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phelum
24th Mar 2008, 08:38 PM
Recently I've been (trying to) weld bits of 16g square tube and the only way I can position the rod accurately enough is to use my other hand to hold the rod say 3" from the end. I'm using 2mm rod and 50 - 60 amps so the arc is tiny. My success rate with these welds is lousy and I find that keeping the arc short and constant and keeping the motion smooth is critical to any chance of a good weld.

The problem I have with using my other hand to hold the rod is that my hand gets closer to the weld as the rod is consumed and it's hard to slide up the rod and keep the rod positioned correctly.

Does anyone have any hints for holding the rod accurately or am I on a bad trip here ? If holding the rod is taboo maybe I could put some bricks on my table and use them as a wrist rest.

J.E. Mike Tobey
24th Mar 2008, 10:07 PM
Are you talking tig here? There are rod feeders that let you advance the rod from a distance- the feeder tube stiffens things so the rod is not flopping around. Are you doing this without gloves? I haven't had to hold a rod that far away from the bead except in those rare occasions where I have been welding in something like a cavity. I may be confused about your problem.mt

Claw Hama
24th Mar 2008, 10:21 PM
Phelum, you just need more practice. You shouldn't have to hold the rod with your other hand. Is it gal tube,painted or black? If it's gal or painted you might want to grind off the gal or paint to get a nice clean arc but stick welding on 16# is pretty tricky even for an experienced welder. You realy need mig, tig or oxy.

Grahame Collins
25th Mar 2008, 12:24 AM
Hi Phelum,
I thought we had fixed you up


Recently I've been (trying to) weld bits of 16g square tube
OK! at this point dimensions will help to establish the volume of the material. Gal or painted or black?
also what is the welding position ,flat butt or fillet ?

and the only way I can position the rod accurately enough is to use my other hand to hold the rod say 3" from the end. Theres nothing in the rules that says where you have to hold the rod but some techniques are better than others



I'm using 2mm rod and 50 - 60 amps so the arc is tiny. My success rate with these welds is lousy and I find that keeping the arc short and constant and keeping the motion smooth is critical to any chance of a good weld.

"Lousy success rate" does not tell us us what the defect is, and its what we need in order to help you. blow hole ? slag hole ? .

The problem I have with using my other hand to hold the rod is that my hand gets closer to the weld as the rod is consumed and it's hard to slide up the rod and keep the rod positioned correctly.
Yes for fillets, I slide the rod OVER the top of my gloved left hand fingers standing on edge as a spacer between bench top and electrode. An old buggered glove cutdown helps reduce heat take up and protect the good glove from damage

Does anyone have any hints for holding the rod accurately or am I on a bad trip here ? If holding the rod is taboo maybe I could put some bricks on my table and use them as a wrist rest. I thought we had you welding ok. Do what ever you need to do to brace your self.Hang on with a relaxed hold.Death grips tend to accentuate and shaky movement

If its a butt weld and a short run,bend the electrode at the shank so the stick position is semi vertical similar position( not exactly the same angle as your hand piece but a bit close)


That help ?

Grahame

phelum
25th Mar 2008, 06:30 AM
Oops, my original post is missing lots of details.

I am AC stick welding using 2mm type 12 rods. The square tube I am welding is 32x32x1.6 and is painted but bare metal near the welds.

I thought that 1.6mm is okay for stick welding. There are some butt joints (all downhand) and welds here have been okay. Most of the joints are where the end of one pipe meets the middle of another. Here I have 2 internal corner fillet welds and 2 open butt welds (gap approx 1mm). For the open butt welds I have to angle the arc toward the arris of the through piece of pipe or it will blow away the end of the other pipe. I can just get away with this if I have a very short arc and precise positioning. The only way I can do this is by holding both the stinger and the rod near the weld end. It is hard here to get the weld bead to wet both sides of the joint without blowing away the end of the pipe.

The internal corner fillet welds (all have one horizontal surface and one vertical) are the worst problem. If I get it right (about 1 in 20) I get a nice neat little fillet but generally I will blow a hole in the pipe end or the bead will stick to only one side. Again it seems to need a very short arc and smooth motion and I just can't do this if I am holding just the stinger (even with both hands).

I will keep practising and try resting the rod on a glove rather than holding it. I also think that next time I find some thin-walled RHS I will leave it there rather than taking it home for welding practice.

Grahame Collins
25th Mar 2008, 08:09 AM
Hi Steve,
The way to go is start with thicker material.When you perfect your technique you will know it that defects (later in the thin stuff) are not due to your basic technique.
Move to the thin stuff only when you happy with the outcomes on the thick stuff. personally I would be practicing all the positions first on heavier gauge and working the light gauge after.

