the support document from a published source as it definitely does help reaffirm my statements as it is real close.

Every document that I have ever seen has almost always showed 2/3 (or 66.6%) and 1/3 (or 33.3%) as the splits. Of course I always rounded to 67% and 33% to keep it easy for me in my head. I have a feeling that your source may have rounded a bit further to 70% and 30% to keep it at hole numbers of 10 allowing for even simpler mathematical figuring in the head calculations.

Regardless - either figure is close enough to get you in the ballpark.
My way 100 amps AC would equal 83 amps DCEP.
Your book 100 amps AC would equal 80 amps DCEP.

FWIW: I am reasonably sure my figures are correct as I have read a few welding studies documents over the years comparing AC weld current to DC weld current. Every one that I have ever read showed DCEP to be roughly 15% to 17% more efficient than AC. Using the 17% value puts the multiplier right at the 0.83 number that I always use.

If you want another document search for your free time, then let the hunt begin.

 

[rhett]

....e....

If you want another document search for your free time, then let the hunt begin.

why, noticed variables of content.../....opinion ....?.....

 

[dntfxr]

Typically, I think of it this way to help me:
AC = 50% heat into rod and 50% heat into workpiece.
DC electrode positive = 67% heat into rod and 33% heat into workpiece. (DCEP is most common polarity used and results in max penetration).
DC electrode negative = 33% heat into rod and 67% into workpiece. (rarely used, but helpful on thin sheet metal if no wire feeder and results in min penetration).

So what does it mean? In short for whatever setting that you were using on your old AC buzzbox take that setting and multiply times 0.83 for a rough starting point setting and adjust from there accordingly as needed. ( e.g. 100 amp setting on AC buzzbox would roughly equal 83 amps on DCEP).

Maybe I am a little slow, but doesn't the chart say DCEN gives more penetration and DCEP less penetration?

 

[Iplayfarmer]

Slight deviation from the thread topic... Does all this still hold true for wire feed type welding? I've been welding on some pretty light stuff lately. Can I reverse the polarity and get less penetration?

 

[deereman75]

Slight deviation from the thread topic... Does all this still hold true for wire feed type welding? I've been welding on some pretty light stuff lately. Can I reverse the polarity and get less penetration?

I dont think that works well at all. I think the wires will only run on the recomended polarity.

 

[Iplayfarmer]

I dont think that works well at all. I think the wires will only run on the recomended polarity.

My millermatic 130 has terminals that can be switched, and the book has instructions for reversing the polarity.

 

[deereman75]

My millermatic 130 has terminals that can be switched, and the book has instructions for reversing the polarity.

Thats because flux core and solid wire run on a differnt polarity. Flux core will only run on one, solid will only run on the other.

 

[Iplayfarmer]

Thats because flux core and solid wire run on a differnt polarity. Flux core will only run on one, solid will only run on the other.

The more I learn, the more I know I don't know.

Now I need to go and see if I have the right polarity for the flux core that I've been running. I love this site. Looking like a fool is well worth the benefit of knowing there may be a better way of doing things.

P.S. How is the polarity supposed to be for flux core?

 

[deereman75]

The more I learn, the more I know I don't know.

Now I need to go and see if I have the right polarity for the flux core that I've been running. I love this site. Looking like a fool is well worth the benefit of knowing there may be a better way of doing things.

P.S. How is the polarity supposed to be for flux core?

For self shielded flux core, it should be dcen (mig gun negitive) I think some dual shield flux core need dcep.