Learning Arc Welding

[Paul.]

Then, dont just do lines of weld on the plate, do lines of weld to build up a pad!. Each run of weld gets laid next to the previous, then de-slagged and wire brushed.

You have to build up a complete layer of weld without slag inclusions. When you've covered the plate, turn it 90 degrees and do it again.

This will teach you: how to start the arc, how to keep a straight line, how to merge welds, how to do a half fillet/half butt (sort of), plus give the basic practice of maintaining arc length and consistency.

It will also give confidence in performing a single, but basic technique.

When I used to teach arc welding, that was exactly how the first exercise was carried out, we then used to cut through it and macro etch, to show fusion into the plate and inter run fusion, its a good confidence builder for beginners, and teaches basic electrode manipulation before moving on to joints.

 

[HasBean]

I'm in the process of an evening class doing an ABC level 2 in MMA (though thanks to work I've missed the last 4 weeks )

Started off doing a multilayer overlaping pad, say 3" square for 5 or 6 layers using 3.2's (That's then cut and polished for the dilute nitric)

After that was 90 deg open corner on 6mm, 2.5 root, 3.2 fill & cap, then again on 10mm (2.5, 3.2, 4 this time)

Then lap joint, 6mm 2.5 root, 2.5 cap (missed the 10mm )

T-Fillet 6mm, tack both sides, 2.5 root, 3.2 fill and cap (I think) or three 2.5 stringers (again missed the 10mm)

Butt joint (yes you've guessed it, 6mm V prep 2.5 root and then ?????? dunno as I haven't done it yet
Suppose 2.5 root and some 3.2 stringers?

I've probably got a lot of this wrong from memory but the joints certainly went in this order.

Next up we go horizontal and then vertical (first lot of exams in February )

Paul

 

[Paul.]

Similar format as the C&G and EMFEC 165 I suppose then, once all the individual joints had been mastered, the exam piece was a small fabrication made from 6mm plate that included all of the joints, that was assessed for accuracy of fabrication then cut up for destructive testing using macro etch, nick breaks, face and reverse bends. there was also a cast iron test, single vee butt using Nickel based electrodes, and a pipe welding test,

 

[malcolm]

Brilliant. We've got an arc welding tutorial for complete beginners in the thread now. I'll organise the necessary bits and pieces and give it a go next week. Expect photos of some very bad arc welds.

 

[runnach]

All very good replies to date Malcolm. Re: Snowies about all parameters, up the amps, up speed of travel is very true for an experienced mma hand. Si comments about "building up a pad" this is the way I go when I have new learners.

I have a few exemplar MMA pieces (all 6mm lcs plate) various positions, including pad, I'll try to remember to take my camera to work next week for a few pics, I can forward these to you, you may want to add pics to tutorial, may go a little way for others to view the outcome of having selected good MMA welding conditions.

Cheers............

 

[shenion]

Just looked up the manual on the Dialarcs. They don't have a hot start feature (also helps rod from sticking), so learing with a higher current is a good idea.

 

[dutchman]

One more thing about arc length:
as you often can not see the arc, because it is covered in smoke, it really helps to listen carefully. Hissing and spitting means the arc length is too large. If it goes silent, arc length is too short. If it sounds nice and crispy.... you've got it right.

 

[Drains]

One more thing about arc length:
as you often can not see the arc, because it is covered in smoke, it really helps to listen carefully. Hissing and spitting means the arc length is too large. If it goes silent, arc length is too short. If it sounds nice and crispy.... you've got it right.

Ah, but if you're welding an open butt joint, it changes again when the penetration is right - you should hear the arc coming out the other side!

 

[dutchman]

But it would still be a crispy cracking sound coming out of the other end of the open butt joint wouldn't it?
I am no expert on these open butt joint things, hence the question..

 

[Paul.]

You can hear the arc blow through, its a different sound to the the crackle of a fillet weld, If welding a tube or box section you can hear it echoing along the tube.

 

[malcolm]

I have a few exemplar MMA pieces (all 6mm lcs plate) various positions, including pad, I'll try to remember to take my camera to work next week for a few pics, I can forward these to you, you may want to add pics to tutorial, may go a little way for others to view the outcome of having selected good MMA welding conditions.

Cheers............

I think I've figured out what you meant - I wasn't thinking about writing a tutorial for everyone else. Tutorial for me was what I had in mind. Though this thread should also be useful for other learners.

Would definitely be useful to see what it is I should aim at if you have the camera handy.

