Arc welding 0.8mm sheet steel

[metaljoiner]

Sorry GeorgeB, I was still talking about the Kel Arc car body welder! , but the thread moved on to your spot weld project, Did you find the Kel Arc car body welder really noisy? I did , and also referring to those test weld pieces you posted, When I had my Kel Arc welder, the welding looked exactly like yours I could not progress any further it it, could not get a straight line of weld, the Welding rod would dance about too much.

Good luck with your spot-weld project, I would like to build a spot welder, but the wife would go mad with me blowing the fuses round the house all the time.

 

[GeorgeB]

>Sorry GeorgeB, I was still talking about
>the Kel Arc car body welder!

MJ - That's a relief! Bangs from high power spots sort of made sense because of the bang you can can get when a TV or something goes wrong, shorting the mains, but I hope there's no spot welder noise after all.

>Did you find the Kel Arc car body welder
>really noisy?

No, I can't say I noticed much noise at all! It does vibrate but I hadn't noticed much noise.

>When I had my Kel Arc welder, the welding looked
>exactly like yours

I had better results in the middle of a sheet, rather than joining edges, at least appearance-wise. But the Kel Arc still seems to have a contribution to play in helping to join thin sheet without blowing holes. The jury is still out as far as I'm concerned, even though it does do what it says on the tin.

>I could not progress any further it it, could
>not get a straight line of weld, the Welding
>rod would dance about too much.

This is exactly my experience but, with further practice, I hoped it might be tamed. I'll have to see!

>Good luck with your spot-weld project

I hope to have a 'test-firing' later today, so see if it works even at the most prototype, simple level to produce a spot weld without completely overloading the mains input at either 13A or even 30A.

>the wife would go mad with me blowing
>the fuses round the house all the time

If it does work without blowing fuses, I'll write it up on the project pages.

UPDATE 1: the prototype spot welder did work after a fashion. It shows potential. The good news is (a) that it didn't blow the 13A fuse or cause a bang when powered up and (b) it seems likely to take several seconds with my low-ish powered home made unit to join 2 pieces of steel of 0.7-0.8mm, compared to a fraction of a second with commercial units pushing out three times the power.

UPDATE 2: the prototype spot welder now works very well indeed. Further details and photos can be found here:

http://www.mig-welding.co.uk/forum/showthread.php?p=95197#post95197

Please post any further comments on the spot welder on that thread, rather than on this one.

 

[GeorgeB]

There's nothing like a deadline to provide some motivation. Just in case the meeting is arranged very soon, I thought I'd better resume practice immediately. For once, I worked outside in the dark, under lights.

I've put the Kel-Arc to one side and resumed practice with just about the simplest, lowest cost kit and rods available:

- buzz box arc welder
- Aldi 1.6mm 6013 rods

No copper, other backing or anything. I used a spare bit of space on the 0.7mm panel which I presented here a few days ago, and ran a 6.5" arc weld mid-sheet. This is certainly easier than a joint and it's how a lot of people demonstrate their MIGs, so it must be a reasonable thing to try.

The weld is a bit wobbly and I hope to refine my straight line technique later. The key thing for me is that I can now run the bead mid-sheet without blowing holes. Here's the top side, barely 1mm proud of the surface:

And here's the reverse side, which seems to represent fair penetration as far as I can tell:

It may be desirable to add more 'new metal'. Perhaps I could use a larger arc rod. If I can demonstrate this at the meeting with my buzz box, I'll be interested to see if any of the other machines can do much better. There's negligible, if any splatter, too. Marks either side of the bead are almost wholly from earlier practice runs.

 

[shenion]

Did you do it veritcal down? That is easier as the heat rises and you always are moving on to cool metal.

May try doing more 0.7mm this weekend. Did a pass easily in the middle, now need to try a butt weld.

I was using 7014's as they are a medium-low penetration rod.

Need to play with settings, was on the 5-60A range on DCEP.

Bigger (better) welders are supposed to be easier on thin metal as they have an higher OCV. DC also will have a more stable arc and you can adjust penetration with polarity.

Lincoln electric "Stick Electrode Welding Guide" has a section on welding sheet metal.

Edit: here's another try:

0.8mm steel.

Left is two tries mid-sheet, upper is 1.6mm MG500 (close to 6013), lower is cheap 2mm 6013 rods.

Right is tries with 1.6mm rod. Upper is DCEN, worked but the arc would "stick" to one edge. Bottom is on AC (white box). First blew holes as AC has higher penetration. Then it seemed to work better, I was probably down in the <20A range. Hard to say as Airco has no scale.

Funny, Lincoln recommends 2.4mm rods for 18GA steel. Would make sense as a bigger rod would bridge the gap easier.

