Author Topic: MIG Welder, what to look for?  (Read 956 times)

glort

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Re: MIG Welder, what to look for?
« Reply #15 on: May 12, 2019, 05:22:51 AM »
One of the biggest problems with all welding equipment is the rental contract on the gas bottles, oxygen, acetylene and argon.

I have a couple of good oxy sets up the back I doubt I'll ever use again.  Bottles can be purchased now and refilled a lot cheaper than the BOC extortion prices but still not that cheap and still a pain in the arse really.
I have a plasma cutter and the Mig will weld anything I want.  I also have an LPG set but haven't had much occasion to use it.  Still needs the Oxygen  from a specialist supplier rather than teh local servo for the gas.

I did make up my own torch some years ago that ran on compressed air and LPG. It worked but was more of a brute force thing to get to brazing temps for yellow tip than outright heat. I was kinda wondering about  TIG because to me that's like electric gas welding... much as that analogy will no doubt send the purists into another hissy fit.


Quote
In an effort to avoid these costs I have experimented with gasless mig where the welding wire contains a flux. Takes a bit of getting used to but gives good results and you are never going to run out of gas again.

I have used the gasless  fluxed MIG wire for years and never had a problem with it.  Never had a weld break but i have had a bit of metal tear on the non welded sections. in any case I'm not welding boilers or critical stressed components Holding Bridges together so no use going overkill. The gasless MIG system has never been the problem, just the machinery to apply it is now worn out.

I will probably stick to the gasless MIG as it's never left me wanting for anything more unlike the machine.
Had a look at some today and they are hard to dicern one from another. I did see one Little 100A Inverter machine. I thought it was a stick at first but it was actually a MIG. I think it was gasless only but it was tiny.

There are a stack of welding places around here as i discovered when looking for tips for the plasma..... None of which any of them  had but I found on the net for a fraction of the price and had them here in 2 days. So many differnt brands and Models within each brand. I suspect some of them are exactly the same with a different colour paint and control layout.

The Plasma is a UniMig which is Italian. The distributor is not far from me and last time I rang them with a problem with the plasma, the guy could not have been more helpful. Treated me like a dear mate rather than a customer. Fixed the problem while I waited and wouldn't take any money. Said it as a machine fault even though the machine is about 10 yo and called it warranty.  the things are at the upper end of the price scale but service like that goes a long way.

Still hard to work out what a decent machine is and one that's no better and probably price inflated.  Pretty sure the  CIG/ BOC one I looked at was made in china as well. 

glort

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Re: MIG Welder, what to look for?
« Reply #16 on: May 12, 2019, 05:33:59 AM »
Yeah, I have LPG/oxy in the cutting plant at work - heaps cheaper


Last time I used mine I wasn't that sure of the economy although it was a while back before the price of the bottled gas went nuts.
The LPG was noticeably weaker in cutting although I didn't find much difference with brazing/ welding  and because the oxy rate is twice as fast as with acetylene, you go thought that a lot faster.

The fuel gas is cheap but I got the impression you made up for it with the oxidiser.

In any case, Since I got the plasma I haven't had need or want for the gas axe.  I have cut copper and aluminium with the Plasma and the Only thing I found it Did not like was a Rusty car Body a friend wanted Chopped. I got around that by using a clean steel guide Piece I grounded to the earth cable and ran the head along that. Sustained the arc and worked OK.

I do see there are Hydrogen/ oxygen torches now that break the water down to produce a very hot gas.
I have seen them on chinese websites and Fleabay But i can't find any from mainstream manufacturers so i'm not sure how trustworthy they are or if they meet reasonable safety standards of the west.

Some I saw seemed to deliver the gas in one tube which seems very iffy and the others had the gases separated to the torch  which would seem logical.

mike90045

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Re: MIG Welder, what to look for?
« Reply #17 on: May 12, 2019, 06:21:26 AM »
.....
I do see there are Hydrogen/ oxygen torches now that break the water down to produce a very hot gas.
I have seen them on chinese websites and Fleabay But i can't find any from mainstream manufacturers so i'm not sure how trustworthy they are or if they meet reasonable safety standards of the west.

Some I saw seemed to deliver the gas in one tube which seems very iffy and the others had the gases separated to the torch  which would seem logical.

It takes a while to generate enough "Browns Gas" to have enough stock to weld with, and I'd always go with the 2 hose system otherwise, you are just waiting for it to have an excuse to "recombine" the whole thing

ajaffa1

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Re: MIG Welder, what to look for?
« Reply #18 on: May 12, 2019, 09:28:38 AM »
I used to do a lot of TIG welding when I was in the RAF, the equipment we had back then would handle a over 500 Amps using a 3/16" tungsten electrode! Had to suit up to use it, any exposed skin would get terrible arc burn, don`t ask me how I know!  :laugh:

I actually agree with you that TIG welding has a lot in common with gas welding in that you have the heat source in your right hand, while manually feeding the filler rod using your left. The difference is that you have a foot pedal with which to adjust the heat as you go. I would not recommend buying any TIG welder that did not come with a foot pedal, if that is what you are familiar with.

