Thread: Are Uni Mig Stick Inverter Welders any Good?

The comment Karl made about current input is spot on.
especially,say,if you live in an area where you are the end of the supply line.
Its more the gys with big air con units and pool pumps that are sucking up the juice before it gets to you.

My multi meter clocked 240 volts at off peak and 214 volts (not a typo) at peak.

Add bad earths and cable faults and I could see a problem happening. Check that out, perhaps before taking it back.
cheers
Grahame

Originally Posted by Grahame Collins

My multi meter clocked 240 volts at off peak and 214 volts (not a typo) at peak.

The official Australian mains voltage is 230V +10%/-6%, meaning it can range from 253V down to 216V and still be within spec.

The nice thing about inverters is that they can happily cope with a huge range of input volts while still delivering the set current. That said, if there is seriously dodgy wiring such as a hot joint somewhere, it's certainly possible this could affect the performance of the machine.

While we are on this topic I found unimig 170 for sale. The asking price is about 120 below normal retail and the welder appears to be in good condition. I think that CC supply a 3 month warranty but check to confirm this. If you are in the area you could drop in and maybe haggle a bit for a better price. Morphett Vale, SA, 5162

Here is the link..... https://webshop.cashconverters.com.a...-unimig-arc170

As an update to this thread, (I haven't welded for weeks have been unwell) I had someone weld with my welder he found no major problems. However he did not like the electrode holder it doesn't seem to keep the electrode tight and seems to come loose.

Also I have a few technique issues to work on mostly arc length.
He also mentioned earthing issues through my work bench.

So I am going to buy a new electrode holder and practice my stick welding more.

Thanks for all the replies.

Originally Posted by BigPete1

So I am going to buy a new electrode holder and practice my stick welding more.

Thanks for all the replies.

Go and learn from a good teacher at TAFE, I doubt that anyone can learn by themselves to be a good stick welder. I know that everyone will come out and tell me that this is not so but I don't believe that anyone who is not taught what to look for, how to assess and test and lastly how to change their technique to overcome problems can ever do much better than glue two bits of metal together with a stick welder. It simply comes down to two choices, do you want to have confidence in your welding or do you want to fumble along and hope it holds together?

I dunno, unlike MIG where you can make a weld with good appearance that has poor penetration and poor overall strength, with stick, if the weld looks good, chances are it is good. That said, achieving that good-looking weld is the challenge with stick, particularly once you start doing fillets and non-horizontal welds.

As for holders, when I got my little BOC inverter it came with a jaw-type electrode holder, and I considered replacing it with a twist-handle type, but once I used it, I found it was fine. My UniMIG has the twist-handle type and it's also fine, but some people are probably a bit pickier than me (and probably better welders ).

Originally Posted by RustyArc

I dunno, unlike MIG where you can make a weld with good appearance that has poor penetration and poor overall strength, with stick, if the weld looks good, chances are it is good. ).

As someone who was formally taught I can't agree. How many things can go wrong with a stick weld...

Poor peno
undercut
inclusions
poor leg length
poor reinforcement

caused by

wrong heat setting
wrong rod - size and type
wrong angle - both ways
poor prep
poor weld technique - that is how to lay the weld in the correct way - vertical up is a good example of this as is a multi run fillet weld. The run sequence and weld angle is critical to laying down a weld that has equal leg length and good reinforcement.

I suppose the come back to this is "I am only welding at home for me and it does not matter if I get some stuff not quite right". People have been killed with that attitude, an amateur who does a job he should not have touched because he thought he was a competent welder but had never sought to find out if he was competent or not. My teacher was a DLI (at the time) inspector and used to assess accidents caused by poor welding and his stories illustrated just this point in many cases. Even competent welders get it wrong.

A bit of fatal trivia and I hope my memory is good but the outline is if the detail isn't. Two welders were finishing a BIG pressure vessel and were leak testing it in Wagga many years ago with fatal results. To short cut the job they decided after a while instead of dropping the air each time a leak was found and needed repair they would weld it under pressure. They were working on the top of the vessel and as soon as the welding started the vessel burst and killed at least one of them. Even experts get it wrong.

Originally Posted by Chris Parks

As someone who was formally taught I can't agree. How many things can go wrong with a stick weld...

I'm not going to argue that formal training isn't a good idea - the first thing I did when starting welding was a course at the local TAFE. Probably the most informative thing was putting welded pieces under the press and observing how (and when) they failed - seeing how a weld fails tells you heaps about what's important & why. I still learn from having welds fail, but only in non-critical applications, like making a compacting plate for my demolition hammer (which still hasn't survived more than about 5 minutes, making me realise why the commercial ones are a cast piece).

However, when it comes to the self-taught welder, I'd still say that someone teaching themselves with stick, assuming they give a rat's about weld appearance, is going to do more structurally-sound welds with stick than MIG. A weld with inclusions or undercut will look like crap, as will an uphill vertical done poorly. The danger with MIG is that with a bit of weaving etc. you can lay down a nice-looking weld that's barely penetrated the parent metal.

[QUOTE=Chris Parks;1586765]Go and learn from a good teacher at TAFE, I doubt that anyone can learn by themselves to be a good stick welder.

I don't disagree with you Chris, but have you got any idea how difficult it is getting into TAFE when you live in a rural area.
I waited 2 years to get into a 6 week welding course, which is just not long enough to learn it all. Courses at my local TAFE have been cut to the bone and the remaining courses only cater to industry, not home hobbyist / farmer welder like me. As I'm not in industry I'm not a priority for Tafe in their already limited places. Also I didn't seem to have as many problems welding at tafe compared to home. The teacher was good but fighting for his attention amongst 11 other guys is not always easy.

Hi Bloke

My inverter is not the same as yours, but i too found problems with the rod sticking. Have come from a CIG Transarc 140 to the new inverter. Old transformer was great to use, scratch rod on floor, insert, weld. New Inverter, rods stick, much cussing, then I read in here about heating the rods, tried that, rods arc almost every time on first strike now. Almost, as I have some 10 metres to walk to shed from oven. I be buying myself a rod warmer for Xmas.

DD

I do have some idea and yes I am guilty of assumption on that issue. The TAFE system has been systematically raped and pillaged over the years and we have allowed it to happen. It took me five years of night courses, six weeks is not going to do much at all. Maybe get some local interested people together and approach a welding teacher on a private basis, is this practical? or talk to a teacher and see what is possible.

A good way to heat rods is make a tube with an incadescent light bulb in the bottom of it. Put rods in, turn on globe and rods warm up. Pressure welders used to do this to keep inclusions out of re-starts and it works well on rods that have been laying around a long time and absorbed moisture. Finding the globe might be an issue these days.

Originally Posted by Chris Parks

A good way to heat rods is make a tube with an incadescent light bulb in the bottom of it. Put rods in, turn on globe and rods warm up. Pressure welders used to do this to keep inclusions out of re-starts and it works well on rods that have been laying around a long time and absorbed moisture. Finding the globe might be an issue these days.

Heard another good tip for this one. Say you wanted to use a 100w bulb. Instead of that one bulb straight across the mains, use two 100w bulbs (space to fit them in has not been factored in here though LOL) and wire them in series. Each one will have half the voltage across it so they're a 50w bulb each but totalling the same 100w. The benefit to this is the bulbs, when burning with half the voltage, don't blow so easilly. I know I've been through lots of bulbs in hand lamps when they get a bit of a knock while they are on. The guy who suggested this tip said the bulbs last forever when wired in series.

This is a great thread
All the way from cheep chinese welders to wiring light bulbs in in series to make them last for ever (and stuff in between)
Well done
Take a bow guys