Mind you theres a whole raft of new problems due to less heat dissipation.Welding is truly about physics.

A welder needs to be able to weld anything in any position. Moving out the basic flat positions take some practice. Its about bracing oneself and remaining with a relaxed grip on the hand piece.

With your 32 mm pieces I suspect theres not enough metal volume to dissipate the heat build up. I would tack up each corner first, so the end of weld bead has some thing thicker than the 1.6 thickness to finish on. The weld bead is narrow but its ok to weave the rod slightly to widen the pool.,and bridge the joint.
Grahame

phelum
25th Mar 2008, 06:48 PM
The way to go is start with thicker material.When you perfect your technique you will know it that defects (later in the thin stuff) are not due to your basic technique.
This is a very comforting remark because I had a pig of a weekend welding the thin-walled tube. It is far more difficult than I expected. I managed to fix some of the welds today by grinding and re-welding so I will quit now and worry about it later.

I will hunt down some thicker scrap tomorrow and will try the vertical-up method you provided. No doubt I'll be back with more (stupid) questions soon.

Yesterday I tried a Satincraft rod on some of this fine work. It wasn't any better than the rods I am using but what amazed me is how it needed a much longer arc to avoid freezing. Maybe I am getting used to a short arc.

Grahame Collins
25th Mar 2008, 07:25 PM
what amazed me is how it needed a much longer arc to avoid freezing. Maybe I am getting used to a short arc.

Hi Steve,
You are getting used to THE SHORT ARC and thats what (dare I say it ) -real welders use.

The Satincraft lovers won't agree but I say a longer arc gives rise to slag inclusion problems. Longer arc length give higher voltage and lower amps.This translates to a higher heat input Ie burn throughs on thin stuff and less
penetration on thick stuff.

The fact that you can recognize the subtle difference in arc performance between the two electrodes speaks volumes for you. being capable of that you are well on your way to being an experienced welder.

You are going to have bad days ,we all do, but in the main you are observing,understanding and making necessary changes.Come back to it after a few days with a fresh view point and away you go again.

No questions are stupid.You reckon you have strife, then you should see me trying to deal with learning a CAD programme. Year 8 kids can do it but I don't get IT- I am a problem dinosaur from the drawing board era.

good on Ya Steve
Grahame

Good one mate!

phelum
31st Mar 2008, 05:22 PM
You are getting used to THE SHORT ARC
The precision required to keep a short arc is a bugger for shaky old fools like me so I made a lightweight baby stinger so I can hold the rod if it is long or hold the stinger when the rod is shorter. Generally I use one hand to hold the rod/stinger and the other to support the cable.

I know this is cheating but it is working for me and since I can maintain the arc better I can watch the pool and concentrate on getting it right. When I get better at welding I probably won't need the lightweight stinger.

The cable is 8g power cable from Jaycar and I've soft-soldered a 2 screw connector to the end. The amazing thing is that even when I burn a rod right down to the end the connector doesn't get hot enough to melt the solder. The connector and cable end are now covered by a short length of 5/16 brass tube which provides a handle when using the last few inches of the rod.

This setup is only designed for 2mm rods and say max 80 amps. A big version of the attached picture is at http://phelum.net/temp/P1020722-1280.JPG.

pipeclay
31st Mar 2008, 09:12 PM
Excuse my ignorance but where does the hand piece attach.

phelum
31st Mar 2008, 09:20 PM
Excuse my ignorance but where does the hand piece attach.
The upstream end of the cable has a 5mm OD sleeve that I clamp in the standard stinger. Unfortunately this is end on in the picture so it doesn't show.

Grahame Collins
31st Mar 2008, 11:58 PM
Stinger,
Stinger. Really now Steven! have you been hanging around those yank welding forums for a bit too long ?

The yanks call them that cos some of them get stung (get a boot) from them. Also happens to dumb Aussies who weld in the damp grass wearing their safety fongs. That was after the spatter stuck to my foot.
It doesn't hurt much more than holding the mower spark plug-while its running.
Also helps HS students remember not to lean on the work bench.
A bit of insulation on the bare handle may help that.
Stinger indeed!

phelum
1st Apr 2008, 02:14 PM
Stinger,
Stinger. Really now Steven! have you been hanging around those yank welding forums for a bit too long ?
Damn, the style council has caught up with me already. I knew it was a mistake to read that Lincoln book and pretend I understood it.

Improvement #2 for the holder is an insulated handle using a piece of PVC tube. Thanks for the idea.

I have to admit I often wear safety fongs when welding. It's okay except when I get a bit of slag between my toes. I hope you don't wear thongs when mowing your lawn like I do. Also, never ask for thongs in England or people will give you a filthy look or laugh at you.