Make sure that the place you purchase from carries a good stock of ceramic shields, there is nothing worse than having all the equipment and not being able to use it because a shield has a crack in it. I remember putting in a military requisition for 6 ceramic shields, a month later we still had not received them. A couple of weeks later we took delivery of 6 new TIG welding plants, someone had got the wrong part number! It wasn`t me, honest. What worried me at the time was that I could order equipment valued at hundreds of thousands of dollars without anyone ever questioning it!

Bob

glort

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Re: MIG Welder, what to look for?
« Reply #19 on: May 12, 2019, 10:54:54 AM »

It takes a while to generate enough "Browns Gas" to have enough stock to weld with, and I'd always go with the 2 hose system otherwise, you are just waiting for it to have an excuse to "recombine" the whole thing

I see all these " Brave" People on YT making up these torches that use a single Cell to produce the gas where the fuel and Oxidiser are together and send it as one to a torch.

I think I'm pretty brave with a lot of things I do but I also think there is a line where the risk in brave crosses into questions of self preservation.
These people take great pride and put great effort into being able to generate upwards of 5-10 L a Min of Boom gas. There are some good Vids of these thing going Pop as well.

I lit off 100-150Ml of hydrogen in a plastic sandwich bag with some air ( let alone Oxygen)  a few months ago and that was enough to tell me it was not something I wanted to be playing around with. If I do want to depart this world and make sure the wife and daughter can collect the life insurance, I can easy do something that will only need the job doing once.  Until that time, I'll stick to 600V generators.  MUCH safer for me.

How some of these people doing Hohoho gas are still around to be doing vids after 3 years shows they are a Lot braver and luckier than I could ever be.

ajaffa1

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Re: MIG Welder, what to look for?
« Reply #20 on: May 12, 2019, 12:13:13 PM »
Browns gas is a very dangerous product, it can however be diluted with regular air to a point where you can use it as a replacement for LPG on a cooker top. I`m not stupid enough to try that particular experiment!  :laugh:

Bob

Johndoh

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Re: MIG Welder, what to look for?
« Reply #21 on: May 12, 2019, 09:58:34 PM »
It's almost impossible to get oxygen and acetylene in Ireland. You need to be a professional user like a car body shop, welding company etc. I have a small 10 year old arc welder I got in Lidl it's fine for the sort of stuff I weld and it should have died years ago. cost 59 new.
It is better to light a candle than to curse the darkness

glort

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Re: MIG Welder, what to look for?
« Reply #22 on: May 12, 2019, 10:07:29 PM »
It's almost impossible to get oxygen and acetylene in Ireland. You need to be a professional user like a car body shop, welding company etc.

Is that Due to " security" Concerns or some other reason?

mikenash

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Re: MIG Welder, what to look for?
« Reply #23 on: May 13, 2019, 08:24:00 AM »
It's almost impossible to get oxygen and acetylene in Ireland. You need to be a professional user like a car body shop, welding company etc. I have a small 10 year old arc welder I got in Lidl it's fine for the sort of stuff I weld and it should have died years ago. cost 59 new.

Most (almost all?  All?) of the stuff we now do with the MIG we did with the arc-welder 20 years ago.  The MIG has just made it fast, easy & cheap.  When it stops being cheap we can go back to the old single-phase plug-in machine

Years and years ago when I did my ticket, my instructor at the Polytech said "Use low-hydrogen rods.  They'll do a better job & they'll make you a better welder"  To do a job good enough for industrial repairs on crucial-ish machinery, you have to be able to understand the weld pool and think about what you're doing.  In later life, when introduced to the MIG, those skills are good to have.  But if you "learn" to weld with the MIG you may never, arguably, pick up those skills

I suspect there's life in the old arc-welder yet

carlb23

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Re: MIG Welder, what to look for?
« Reply #24 on: May 13, 2019, 01:34:46 PM »
i have a lincoln sp170t mig/wire feed welder that i have been using for the last 15 years or so.  Its a nice welder and has never given me a problem.

I recently attached a spool gun to do aluminum welding using argon gas.  I now use the Lincoln mainly as a wire feed machine for steel or spool gun for aluminum since i only keep i bottle of gas and it is argon.

For nicer welds i use a TIG welder.

