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Up Topic Welding Industry / General Welding Discussion / "HELP" with root pass
- - By arc_74 Date 05-25-2008 01:24
I have to do a 3g open root test on a 10" x 5/8" plate for a job i'm trying to get. It has to pass an x-ray. Can use 7018 or 6010 for the root. I can't seem to keep it consitent all the way with either rod. Can really use some tips and pointers!!!!!!!!
Parent - - By swsweld (****) Date 05-26-2008 02:31
My 6010 experience is with pipe but I will try to help. Maybe some better qualified will help too. I think the 7018 is the more difficult of the two.
I suggest a 1/8" gap and a nickel land. Make sure to use strong backs or put good tacks at the top and bottom so the gap does not shrink while welding. Try your heat at 70-75 amps. It could take more but it will depend on the machine. You MUST create a keyhole immediately. Then use a slight whipping motion w/the rod. Oh yea, use a 1/8" rod. E6010+++ by Lincoln is the best. Whip the rod vertically to keep the keyhole. Don't lose the keyhole. The tip of the rod must be buried at the root opening. Almost place the tip beyond the root opening. Do not long arc or you will not get full penetration.
If the keyhole gets too large you should reduce the amps and vice versa. Taking longer or shorter whipping strokes to alter the keyhole will also work.
If you are allowed to grind (feather your stops) to insure better starts.
Before the hot pass, grind the face of the root pass down to reduce the risk of trapping slag on the hot pass. If you grind too much you will blow through on the hot. I run 7018 3/32" on the hot pass and not too hot. Maybe 80 amps. That's why I use 1/8" on the root to get more deposition on the root.

Good luck with the test. Let us know how it turns out.
Hope it is an uphill test or I just wasted our time
Parent - - By arc_74 Date 05-26-2008 14:44
Yes it is uphill. I havn't had any problem getting a keyhole, but as I go on it wants to open to much and it seems I keep fighting it to keep it closed leaving a sloppy looking bead on the backside. How fast  of a whip do you use? and how long of a pause? I havn't used 6010 in a long time. Thanks for the good advice....
Parent - - By ibeweldingsum (***) Date 05-26-2008 17:01
sounds to me like you have to big a gap and to much heat. 6010 5p+ is a very good bead rod but you need to gap it one size rod smaller than the rod your going to use for your root pass. say 3/32 gap for 1/8 rod so on and so forth.
Parent - By cwf07 (***) Date 05-27-2008 00:25
ibeweldingsum
When you are welding your root pass 5p+ down hill are holding it straight or what degree angle are you holding and if you are holding in a angle are you pushing the rod hard against the pipe to were the rod is bending and are you wipping the rod are draging it. Sorry to ask so many question I am trying to get into more pipe it hard to know what to do with out having any body to watch that does pipe welding for a living.
Parent - - By swsweld (****) Date 05-27-2008 00:59
arc_74, I agree with ibeweldingsum on the solution. If your keyhole is getting too large you can reduce the amps and or reduce the gap and or increase the land. Another tip is to tilt the rod angle down(increase angle) to reduce the penetration. This can be done while welding to fine tune the bead instead of stopping to change the amps. Also if you need to increase the keyhole you can tilt the rod angle up towards 90 degrees and you will enlarge the keyhole and get more penetration if all other variables remain the same. i.e. depth of rod, whip technique etc.

If you are rusty or not too experienced w/6010 you may consider 3/32" rods for the root and reduce your gap and land slightly. Smaller rod will be easier to control.

The length of the whipping stroke should be approximately 1 1/2 times the electrode diameter or less. The rod should pause at the bottom of the keyhole long enough to deposit metal and raised up enough to keep keyhole size consistent and allow the root time to cool. Pausing at the top of the stroke will allow more cooling but will possibly enlarge keyhole so be careful.
Asking how fast to whip is sort of like asking how do you weave. Every welder has their own style that they use. I would say that a complete cycle for me would be one second. But I change while welding if I need to. Gap widens, closes, keyhole gets too big, small, etc.
I think 60/40 ratio would be close. Pause at bottom 60% and raise 40% Adjust while welding to maintain penetration and keyhole.
Of course all of this requires the correct amperage. If you are fighting the keyhole cut your amps down. It's easy if things go well but it's a lot to digest when it's falling to pieces in a test booth.
If you can practice before the test to get a couple of good roots in that would help. If not just try to relax but have in your mind what to do IF this or that happens. After the root, keep it clean. Remove all slag and porosity if you have any.
Hope this helps and doesn't confuse as I sometimes ramble on incoherently for hours...