Was real difficult as arc wanted to stay on one side. Even did so on AC. If you stopped moving and weaved to get arc to other side you blew through.

It was much easier with the 7014's.

 

[GeorgeB]

Did you do it veritcal down? That is easier as the heat rises and you always are moving on to cool metal..

Shenion - yes, it was vertical down. The photos were vertical at first but I rotated them on the web page to avoid too much white space.

I now realise there's a huge difference between welding mid-sheet and trying to weld a butt join. I'm still blowing holes on the butt join, so you're ahead with your DC welder. I must get my cheap DC inverter out again. When it wasn't brilliant a few months ago, I thought it fitted what my neighbour (retired welder) said about DC being no good on steel, so I put the DC inverter away. But then you and others have said on here that DC should be better, not worse, so I must give it another try.

Your photos are very interesting. Keep them coming. I must try the other rods which you recommended. I haven't tried anything apart from cheap 6013 rods, so far.

>upper is 1.6mm MG500 (close to 6013),
>lower is cheap 2mm 6013 rods

The difference between those two welds is amazing!

My current position is that I still need the Kel Arc to avoid blowing holes on a simple butt join, with a gap the width of a hacksaw blade.

 

[shenion]

Actually AC was a bit easier as far as bridgingthe gap, but had higher penetration.

6013 rods do not like running below their suggested current. It is real hard to prevent slag inclusions as the slag cools too fast.

The 7014's are much easier. I have a 1/2lb pack that I treat like gold as I don't want to waste them. 7014's are becoming much more popular here. I see many more on ebay and in stores. They are a fast fill rod like the 7018 but you don't need to keep them in an oven. Been looking for a bigger box as buying 1/2 lb at $5 is expensive.

You want no gap and a tight fit. Any gap and the rod will just arc to one side.

 

[GeorgeB]

You want no gap and a tight fit. Any gap and the rod will just arc to one side.

This makes sense and the no-gap approach was what I was going to try next, amongst some other ideas. I've read you should leave a gap to ensure good penetration, normally in the context of MIG welding. But it's over penetration, leading to holes, which are my problem with the arc on a thin sheet joint with a gap.

 

[shenion]

MIG has a lower penetration, so you need a gap on thicker stuff. You don't want a gap with MIG either, it will have the same problem of the arc being pulled to one side.

The gap would be normally less than 1/2 the thickness. At 0.8mm, that is almost no gap.

 

[fluxcored]

George, just for interest - is it possible to use a filler rod when you do the edges?

I sometimes do it when I do thin sheet with stick and find it acceptable. Do'nt really know whether it's advisable tho - I just do whatever it takes to get the job done.

Maybe the experts can chime in and give their opinion - real interesting thread. I must get myself some 7014.

 

[GeorgeB]

George, just for interest - is it possible to use a filler rod when you do the edges? I sometimes do it when I do thin sheet with stick and find it acceptable. Do'nt really know whether it's advisable tho - I just do whatever it takes to get the job done.

Good idea! I'll try that next. I agree 100% that it makes sense to do whatever it takes to get the job done.

We had the 'weld-off' meet arranged by Malcolm yesterday and it was most enjoyable. I'll let Malclom take the lead on the main write-up but suffice it to say it was a pleasure to meet Malcolm, Aero and Snowcat and I am so grateful to them for bringing along, or providing, so much equipment to try out. Here's a photo of Aero trying out one of my toy town, buzz-box arc welders - a Cosmo 150 (SIP I think) which I bought from B&Q. It's the yellow box on his bench.

Aero was making fair progress in laying down some half-decent beads with that arc welder before smoke starting pouring out if it and the overheat/cut-out switch was activated!

Back home, I was pleased to find that the arc welder was not too badly damaged and I was able to do a butt join of two strips of 0.8mm car body panel. I've found that butt joining without a gap works best. I've found that the prescence of any gap on such thin metal, simply increases the chance of blowing holes. Here's the front (the panel measures about 1.5 inches x 5 inches):

I did this by first laying down a 'root' of numerous tack welds, like small spots. I then did a 'cap' seam along the whole length. The others will confirm that I'm not very good at laying down a neat, smooth weld. They would be able to get a neater finish but, as it would be ground off on a car, I'm not really bothered. Here's the reverse side, showing fair penetration:

Conclusion: no need for a Kel-Arc welder attachment after all!

 

[aero]

I'm glad it survived! I was a bit worried about it.

It seems to have a dual protection system. Smoke pours out of it to alarm the operator into stopping, then if that fails it cuts off.

 

[Muggins the Mug]

Smoke pours out of it to alarm the operator into stopping

That's probably not a good sign.

Regards,

Ian.

