Welding Tips and Tricks

Why do I have so much undercut on my root pass?

Well they say a picture is worth a 1000 words ! - but to give members a fair chance at diagnosing your weld perhaps you could give some specifics that will effect the weld - ie material thickness - position - prep angle / land - rod type / size - current - AC / DC etc - transformer / inverter - with the relevant info I'm sure you will get some good replies.

@noddybrian
Oh yeah sorry about that .....all that info would help

I was using 1/8 6011 DC rods running at 92 amp. 3/8 2G plate with 1/8 landing and gap.

I don't know about a transformer/invert.

OK - going to admit I've virtually never used 6011 rod as it's almost unheard of here - but there are others that will chime in with more experience - may I ask why you are using a rod designed for AC on DC - can't be helping ( also are the rods quite fresh stock or been stored for some time ? )- amps seem in the ball park - my query on power source is that inverters with arc force / dig function can play hell with undercut till you know how to set your machine - some rods are more affected than others by this - for that thickness I would usually use 2.5mm ( 3/32 ? ) for the root pass as it gives more control - but I won't say either way is right so long as it works - one observation you seem to have alot of metal deposited almost completely filling the 3/8" depth - apparently if this is your root in one pass - so either you were laying alot of metal down in that pass or the prep angle is rather steep - is it possible you are moving a bit slowly trying to put down alot in one pass and the heat is building up too much for good control ? leading to overheating the edges hence the undercut ? - just some random thoughts - sure you'll get some other replies as soon as the time zones of the various members locations suit.

Are you pointing your rod upwards, not 90 degrees to the plate?

6011 were I think designed so they could be run on ac, but still perform way better on dc.

there must be some mistake in your specs, you say its your root in 3/8 plate but you are flush to the bevel in that pic

Noddy ur right about the 6011 being on AC. The school provides the rod so I hat run with it. It could be that I'm going to slow. But if I speed up just a litte it seems as if the key holes isn't fill up fast enough. Maybe my rod angle is wrong. I run about a 5 to 10 deg travel angle.

Wheresmejumer

What u r looking at is the back of the plate. I may need to do more of a upward pause bc I don't think I do that. I'll try that today.

I don't use 6011 but its similar to 6010. I like a smaller land and gap about 3/32. I shove it in and let it ride.

83amps , 1/8 gap and landing , 1/8 6011, the root from the back.

How does that look? How can I improve it?

Looks decent enough bro. Remember if you stare at the Mona Lisa long enough, you gonna find something wrong with it.

Just work on consistancy and trying to keep the same ripple spacing and sizing. See the differance between the start of the weld on the left hand side and the end of the weld? You want it all too look like the end of the weld.

But you got a good straight bead with the same profile and size the whole way down. Thats the base your looking for. Now your just working on the aesthetics. As for improving, you just gotta maintain the same motion and puddle size throughout. Remember your travel speed may not always be the same, same with your rod angle, you might have to adjust either one to maintain your puddle.