Sip140 and new to welding

[rich r]

Have a read of the tutorials at the top of the page, and watch some of the videos on YouTube (see if you can find the excellent British Welding Institute ones) - it's all about practice, practice, practice. Eventually you'll get the hang of it, and controlling the arc speed and distance will come far more naturally. If you learn on an ac buzzbox, you'll develop the right techniques rather than letting fancy electronics compensate.

Stick with 2.5mm rods - in my opinion they're the best size to learn with (smaller is more difficult, bigger allows you to be a bit sloppy and get away with it). But see if you can get hold of some steel about 4mm thick. Welding 2mm thick steel with an arc welder takes a fair bit of skill, quite low current, and small rods.

Keep at it, keep posting photos and you'll get there

 

[Kent]

forget what any dial says on these things, just plain fiddle till its striking up right and running like you want. 2,5mm rods are just the thing it aint got the guys or duty for bigger I bet and smaller are pretty much a niche thing.
I am never too sure when people talk of the skill level, stick welding on the flat aint too hard to teach someone to a "passable" amount of proficiency. The issue generally is in the set up and such when you maybe don't have the understanding of the factors

 

[PTvor]

Guys I have been really enjoying practice over the weekend but got to welding some ~ 2mm thick box section today and I blew a hole straight through!! I actually couldn't believe it. I'm using the 2.5mm rods, but do I need to reduce the current or different rods??

Arc really comes into its own with metal 3mm or thicker. You can weld thinner steel, but it gets much harder as you get to 1.5mm thickness. I'm not at all surprised that you've blown holes in 2mm steel. On the contrary, I'd be surprised if you hadn't. You're trying to practice at an early stage on something tricky even for people with a lot of experience. This is like trying to swim a river when what you should be doing is to make sure you can swim a length of a swimming bath comfortably.

You need to get some scrap 3mm or thicker, the thicker the better really. A piece of 6mm plate or an offcut of I beam would be ideal. Clean it back to bright with an angle grinder particularly making sure that the spot where you put the earth clamp is clean. Good, dry, branded rods are also well worth having as they are easier to use and more consistent than cheap ones. That welder should be able to burn 3.2mm rods, but you're more likely to blow fuses and have the thermal trip go, so you then have to wait ten minutes for it to cool down and reset itself. As others have said, stick to the 2.5mm for now. The first thing is to learn to start the arc and be able to lay down nice even beads on the flat. This may take a few practice sessions and a fair few rods before you get the hang of it and can do it easily.

There are lots of threads on here about people starting arc welding which are well worth looking through, as well as the tutorials and also some good videos on YouTube.

I don't know if it's been mentioned earlier in the thread, but if you are using a hand held mask, that's an added obstacle. You'll find it much easier with an autodark helmet. You can see what you are doing before you strike the arc and you have two hands to hold the tongs.

 

[Kent]

Some are making it sound harder than it is don't be put off

 

[Chrs]

I'm getting there guys. Brought the current down and run a much nicer bead on flat. I also had a go on the 2mm cut box and didn't blow a hole in it this time.

Constructive criticism on my welds are more than welcome.

 

[rich r]

Not bad at all. Current maybe a little too high (see how it's undercutting at the edges of the bead?) also if you turn it down a bit, you'll be able to go a little slower if you want to which might help maintain a straighter line. But otherwise if you've only just started doing this you're doing great!

 

[Chrs]

Hi, thanks for that. Yes, just started, burnt through about 5 rods in total.

I don't know what you mean by undercutting, can you explain?

 

[Bill Edwards]

Undercut is where the metal right next to the weld is thinner - i.e. it has been 'cut' out. This means the metal is then weaker as it isn't as thick.

Your welding is looking very good, well done.

 

[PTvor]

Hi, thanks for that. Yes, just started, burnt through about 5 rods in total.

I don't know what you mean by undercutting, can you explain?

http://www.esabna.com/euweb/mig_handbook/592mig10_5.htm

Caused by excessive current, wrong travel speed or wrong rod angle. It's a weld defect and a source of weakness.

It's looking good, but I still think you'd make better progress learning to put down beads on a thick plate consistently, using the whole rod, before attempting joints or trying 2mm steel.

