Completely new to welding - can't a good arc going

[JimBowen]

Hi,

Sorry for yet another "what am I doing wrong" thread, but I'm really stumped.
I bought a clarke 90en off ebay a while back, but have only just been able to try it out properly (i.e. on a clean piece of 1mm sheet, not just bits of random scrap)

When I try to weld, all I get is pop-pop-pop and lots of spatter everywhere, and it just makes a complete mess of the workpiece.
I've set the regulator to 10lpm, but tried it on 20 just in case.
I've made sure that I have a good earth, by clamping some thick wire to the piece as well as the cheapo clamp that comes with the 90en.

I don't know if it's the tip that's knackered, the wire feed, liner, or if maybe my mains wiring isn't up to the job.
The wire feed does seem temperamental. Sometimes it's pushing the torch away from the metal (obviously too fast), and if I turn it down only slightly it leaves a trail of tiny globs on the surface and sounds like a machinegun (too slow?) It also sounds like it cuts out when the arc strikes, but that might just be because the arc is so loud. It's perfectly smooth when i'm not welding though.

I did manage to get it to arc up properly once, but I could only do it on a high wire speed and maximum power, hence the hole in the metal. <_<

Anyway enough of my rambling, here are some pics of the horrific mess I made

 

[campervan]

i think an expert will be along later are you using gasless wire or is it normal
what bottled gas are you using and can you hear it when you press the trigger witout the power on
it does look at bit rough i must say i have a clark 110 and hav wire about 4-5 and my gas big bottle about 15-20 ? amps at 2nd setting try doing spots and see what happens have a look at other post of pic of welds to see what theres are like mine were rubbish till i got so gas but i could still get it to stick
has the motor got enough power to turn that roll of wire is it a big one i steered clear of buying one yesterday just encase the motor couldn't turn it man at shop wasn't to sure so i got two small ones

 

[cookie munsta]

mate i've no idea abot mains power, but by the looks of that your wire speed too high, umm what size wire are you using, if you using thicker wire than machine can burn that is what you will tend to get,

 

[JimBowen]

I'm using normal wire (mild steel, copper coated I think), 0.8mm with pure CO2. The gas is definitely coming out fine.
You might be right about the motor.. I'm certain that this is either a wire feed problem or a tip problem. The tip does look pretty knackered, it's a bit blackened and pitted, but I haven't been able to find a suitable replacement. The standard ones in screwfix, B&Q etc seem to be twice as long and with a bigger thread. Does anyone know which tips the 90en takes and where to find them?


As for the wire size, the machine can definately "burn" it, certainly on the higher settings, hence the hole in my metal.. But perhaps doing 1mm sheet with 0.8mm wire is just hard anyway?
I have some box section which is a bit thicker (and what I really want to weld eventually) so I'll try welding two bits of that together. The settings that blew a hole in my 1mm sheet seemed to otherwise work, so perhaps that will be more suitable on the box section.

Otherwise I'll see if I can pick up some 0.6mm wire (and tip) when I find a place to buy replacement tips.

Cheers

 

[malcolm]

Well worth having a new tip - they are only 50p each. Weldequip is yer man - send him a private message via the forum. They are standard 'hobby' tips.

My guess is you have the torch far too far from the metal. Have the shroud maybe 0.5mm or less from the steel. Doesn't matter if you bump it every now and again. Also make sure the shroud is nearly end on to the metal. 20 degrees out is as much as you want to be for thin stuff.

Assuming I'm right you'll be able to enjoy a reasonably big sweet spot between too fast and too slow, and adjust within that depending on what you are doing.

Tutorials might be worth a quick read through - think other issues should be captured in there.

 

[shenion]

I assume you meant 0.5cm or 5mm.

Yes, does look like long torch length.

 

[JimBowen]

Cheers guys, I'll try holding the torch a bit closer tomorrow morning and see how it turns out. If not, I'll get some new tips.
I take it 0.8mm wire is perfectly fine then for 1mm sheet?

 

[shenion]

0.8mm will work fine. 0.6mm will be easier.

If a closer torch does not help and you have good gas flow. then ther emy be a bad connection in the welder or a blown diode.

