Hey all,
You might have heard this question already a lot and are tired of answering it but I can't help to post it here. What techniques do you use for open roots?
I'm in welding school right now and our teacher told us to literally push the rod into the groove and kind of bend it so the tension from the bend pushes the rood into the groove. It seems to work out for him this way and some of my classmates but for me it doesn't. I can't see anything, not a keyhole not even a little bit. I get a lot of toe nailing with this technique so it's really frustrating. What I started doing is ramping up the amps and the DIG (85 amps, 80% DIG) and just drag the rod with barely touching the bevels. Works pretty well for me in the 1G and 2G position but vertical down and overhead I'm struggling to get enough reinforcement on the root. The 4G almost leaves suck back where the root is below the surface. Same with the vertical down, the fast travel speed doesn't give me enough time to deposit enough material and the gravity just pulls all the crap down which makes me go even faster. I tried lower settings to prevent the suck back but then I won't get enough penetration.
As for the setting and joint fit up, we use 3/8 plate, 30 bevels, 3/32 root face and 3/32 root opening, 1/8 6010 @ 85 amps and 80% DIG.
I just feel like I'm doing something wrong but can't figure out what. If you could help me out with some tips and tricks, what techniques you are using or if you tell me what I' might be doing wrong that would be awesome!
Thanks,
Scharrer
The industry you work in will typically dictate their preference with regards to uphill or downhill vertical progression. The oil patch and cross country pipeliners seem to prefer downhill progression, while those working in the power and process piping typical prefer uphill progression when welding vertical grooves. Vertical downhill is verboten in the structural steel arena. You might see a structural welder using downhill progression to repair undercut, but then, why is he getting undercut. Welder? Really?
If you are welding using downhill progression, the chances are you are using either E6010 or E6011. There are a few that will use E7018, but that is a rarity from my experience. With either E6010 or E6011 you burn hot and travel fast to stay ahead of the slag and molten metal. It employs a drag technique and very little if any weave or whip on the root bead. If you are welding vertical uphill, a little whip in the root to control penetration and weave beads for subsequent layers.
And then it involves a lot of practice to get the feel for what's going on with the weld pool. Some people catch on quickly, others have to work at it to perfect the technique. Oh yea, technique is something you work on the rest of your career.
Good luck - Al
I see, I kinda looked for other techniques because I got a lot of toe nailing when I did the push/drag technique. When doing vertical and I have the choice I will do uphill and just whip it. What manipulation would you do for a 4G position?
Scharrer,
vert down and vert up are two different techniques. Your instructor is correct. Vert. down, you push the rod in until you almost snuff it out. It is a technique that is learned by much practice. The other positions including 3G-Uphill, and 4G, you use a technique called key-hole. I/8" gap with nickel to 1/8" land with 1/8" rod. Most of the fire is on the inside. You oscillate and keep a key-hole going the whole way. You end up with a flat weld on the bevel side and slightly above flush on the other side. You know your technique is wrong when most of the weld is on the bevel side. Attached is a picture of one that looks fairly good.
Thanks, my instructor recommended to do the push/drag technique for all positions. It sometimes worked for me and sometimes it did not. Got a lot of toe nailing which really frustrated me. The whipping technique works better for me. When doing the 4G is there something particular I have to pay attention to? Because I often didn't get enough penetration on the root side.
In the overhead position my roots look about the same than the one in the picture. Except there is just barely reinforcement if any at all, sometimes even concave and I somehow manage to get undercut on the toes of the root. I suspect it is because I'm not pushing the rod enough into the groove which then often leaves me with toe nailing. I think that you're correct and it's just gonna take a lot of practice but still wanted to get some more opinions and see if any light bulb light up
Scharrer,
The one thing I want to stress is using the key hole oscillation method typically does not bring under cutting in the 2G , 4G or the 3G up-hill positions. Dragging the electrode with out any oscillation typically is what causes that in my experience. Down hill welding by using the dragging technique is best. If you are getting undercut in that position using that method it could be arc blow, excessive high-low on the fit-up or a grounding issue. Of course this is my opinion based on my experience and as a welding instructor for 8 years with FD.
Thanks, I think I just need more time under the hood. After all I only welded about a dozen open roots. When you're oscillating are you going up the bevels a little bit or do you do your oscillating just over the root opening?
I have used the technique you speak of along with keyhole by whipping and even a slight side to side technique when the gap gets big.
For all of them, the joint configuration, amperage, and arc force all play a part. My preference on the overhead section of a pipe is to have the electrode pushed against the groove faces tightly. With a set of factory 30 Deg bevels then it is hard to get deep enough in the groove sometime. In that case, I turn up the amperage and make a bigger keyhole (All methods produce a keyhole for the most part). When I whip back into the area of the keyhole, I make sure my arc is very close. If I am getting ANY sparks outside the pipe, I am probably not getting the root in there with any amount of reinforcement.
There are many ways to put the root in. I have my students work on "open roots" by welding 1/8" and 3/16" flat pieces until they can get a decent root in them by all three methods. Sometimes I have them fit them with various root openings which may force them to stop and change settings or change techniques "on the fly".
Without observing someone weld and even watching the weld, it is difficult to "armchair quarterback" welding.
Thanks for the response! Is it common to get toe nailing when doing the push technique? I'm struggling with it, even though I really turn up my amps and DIG (~80 Amps and ~80DIG) I still get toe nailing quite a bit. Would you turn up the settings even more?
I'll see if I have an old root weld lying around somewhere.
I have experienced extreme toenailing with 6010 occasionally and sometimes it was the result of arc blow more than anything. Another factor that can make it occur more often in a narrow groove angle or groove faces being rounded.
If the joint fitup can take the added amperage you can almost NEVER go wrong with turning it up.
Have a great day.
Thanks for the response, I might try a bigger root face and opening. Might help to keep the toenailing under control. We do a 3/32 landing and root opening so I'll just do a 1/8 opening and landing. We'll see what happens! Thanks for the tip!
It was more the groove angle and not the root opening I was speaking of though they both work together to allow/restrict access to the root of the joint.
Topic Welding Industry / General Welding Discussion / Open Root Techniques for Vertical Down and Overhead