Best of luck on your test.
Parent - - By arc_74 Date 05-28-2008 00:37
I ran 3 practice tests, and they all started out well but each one started closing as I progessed up the plate. I had a pretty good tack(so I thought) and it closed to the point that I couldn't keep it open. Any "failsafe" way to prevent that from happening? I'd hate to fail the test because of that.
Parent - - By swsweld (****) Date 05-28-2008 01:23
The tacks should be at least 1" long. You can put a hot pass on the tacks also.
I suggest putting a strong-back on the back side.
Place two flat bars(2"x8"x1/4"is plenty big) or plates horizontally about 2" from the bottom and 2" below the top. Notch the plates out at the root area so the root will not fuse the plates. Use a torch or grinder or hot rod it. Just tack one side (top side or bottom side)of the plates/bars so you can remove them with a hammer.

You could put more tacks in the root opening, but I would use the strong-backs instead to prevent unnecessary tie ins.

Strong-backs will work. Put three in if you want to.

Good luck with it.
Parent - By jrw159 (*****) Date 05-28-2008 02:31
:-)
Parent - - By arc_74 Date 05-28-2008 22:58
Well I took the test, and I was pretty happy with the way it came out. Your tips definately made a difference.I had good penetration all the way to the top and the rest of the passes went pretty smooth. I put some good 1" tacks and welded some pretty hefty plates on the back.... Needless to say, it didn't budge. So "THANKS"... Now I have to wait for "the phone call"(fingers crossed).. Thanks again for the help guys.
Parent - By jrw159 (*****) Date 05-29-2008 00:23
I wish you the best of luck buddy.

jrw159
Parent - By swsweld (****) Date 05-29-2008 00:46
We'll keep ours crossed as well.
All the best.
Parent - - By arc_74 Date 05-31-2008 14:42
I guess everything was cool with the test but now they want me to come back and do a fluxcore test. Vertical double bevel and a horizontal double bevel. I'm pretty sure about doing the vertical but cant quite remember how to go about the horizontal (push or pull?). Both are x-ray. I haven't run fluxcore in about 8 years. I'll take any thoughts you guys want to throw at me. Thanks.......
Parent - - By swsweld (****) Date 06-01-2008 01:11
That good news.
My last real experience w/FCAW was about 6 years ago. I ran some slick beads but busted the bend test.

An old-timer in the shop noticed I was pushing the puddle slightly and suggested I pull instead.
I did and passed the retest.
There are many better FCAW welders in here than me. Hopefully they will pitch in.
Parent - - By arc_74 Date 06-03-2008 14:31
The test is a horizontal double bevel. I'm not sure if they are gonna give me a test run or not. If they don't i'm not sure whether to push or pull the beads and how quite to attack to root pass.
Parent - By Stephen32 (*) Date 06-04-2008 18:12
Since it is a double bevel, I wouldn't worry about pushing the bead all the way through. Put your bead and two more passes on one side then grind the bead from the back side until you see sound metal. Then put your weld in. Next put two more in and then fill it up. As far as push or pull, I try to put just a slight push for horizontal. Maybe 5degrees or so. You probably know this but fill from the bottom to top, no whipping. That is my way of doing it. I also have just got done with 9 PQR tests on flux cored.
Parent - - By arc_74 Date 06-07-2008 00:21
Well I managed to pass all the tests. It was a stick vertical 3g, stick horizontal, fluxcore vertical and horizontal. All had 2 pass x ray and a bend test. I wasn't really 2 worried about the fluxcore and ironically I struggled with the horizontal. It still managed to pass. Was a tough test. I was the only one in the group who passed. I just have to wait for there offer now. Thanks for all the tips, it made a difference!!
Parent - By swsweld (****) Date 06-07-2008 01:44
Good job arc_74 and best of luck to you. Hope it is a generous offer.
Up Topic Welding Industry / General Welding Discussion / "HELP" with root pass

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