A bit like welding with a woodpecker!

I've been doing a welding course at a local college for a few weeks now and today I finally got to try doing some at home with a welder I'd bought. Unfortunately it's a Cosmo / Sip and since discovering this forum I've become familiar with their wire feed problems. I've done a couple of the modifications suggested on here; changed the torch liner from plastic to a metal one and I've put a bracket across the wire feed rollers to hold them in place, but the power supply modification is a bit beyond me at the moment.

On the whole it went much better than I'd expected and I'll take some photos to post tomorrow in the hope that I'll receive some feedback that'll help me improve. Just a couple of questions for now though:

1. Whilst I was welding I could hear the wire feed speeding-up and slowing down without any input from me, but it didn't seem too bad. Sometimes though, the end of the wire was jumping around (pulsing?) and almost hammering against the steel, which reminded me of a woodpecker hammering at a tree! It was a bit of a nuisance (to put it mildly!). It seemed to be happening regardless of the wire speed doing it's own thing? Also, sometimes the end of the wire was briefly sticking to the steel as well. What's this all about and what can I do to try and stop it happening?

2. Some of the welds are tall and rounded, rather than flat and wider. I've just had another look at the tutorials on here, so it sounds like I've been moving the torch too fast and need more side-to-side movement?

Very grateful for any advice, which might not be easy to give until I post some photos. I was working with 3mm steel, argon/co2 gas mix and 0.8 wire.

Tony

Too tall maybe too low a power setting. The wire thing could mean the rollers need cleaning or that somehow (it's easy done) you're using the 0.6 grooves rather than the 0.8. You need to set the tension so that you can slow down, or even stop the wire feed between finger and thumb at the end of the torch.

Get the wire feed sorted first, as that'll make everything else clearer -- it really does create a lot of problems. Also, check the earth. If it's getting too hot or not making good enough contact that will create a lot of issues.

I use an SIP regularly, but have never put .8 through it, what works for me is the wire feed set at about 9 oclock and on the power switches, cant remember how they go now but one down from max on 3mm stuff, otherwise I find the .6 wire melts back into the tip, try getting that out!!!
Probably better with .8, but I use my mma set for 3mm plus work.
the chattering could be an earth problem as suggested or even muck on the bit your trying to weld, or mine will play up with not enough gas flow.
as fingers said the wire feed is key to getting a good weld, if its not right and smooth you can spend all day trying and it will look like pigeon poo!!

Paul..

Sounds to me like you may have your wire speed a littlle high this would also account for your tall welds , back the speed off a small amount at a time , power and wire speed settings are pretty critical to get that nice buzzzz and a good weld

paulmowers said:

I use an SIP regularly, but have never put .8 through it, what works for me is the wire feed set at about 9 oclock and on the power switches, cant remember how they go now but one down from max on 3mm stuff . . .

Click to expand...

Phew! I'm relieved to see that I've been using the same settings that somebody else uses for 3mm.

Thanks guys for all the suggestions. That gives me a few things to have a look at when I do a bit more practice today (weather permitting).

Tony

Here's a pic from yesterday:



In this one, the three rows on the right are from yesterday and the three on the left are from today (having slowed the wire speed slightly and introduced some side-to-side movement with the torch):



Also from today's practice:





I didn't have any problems with the wire stuttering / hammering against the steel today and I'm wondering if it might've been happening because I forgot to clean some patches of light rust off the surface of the steel yesterday?

Tony

Could be. What's the penetration like on those? But at least that's a big step forward.

I would cut through that fillet weld and have a look at the root, Its not always easy to tell from a photo but that looks a bit cold to me. nice steady hand though