 

[GeorgeB]

I should say sorry to SIP for making their Cosmo welder look bad, instead of the first class unit it is. I mean first class in terms of primary functionality. I've been very pleased with it. There are some minor shortcomings, however, including the lack of any fan (no 'turbo' cooling on this most basic of arc welders!) and I noticed some exposed wires inside the case. It might meet CE standards but I thought I could improve on that so I used self-amalgamating tape and some other materials to try and improve the 'build quality' of the wiring. The welder had then been used on low settings at home without incident. But my guess is that when Aero ramped it up to near maximum power output and welded away for a minute or two, it did of course, start to creep up in temperature as it neared the duty cycle limit for higher output. Then, my new materials reached their smoke point just before the cut-out switch was activated. That Cosmo welder would never have started smoking if I hadn't touched it! I'd used it on maximum power output before and it worked well, within it's duty cycle limits, of course. I can live with that as a DIYer.

 

[aero]

Aero ramped it up to near maximum power output.

ME? With my reputation?

I was quite enjoying myself with the cosmo, it wasn't doing a bad job. You could maybe add a cooling fan, they seem to be available. The arc wasn't as stable as the other machines and maybe a little harsh, but with a bit of deft of hand it was welding OK, until well erm....yes.

It was a very visual demonstration shall we say?


I was very impressed with the Wolf inverter though, if you just wanted to do light occasional welding in a workshop it welded really well, out of the two I'd use the Wolf as my main machine.

I will see if I can find some hi temp insulation used on aircraft engines if you want george?

 

[GeorgeB]

Aero - I should say sorry to you too, for perhaps giving you a bit of a fright when smoke started pouring out of my Cosmo welder! It wasn't your fault, of course. You were getting far better results out of it, than I ever have, in terms of smooth, consistent weld beads on medium thickness metal! I look forward to reading Malcolms write-up on the other welding machines, including my Wolf Inverter, your superb Portamig and Snowcat's amazing Lorch do-almost-anything-you-could-ever-need inverter (and your Oxford of course).

And, yes, I'd be most grateful for any tips on types of insulation which might avoid any risk of smoking at high-ish temperatures.

 

[aero]

Thats OK, I'm just happy it still works and it didn't get broken.

We forgot to get the Lorch to make the tea though....Im sure there was a program on it somewhere

 

[scarecrow]

Aero - I should say sorry to you too, for perhaps giving you a bit of a fright when smoke started pouring out of my Cosmo welder! It wasn't your fault, of course. You were getting far better results out of it, than I ever have, in terms of smooth, consistent weld beads on medium thickness metal! I look forward to reading Malcolms write-up on the other welding machines, including my Wolf Inverter, your superb Portamig and Snowcat's amazing Lorch do-almost-anything-you-could-ever-need inverter (and your Oxford of course).

And, yes, I'd be most grateful for any tips on types of insulation which might avoid any risk of smoking at high-ish temperatures.

well Aero spill the beens did George blow a fuse when he saw smoke coming out of his welder or did smoke start coming out of his ears as well

 

[malcolm]

Have to say I'm impressed with your results on the 0.8mm. It would be fun to compare processes.

We did a little test like this in our weld off. Snowy tried a butt weld in 0.8mm with the cheap 1.6mm rods using his fancy welder, and, while his results were much better than I'd managed with my arc at home, he still blew big holes every quarter of an inch.

I think I showed him up when I laid a lovely bead with the MIG that aero had lying around. Had to use the stop start method as we were running 0.8mm wire, but no holes and a good strong weld.

Have you compared your gasless MIG against the arc welder yet on the thin stuff?

 

[GeorgeB]

Have to say I'm impressed with your results on the 0.8mm. It would be fun to compare processes.

Thank you for your kind comments even if it is a rather eccentric exercise. The welds above were done with the Cosmo (AC of course). You all raised my interest in the DC-based Wolf Inverter on Sunday, so I must now try welding 0.8mm sheet with that inverter. Prior to Sunday, it had been in the loft, untouched for about a year!

I was hesitant about mentioning Sunday's 0.8mm test (or it may have been a tad thicker - I must check) here but as you've now referred to it, I know the Lorch could have done a first class job, if anyone had used the 'root tacking' process which I now use. Nervertheless, the Potamig was nothing less than a revelation and I'll say more about the MIG on the thread entitled "arc vs mig". I have the original metal work but I don't think it would be fair to post photos of our failed attempts here (unless you think I should).

I don't have a gasless MIG; only a normal MIG but I've not yet fired it up. I'm keen to try it on both gas and gasless. I assume I can 'convert' it to gasless simply by reversing the polarity of the main outputs.

 

[irondarren]

George yes reverse the polarity for gas less wire, and it should work fine. Most gas/gasless machines have an easy method of polarity change normally by putting the earth terminal in the + and cable that comes out of the machine in the - terminal, and you should be good to go