Johndoh

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Re: MIG Welder, what to look for?
« Reply #25 on: May 13, 2019, 02:09:12 PM »
It's almost impossible to get oxygen and acetylene in Ireland. You need to be a professional user like a car body shop, welding company etc.

Is that Due to " security" Concerns or some other reason?
Im not sure Glort I tried to buy it years ago and was refused.
It is better to light a candle than to curse the darkness

glort

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Re: MIG Welder, what to look for?
« Reply #26 on: May 13, 2019, 04:34:43 PM »
Im not sure Glort I tried to buy it years ago and was refused.
[/quote]

Interesting.

I was mucking round years ago and filled a paper sandwich bag with acetylene and Oxygen.  Put it under a inverted bucked with a thin bit of newspaper for a wick.
I was amazed the police didn't show up and windows were not broken. I was standing 30 Ft away and got hit by a shock wave.  I never tried that party trick again nor did I find any trace of that plastic bucket bar the wire handle.

If one wanted to make a large " fire Cracker"  That would certainly be the way to do it.  Weld a spark Plug in an empty LPG bottle, Pressurise it a few pounds equally of acet and oxy and you would have a very powerful firework indeed. I think you could make one hell of a mess of a car with something like that.

Hydrogen and air is impressive but acetylene and oxy is something else again.

AdeV

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Re: MIG Welder, what to look for?
« Reply #27 on: May 13, 2019, 05:46:06 PM »
Acetylene is evil stuff. Anything over a few PSI and it becomes spontaneously combustive. Acetylene bottles are full of some stuff (I can't remember what it is...) which the acetylene is dissolved/contained in, to stabilise it. Even so... if you knock a full bottle of acetylene over... be prepared to RLF (run like feck), as there's an excellent chance it'll set itself alight in the bottle. Whenever there's a fire in a welding supply warehouse (you'd be surprised how often...) they close roads for 1/2 mile (~1km) around for a couple of days, because of the danger of the bottles going up. Nasty, nasty stuff.... but REALLY good for gas welding  ;D

Back to the topic at hand.... I've got both a MIG and TIG welder. The main advantage of TIG over MIG, is it's relatively easy to weld different metals (in particular, aluminium); and you can braze with it too. Most TIG welders will also do stick (arc) welding, so a ready supply of pure argon isn't totally necessary to use them. Yes, you can weld Al with MIG, but I'm told it's quite hard to do well, and of course you need the proper wire.

This Old Tony (search for him on YouTube) has done some nice videos about the merits of TIG welding; there's also some reviews by a chap called Doubleboost which are packed with information too. BTW, if you do get into ToT's videos, be prepared to lose a few days... he's really good at them.

I've never TIGged with a foot pedal - my old Murex beast (Tradestig 180 AC/DC) has a crank handle on the front of it to change the amperage... I can't even remember if I can adjust the clean vs. weld part of the AC cycle. But if you get it on song, it can turn out some lovely welds, even in my deeply amateur hands. I did, for a couple of years, try to use a Chinese AC/DC TIG, but never had much luck with it. I suspect it was faulty... you'd get a few inches of decent weld, then bugger all else except pops and farts.

MIG is much easier: Get something which will take gasless wire, but can also cope with gas if you want. Welding with gas is IMHO cleaner (no slag to clean up if you need to run over a weld for a second time), but probably not worth the extra hassle if you're not doing a lot of welding. Again, I have an ancient and enormous Murex machine with a crank on the front to set the power level (a Tradesmig, funnily enough!), but it's like spreading butter welding with it. Only a bit hotter, and less edible...

Cheers!
Ade.
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BruceM

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Re: MIG Welder, what to look for?
« Reply #28 on: May 13, 2019, 06:34:16 PM »
All this welder talk makes me jealous. The things radiate so much EMI that I have to be back about 200 feet or I'm wrecked. 

I've even watched some 2 and 3 car battery welding vids- but wonder how continuous the arc really is; if it's interrupting regularly, it's not really DC, and will be broadcasting EMI. A spark is the perfect broad spectrum source, and connected to wires it makes a dandy transmitter of some serious power.  All the battery setup needs is 3 batteries and some linear regulation of current, which I could do, or perhaps 2-12V batteries and one 6 V.  36V is too much, 24 to little.


AdeV

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Re: MIG Welder, what to look for?
« Reply #29 on: May 13, 2019, 07:31:36 PM »
Bruce - are you sensitive to EMI anywhere, or is it (for lack of a more delicate term) all in your head? By which I mean... if you made yourself a Faraday cage welding helmet, would that enable you to weld without problems?

If it's an "anywhere on the body" thing, a suit of armour might be the solution (suitably grounded of course!)  ;D
Cheers!
Ade.
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1x Lister CS Start-o-Matic (complete, runs)
0x Lister JP4 :( - Sold to go in a canal boat.