 

[runnach]

Oops, I got the wrong end of the stick Malcolm, I thought, your thoughts was another tutorial to add to what you already have on here!

No worries tho, I'll rattle off a few shots for members to peruse at.

Cheers.....

 

[irondarren]

Its actually nice to keep the arc welding threads alive, as arc or mma welding is the cheapest entry into welding.

the first pic is of a vertical up weld on arc, with slag still intact, it looks awful. second pic is with slag removed, it does look better but not as it should do, through lack of practice on my part. the third pic is a vertical up using mig (im well practiced in mig )

 

[Sparkey]

Brilliant. We've got an arc welding tutorial for complete beginners in the thread now. I'll organise the necessary bits and pieces and give it a go next week. Expect photos of some very bad arc welds.

Think i might join you on this adventure....
like Malc said: expect pics of some veeeery bad arc welds!
I'll try have a go at the overlapping pad....any more tips and hints guys before i make a complete mess of this??
(besides the advice of wearing goggles when you chip off the slag, i've learnt that the hard way already...ouch!)
So for starting the arc properly you tap and then lift it off the workpiece? (just slightly)

 

[malcolm]

I've been playing at arc welding this afternoon. Many thanks to weldequip for donating some lovely Murex 6013 rods for the arc weld off. We've got them in 2.5mm and 3.2mm and hopefully there will be some left by then. And also special extra thanks Steve for also donating an electrode holder for the Miller Syncrowave and a surprise couple of lenses for the Eyetech.



Seems I'm also spoiled by the Miller. I took the advice here and over-amped the rods to start with. Unfortunately I got confused over start current on the Miller and sent about 300 amps through them to start with.

Switched start current off. Starting is easy with the tap method, and even getting it wrong the Miller will still maintain an arc 25mm long while I settled back in position! Quite quickly ended up at about 120 amps for 3.2mm rods DCEP on 6mm sheet. Here's one with the slag still attached:



Found it took a bit of practice to maintain direction, rod angle, and a fairly small gap. Damned rod kept getting shorter all the time!

I'm not so good at ending the welds just now. After this weld I've started trying to leave the rod in one spot for a while to fill up the hole. That's working better, but is there a technique for this?

Here's the weld with the slag removed:



Had a bash at a joint in 6mm sheet. Not a well prepared joint - cut 2/3 through with a thick cutting disc then broken apart. No V or anything like that.

There's a fair bit of stopping and starting and a few different settings, speeds etc. I wasn't happy that the weld was so wide. Penetration was just touching the far side. Not like MIG at all which tends to feel deeper and narrower. Is it normal for 6013 rods? I've read they are low penetration rods, so perhaps better prep would have been the thing to do.

Actually the weld looked a bit narrower with the slag removed:



Finally onto the weld pad. Managed 3 layers before getting bored, but I've not sectioned it. Here's the first:



Any thoughts or suggestions? I'm thinking maybe I'm running a bit cold apart from the pad which was warming up nicely Are arc welds wider and flatter than MIG welds as a rule?

Otherwise for my next trick I'll try to practice a bit with properly prepared butt joints, and maybe fiddle with 3mm if I can find any lying around. Then onto one of those corner joints.

 

[malcolm]

Think i might join you on this adventure....
like Malc said: expect pics of some veeeery bad arc welds!

So for starting the arc properly you tap and then lift it off the workpiece? (just slightly)

You should give it a go. I'm enjoying it, and the rod is much easier to control than I thought it would be. You'd think being 315mm away from the work would be a problem but it's not really.

I've been tapping the end of the rod and lifting it up quickly. Other option apparently is to scratch the end of the rod against the work like a match and lift it up quickly. Tried that on some thinner stuff that I was under-amping and it worked better for that. Trick either way seems to be movement.

 

[Sparkey]

OK i will give it a go (again)!
Got another question: i already tried lots of times to take photo's of my welds (mig welds too) but i can't seem to get them as clear as your pics....
How do you do that? or maybe my camera's just crap?

 

[malcolm]

Your camera is probably crap. I have a Fuji S8000FD with macro and image stabilisation bought especially for this sort of thing. About £150 which isn't too bad, but it's bulky.

Real trick is to use natural light and move the work around until it looks nice. Then rest the camera against something to stop it from moving around and blurring the image. I used a broomstick to support the camera for the photos but some photographers use a tripod.

 

[Sparkey]

Oooh that's it!! i forgot to use my broomstick!!
Thanks malc!

 

[Woody.v8]

The trouble is when you get bitten by the arc bug there's no going back!!