Author Topic: MIG Welder, what to look for?  (Read 7345 times)

guest23837

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Re: MIG Welder, what to look for?
« Reply #15 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.

mikenash

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Re: MIG Welder, what to look for?
« Reply #16 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 #17 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.

guest23837

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Re: MIG Welder, what to look for?
« Reply #18 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.

AdeV

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Re: MIG Welder, what to look for?
« Reply #19 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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0x Lister JP4 :( - Sold to go in a canal boat.

BruceM

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Re: MIG Welder, what to look for?
« Reply #20 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 #21 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.

BruceM

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Re: MIG Welder, what to look for?
« Reply #22 on: May 13, 2019, 08:13:21 PM »
My head is a significant target for strong magnetic fields (near field in EMC parlance) - so back before I learned that air tools would solve it, I used to try and use a drill keeping my head as far away as possible...it increased my working time but wasn't very practical.  For electric fields, it seems anywhere goes.  I've tried see through metalized fabrics and even an aluminum foil helmet with holes for eyes...they don't do much...too many openings and slits.

Some of the earliest reports of electrical sensitivity in Sweden were cell phone design engineers.  One of them had a full bee keeper's suit with metalized fabrics and silver thread fabrics.  Hardly conducive to an improved social life, but I understand the desperation. I haven't gone that route as I find the metalized synthetic fabrics stink bad enough to bother me, and can't imagine wearing it for a long time. 

My only interesting finding of late is that the blood thinners for my DVT have markedly improved my latency and decreased the severity of symptoms- which where always pressure headaches followed by cognitive impairment and eventually complex partial seizure or absence seizure.  Perhaps venous blood flow from the brain is being effected.
 
SPECT scans of people with electrical sensitivity look much like a closed head injury...only they didn't have the physical injury...just the identical pattern of areas not getting blood flow.


guest23837

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Re: MIG Welder, what to look for?
« Reply #23 on: May 14, 2019, 12:19:43 AM »
I have read mixed reviews on gasless mig welders  I'm curious as to the truth. I was looking at a few gasless welders and some inverter welders. I saw a guy doing what looked like magic with an inverter welder on a rusty exhaust now that's beyond my skill level ! Anyone with gasless or inverter that wants to add their 2/- Id be interested in reading it.

guest23837

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Re: MIG Welder, what to look for?
« Reply #24 on: May 14, 2019, 01:03:40 AM »
Years ago you could put a little carbide and water in a paint tin with a pin hole in the lid. give it a shake and then throw lighted matches at it. It made a very impressive bang. I haven't seen carbide in many years.

AdeV

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Re: MIG Welder, what to look for?
« Reply #25 on: May 14, 2019, 06:56:15 AM »
Years ago you could put a little carbide and water in a paint tin with a pin hole in the lid. give it a shake and then throw lighted matches at it. It made a very impressive bang. I haven't seen carbide in many years.

I'd like to get hold of some carbide myself.


Here in Europe, at least, it seems you can buy it on eBay!

https://www.ebay.co.uk/itm/Calcium-carbide-lumps-CaC2-500-g/263817124663
Cheers!
Ade.
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1x Lister CS Start-o-Matic (complete, runs)
0x Lister JP4 :( - Sold to go in a canal boat.

cobbadog

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Re: MIG Welder, what to look for?
« Reply #26 on: May 17, 2019, 01:03:52 PM »
With my MIG I initially set it up to run gasless. I agree with glort that penetration is not an issue as it does bite in. My issue was probably me. I simply could not get a flatter weld, it taught me how to grind off excess weld. Again I say the issue was possibly me and being a learner as I had never used a MIG before ever. Watched a lot of YouTube videos which were helpful but in the end I went to Bunnings and went with their idea of running gas and not having rental. So I switched the polarity over and connected the gas and away I have gone with pretty fair results just what I was expecting a clean weld and a flatter fillet.
My unit is a Lumig made where else but China but it is a little beauty. It can also be used as an arc welder and is an inverter for that purpose but never tried it. I have a separate arc welder which is an inverter and it has impressed me so much that I sold the other 2 welders with big heavy coils inside for others to learn on. Inverters are very easy to use as well and are easy to strike the arc to get you going.
I too have been using the unbranded coils of wire both gas and gasless and they seem to perform well. One day when I have run out of things to do I will once again reverse the polarity and put the gasless wire in and have another go at it. I am not writing it off in case it is as expected, operator error, plus it would be a big bonus to use gasless when welding the rust up on the "A" pillar of our Lorry as wind will play havoc with the gas.
Coopernook - the centre of our Universe.

mikenash

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Re: MIG Welder, what to look for?
« Reply #27 on: May 17, 2019, 11:45:24 PM »
i also don't mind cheap chinese stuff . I have had an EXCELLENT run from what I have bought and some of it has been thrashed to the point if it fell over long ago i would have bought another saying I got my moneys worth from the first lot.
Thing is, If i'm buying Chinese gear I want to be paying Chinese NOT premium prices. That's the tradeoff for the risk you take.

Service and backup is important as well but the reason I stopped buying Dewalt tools was because you pay through the nose for stuff made in China that does not last any better and the warranty/ service/ standby from the company is crap.

Be interesting to see the warranties on the things as well.
I think the relevant questions that need to be asked go well beyond amps and duty cycle and all the rest of the numbers and probably applies to most other things as well.



"Ozito"  is the word you are looking for

We have Ozito tools at work.  Not flash but big & solid & they work & work

We paid $130 eight or nine years ago for an Ozito hammer drill from Bunnings.  It has drilled many hundreds - more likely thousands - of deep 20 or 24mm holes in concrete for tru-bolts or chemset.  I drilled forty or fifty or sixty 20mm holes with it one afternoon.  I was knackered but it was still fresh

When it finally died late last year we just went to Bunings and paid $140 for another one

I have one of their routers and an electric planer - both cheap and good.  The $70 planer did all the work involved in true-ing up all the subfloor structure when I put a floor in a 70M2 shed last year - if I had thrown it away after that it would still have been a good deal

I'll be asking where they are made that is for sure.
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ajaffa1

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Re: MIG Welder, what to look for?
« Reply #28 on: May 18, 2019, 12:55:04 AM »
Hi Guys, when I was on the tools in the UK, I would only buy Makita tools. The reason for this was that their spares department was second to none, same day dispatch with guaranteed delivery the following day. I don`t know if they sell any welding equipment but it might be worth a look.

Bob

BruceM

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Re: MIG Welder, what to look for?
« Reply #29 on: May 18, 2019, 04:28:43 AM »
I spent quite a bit of time researching direct battery powered DC welding.  Clean DC the way i like it; I'm a charter member of the Church of Edison.  ;)

Seems 2 good batteries plus a big DC choke does an acceptable job up to 1/4 steel at around 120 amps.  The choke, around 300 uH or better is essential as a current limiter/regulator and keeping the arc going.

A guy on a welding forum in 2007 did a lot of experimenting and documented his work pretty well.  Alas, he didn't have an electronics background and didn't realize that he was saturating his ferrite and other cores at his welding current of 90-125 amps, and his test values were  using with an LCR meter that only gives the unloaded inductance.  His choke weighed 40 lbs, largely from copper windings.

I may give it a shot, but it does mean unwinding and gapping a 1000w or bigger toroidal transformer core for the choke.  I'll have to crack some books to estimate the number of turns to avoid saturation at 140 amps. 



« Last Edit: May 18, 2019, 04:31:33 AM by BruceM »