 

[sport.pilot]

Jim,
I tried learning on sheet metal, I think it was 22 guage or so. Way to hard to learn on. I then switched and practiced on thicker plate - 3/16, and found it easier to get the hang of welding a decent bead. I also started cleaning the metal really good and that helped me as well. Here are two links to a welding class that might be of use to you: http://www.youtube.com/watch?v=lzBGZaS1apw and http://www.youtube.com/watch?v=sMdQT-eswYY&feature=channel. The first one is basic MIG welding and the second is advanced MIG welding. They are videos of a college course. Good luck.
Darryl

 

[R Kraft]

I don't see a gas bottle in your photos.
If you are using a disposable bottle they are noted for not putting out enough gas.
Robert

 

[JimBowen]

Thanks guys, this site is amazing


I decided yesterday that it must be the tip, when I took a multimeter to it and managed to measure half an Ohm between the tip and the wire. I think this is bad... <_<
So I got myself some new tips, and also some 0.6mm wire and tips.

The 0.6mm is a lot easier to use, probably more suited to such a low power welder.

Thanks for the point about the sheet metal sport pilot. The box section is a lot easier to work with, and I managed to lay down a nice-looking weld (see pics below..) It started off a bit dodgy, hence the messy bit at one end, but I soon got the hang of it.
The reason I tried sheet first is because I had imagined my practice piece looking like the ones in the tutorials... :P

I wasn't convinced that my first attempt at welding two bits of metal together could have been successful though, so I tried testing it to destruction (and I failed!) first by bashing a chisel into the opposite side of the two pieces, which didn't work, so I got the sledgehammer out and pummeled the thing for all it was worth, first bending it one way, then the other, then back the first way again. Even though it was only welded on one side, the metal seems to have failed before the weld..

Not bad I think, considering my entire knowledge of welding has come from one website..

By the way Mr. Kraft, I do have a gas bottle, it's a pub-type cylinder of (pure) CO2, which came with the welder when I bought it off ebay. The pressure gauge reads approximately 850psi, which I believe is near the vapour pressure of CO2, so there should be plenty left.

 

[Coo]

at the destruction testing !

One thing I think I notice, remember to clean the surfaces that your going to weld, cant see how clean the box section is....

 

[JimBowen]

Ah yes, thanks for that.
I had assumed that I'd only need to clean it if it was rusty..
I think I'll get one of those flap discs like the tutorial recommends.

By the way, on an almost unrelated note, does anyone know the best way to cut box section? Or is just a plain old hacksaw the best way?
I did try using an angle grinder and a cut-off wheel, but it seems to take longer than the hacksaw and produce an ugly cut, let alone be frighteningly dangerous..

I'm actually trying to make what is essentially a radio controlled buggy. (except it's not really radio controlled, it'll actually be autonomous, or at least semi-autonomous)
I'm a programmer, really, hence my limited knowledge of welding :P
Anyone else here tried the same?

 

[Blurk99]

i've just ordered on of these - i'll let you know how i get on, sometimes these bits of kit can be suprisingly cheap, but that usually isn't the case with axminster....

jim

http://www.axminster.co.uk/product-Axminster-Angle-Grinder-Stands-20849.htm

 

[BillJ]

Before I bought a bandsaw (from Axminster), I used a hacksaw for everything. Slow (and tiring) but as accurate as you'll get. Abrasive cutters are fairly imprecise. A power hacksaw or a bandsaw is the only accurate alternative in my limited experience and even then a bandsaw can require careful setting up to get a straight cut.

I'm a programmer too (and very much a welding amateur) but I haven't tried building an autonomous vehicle.

And as you already know from the tutorials, get the metal shiny-clean!

P.S. that weld is looking a million times better than before.

 

[Angusdog]

I had on of those kits to convert an angle grinder to a drop saw, but they're limited in two ways. One is capacity - they can't handle anything larger than about 20mm square tube, and secondly you'll go through disks really quickly (and need the angle grinder to dress welds etc.