 

[rich r]

Agreed - see if you can get a bit of 4mm or thicker steel plate - even a lump 5cm x 5cm would do, but ideally at least 10cm runs are better as you get a decent period of time running the bead before you have to stop - meaning you can settle into moving at a smooth consistent rate. Run a bead from about 5mm in from one corner parallel to the edge, stopping 5mm before the other edge. That way you can follow the edge to help you keep a straight line. Then run another bead next to that one and so on until you've used up a rod or run out of plate. Knock off the slag and have a look at each run - you should see that as you go along you're hopefully getting the speed, arc length and angle more consistent leading to nicer looking welds. Then grind it all back (or a coarse flap disc) and repeat.

 

[GeorgeB]

Firstly, people on here talk about setting the current but this isn't displayed on my machine. There is simply a min and max rotator to set the current. It doesn't even have end stops and spins in both directions continiuosly so I'm not even sure what is max and what is min. Is there any setup I can hook up to measure the current and display it?

Chrs - thank you for reminding me that I have a SIP 140 arc welder and it's been neglected for too long in conditions which must have been far too damp. My SIP 140 was never as rusty when I last used it, about a year ago. I rate this unit very highly for jobs where I require a bit of power. The minimum current specified is 30 amps, which is the same as another buzz box of mine - a Cosmo arc welder. But I wouldn't attempt to weld anything much below 3mm with the SIP 140, whereas I happily weld steel plate down to about 0.8mm with the Cosmo. All buzz boxes are not the same.

Here are some images which may help you:

1. A side view of the workings. I recommend taking the cover off to look inside - an easy task. The shunt, which I've bracked with red lines, is fully out towards the front of the welder. This is the full power position, and the adjustment knob should reach an end point. If yours turns endlessly, then I suggest looking inside to understand what's going on.


'

m


2. Inside view of red indicator arrow (a neat idea) which should be seen through the plastic window.

3. A view of the plastic window with the arrow pointing to 115 watts (approx).

4. A close up of the current markings - upside down to maintain the same orientation, throughout my images.

I hope this helps.

 

[brightspark]

wb george

 

[skotl]

wb george

I just did a search for "pre-moderated" - it doesn't mean what I assumed it meant...

 

[the snooper]

Chrs - thank you for reminding me that I have a SIP 140 arc welder and it's been neglected for too long in conditions which must have been far too damp. My SIP 140 was never as rusty when I last used it, about a year ago. I rate this unit very highly for jobs where I require a bit of power. The minimum current specified is 30 amps, which is the same as another buzz box of mine - a Cosmo arc welder. But I wouldn't attempt to weld anything much below 3mm with the SIP 140, whereas I happily weld steel plate down to about 0.8mm with the Cosmo. All buzz boxes are not the same.

Here are some images which may help you:

1. A side view of the workings. I recommend taking the cover off to look inside - an easy task. The shunt, which I've bracked with red lines, is fully out towards the front of the welder. This is the full power position, and the adjustment knob should reach an end point. If yours turns endlessly, then I suggest looking inside to understand what's going on.


'View attachment 64315 m


2. Inside view of red indicator arrow (a neat idea) which should be seen through the plastic window.

View attachment 64316


3. A view of the plastic window with the arrow pointing to 115 watts (approx).


View attachment 64317

4. A close up of the current markings - upside down to maintain the same orientation, throughout my images.

View attachment 64318

I hope this helps.

ey up George hows the push bike going ? did it last the test of time ?

 

[brightspark]

I just did a search for "pre-moderated" - it doesn't mean what I assumed it meant...

it means mods look the post over before u can reply i got [put in the norty corner once and had to grovel to get it removed

 

[Wozzaaah]

Play nice please chaps, there's plenty of other naughty corners, there's also lots of new forum toys and a new sheriff in town.
Welcome back George.

 

[the snooper]

Play nice please chaps, there's plenty of other naughty corners, there's also lots of new forum toys and a new sheriff in town.
Welcome back George.

I dont see any unrest at all did I miss something ?

 

[PTvor]

Welcome back George.

I've missed your extreme cost aware view of welding.

 

[Wozzaaah]

I dont see any unrest at all did I miss something ?

Pre-emptive strike.

 

[GeorgeB]

Just to mention that, rather than risk taking this thread any more off-track, I started a new thread with some replies and other comments, for anyone who wants to discuss cost-conscious welding:

http://www.mig-welding.co.uk/forum/threads/georgeb-replies.54459/#post-642346