Got any tips on keyholing for open root V groove root passes?

[moya034]

I've started on doing open root V grooves at school. The teacher there is excellent, but I always like to hear other people's opinions and ways of doing things as well, especially on the more advanced topics.

He has me starting with 3G, 1/8" lands and gaps, with 1/8" 6010 electrodes.

I'm specifically interested in how you guys like to set your heat and control the keyhole size for the root pass.

TIA! ;)

[OldSparks]

Have you done a search on here and the other welding boards? You'll find a variety of techniques. Most problems arise because of trying to run too much heat before you have the experiance. You can calm things down by going with about 65-70 amps and long arcing to preheat. Strike your arc and then hold back and long arc so no metal is deposited. Raise up about an inch and then lower to starting point. Should take a 2-3 seconds. Now approach straight on and start your puddle, walk up slightly and push through for full penetration. Moving up slowly, I twist my wrist slightly maintaining keyhole. I judge my travel speed by trying to keep a maximum of 1/8" of bead "tinted pink" colouring under the arc. If/when the keyhole begins to enlarge, start a slight 'v' whip.

[moya034]

Most problems arise because of trying to run too much heat before you have the experiance.
You can say that again! Thanks for the response OldSparks.

Since I posted the thread, I've had quite a bit of time to practice the open roots, and have gotten fairly good at running them with 6010 in all positions, 2G, 3G, and 4G. They don't even have us do 1G at school, I suppose it's too "easy" if you can do the other 3 positions.

I find if I have my heat set right, that I can keep a keyhole just shy of a 1/4" diameter, and alternate between quick pauses to deposit metal, and a really short whip. Unless my keyhole get's too big, I don't have to whip outside of the keyhole.

If the keyhole becomes too small, I pause longer to open it up, and if it gets to big, then I whip farther to close it up.

I will probably start pipe welding sometime late next week, so I'm looking forward to trying open roots with that!