Welding question

[speedsport]

Using 200A AC/DC Tig/Stick inverter welder. How to determine when to use AC when to use DC?. Using 6011 5/32 Lincoln welding rod on mild steel, what amps would you expect to use?

[macona]

Always use DC. AC is for aluminum tig.

5/32 will be somewhere around 140 amps.

[speedsport]

always use DC for welding mild steel?, then why can you buy a AC/DC stick welder?

[NickH]

Because metal is not always plain old mild steel,
funnily enough
Nick

[JoeFin]

Check the Lincoln Knowledge base

http://www.lincolnelectric.com/knowl...icles/list.asp

Kinda of like an infomercial you 'll have to weed through to get some good information but they do have lots of good information.

As for your welder sounds like you got a good 1. I use a variety of AC/DC and TIG welding depending on the job.

As for your 6011 on mild steel feel free to use AC or DC 30 - 60 amps depending on the thickness of the steel you are welding

[pcarpenter]

I think the reason you got the "always use DC on steel" advice was under the assumption you were tigging it.

With stick welding, I generally find that I get a smoother weld with DC with any rod for which it is an option. AC tends to offer deeper penetration, but does not seem to produce the same quality weld otherwise. Its been a couple of decades since my welding classes, so I don't even remember the general cases under which AC is considered desirable.

All my DC experience has been with welders I don't own. I took several semesters of welding in high school.....almost 25 years ago. I only own an AC buzz box (beside my MIG welder) personally. I would probably use stick more if I had DC as it seems to make for better looking welds. As it is, if I don't need to weld something fairly thick (beyond the abilities of my 170A MIG), I end up using the MIG (which is inherently DC).

Paul

[R W]

Always use DC. AC is for aluminum tig.

5/32 will be somewhere around 140 amps.

Amps for a 5/32(8gauge.4mm) rod would up to around 180 depending on the
thickness metal of the steel.Could even go higher on thick sections.
AC can be more suitable on small jobs where thin material is utilised,as it
dosn't get the job as hot as DC. A 1/8 or smaller rod with a lower amp setting
is easier to use in this situation, a 5/32 at 140 amps will be hard to start in
many cases.

[macona]

In general even in stick if you have DC use it. I prefer 7018 for pretty much anything.

[John R]

What about reverse DC ? When is it to be used ?
John R

[macona]

That can depend on the rod. You can look at the manufacturers specs. 7018 runs reverse polarity. 60 series usually straight. Cant remember for sure. I avoid stick like the plague.