I got a chinese ("Euro"-branded ha ha...) abrasive drop saw, cost about as much as a reasonable angle grinder but it handles cuts with ease. I've got quite accurate with it now, and still on the first disk. That's after making various counters, furniture, a rotisserie for my mini with 88mm diametre x 3mm wall thickness tube, 50x50 x 5mm angle iron. Well worth a look as you can work a lot faster. You wouldn't think that someone pottering around in their home workshop would be considered with speed, but with family, dogs and work making demands on my time, plus trying to get a run in every now and then, time is remarkably precious to me. My wife is amazed that with an hour or two and a shedload of noise results in a useful trolley or a material rack - and that's in my garage which is only just big enough for a mini

Failing that, there seem to be a lot of bandsaws at various price points which may fit the bill. Don't underestimate the value of some of these tools - you want to be making stuff, not faffing about with a hacksaw! I've never been able to cut a perfect 90 degree cut anyway.

 

[cookie munsta]

mate a drop saw is the go, if using to mitre let the disc cut through as opposed to push it down too hard as you will notice some flex which will throw it of slightly. otherwise really good great on site.as for destructive testing i'm not sure about lighter stuff but i usually take most of the reinforcement face off, and then bend weld back on itself, i'm usually looking for peno of both parent metals and minimal inclusion but enough with my obsessions, as for the tip, the knee bone is connected to the umm the,the whatever, but it may be the case with the tip as the tip goes into the gas diffuser, so maybe if change the brand of gas differ you might get another range of tips, or not?

 

[JimBowen]

mate a drop saw is the go, if using to mitre let the disc cut through as opposed to push it down too hard as you will notice some flex which will throw it of slightly. otherwise really good great on site.

Cheers. Sounds like a drop saw is the way to go then, as long as it's cheap..
I'm only in a small garage like Angus, but a hacksaw just seems a bit primitive :P
besides, I can never seem to get the thing to cut straight.

By the way, has anyone had any experience with so-called "plasma cutting discs"?
Are they just a con for people who don't know what a plasma cutter is, or are they any good?
(I can't see how "plasma" can be involved in a cutting disc, other than for marketing perhaps)

as for destructive testing i'm not sure about lighter stuff but i usually take most of the reinforcement face off, and then bend weld back on itself, i'm usually looking for peno of both parent metals and minimal inclusion

Well I did try bending the weld back on itself, but after snapping off the chisel tip between the two bits of box section and having to re-sharpen it, I gave up.
Might have been possible had I ground off the top of the weld, I don't know..
What do you mean by "inclusion" by the way?

as for the tip, the knee bone is connected to the umm the,the whatever, but it may be the case with the tip as the tip goes into the gas diffuser, so maybe if change the brand of gas differ you might get another range of tips, or not?

Unfortunately with this welder, the gas diffuser is part of the swan neck (it's the same piece of brass as far as I can tell) and the swan neck doesn't detatch from the torch either, at least not without dismantling the torch. It's also not a standard one either as I believe those have screw threads on the end?



One more thing in my little multi-topic noob thread:
How the heck do you weld in a straight line?!
That piece at the top of the page was pure luck. My subsequent attempts have gone way off course and left me cursing as I'd completely missed the join and had to go back over it, probably producing an extremely weak weld..
I find it hard enough to draw a straight line with a pen and paper, let alone with the end of a welding torch, blind, and whilst trying to move slightly from side to side as I go!
How fast do auto-darkening helmets return to visible after the arc stops? Is it quick enough to see where you're going before the weld pool solidifies?

 

[Sparkey]

You could try drawing a chalkline on the part you need to weld, you should see it more clearly through your mask...
Once you get more experience you will learn how to "see" what you are welding! And offcourse your hand will become steadier!
And you don't have to weave at first, just try going into a straight line first!
hope this helps a bit!

 

[Angusdog]

\How fast do auto-darkening helmets return to visible after the arc stops? Is it quick enough to see where you're going before the weld pool solidifies?

Auto darkening helmets are the mutt's nuts. Get one with adjustable sensitivity, delay and shade and your welding will magically improve out of sight. You can adjust it to see the weld pool and the metal, and everything becomes much easier. Best value improvement you can find.