Penetration

[Main]

Need to settle a discussion about SMAW.

What has better penetration, DC straight or DC reverse?

[cope]

Charlie, this is straight from Hobart's site:

5. Penetration: DCEN ‹ Least penetration, AC ‹ medium (can be more spatter also), DCEP ‹ most penetration.

[dseman]

Charlie,
To add further info.....
Take any SMAW rod and strip all of the flux off of it. You basically now have a mild steel rod. Light that baby and burn it with the same amperage, arc length, and travel speed in DCEN and DCEP. You'll find that DCEN has higher penetration, and DCEP has higher deposition. Now try something like a 6010 rod (with coating) in DCEN and DCEP. DCEP has higher penetration now right? Why is that? It is because of the flux's capability to alter the arc characteristics. I've seen this question raised so many times by guys who swear that because tig welding has higher penetration on DCEN, they think SMAW should also. Well, now you know the reason why DCEP has higher penetration on SMAW and DCEN has higher penetration for TIG. There are differences in the electron emission of a tig electrode (since it is doped to alter the work voltage), compared to a bare filler rod in a smaw electrode, but the experiment usually proves the point.

-dseman

[Main]

Thanks gentlemen. Thats just the information I was looking for and then some.