Welders, explain them to me please...

Been thinking about getting a welder, and learning to weld, had a look on machine mart, and bewildered about what to get.

For a start, arc or MIG, I thought it was the same difference, but obviously not.

Gassless, how does that work then, and are they any good, or do they need a special rod/wire or summat?

what output, somone recently told me a 100A would be fine for most stuff.

timtheenchanteruk said:

Been thinking about getting a welder, and learning to weld, had a look on machine mart, and bewildered about what to get.

For a start, arc or MIG, I thought it was the same difference, but obviously not.

They are except mig uses thin wire and a gas to provide the shielding. Arc uses thicker rods, with a flux coating to provide the shielding.

Gassless, how does that work then, and are they any good, or do they need a special rod/wire or summat?
Same as a welding rod, flux is coated onto the wire so doesn't need gas to shield it.

what output, somone recently told me a 100A would be fine for most stuff

Bigger really is better, with a mig welder. at least 150amp prefferably 190amp speshully if ya wanna weld thick stuff..

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The above info is my opinion not gospel..

hi tim i am a welder by trade and you want a mig not arc, and dont go gasless they are crap! i have got a 150 amp wolf mig from screwfix and it has been good for home use not like the 400 amp i use at work! a 100 will do but if you do overhead work you may have problems, you will have to think about voltage loss if you are using a long extension lead as well. the main thing with welding is practice and make sure what you are welding is as clean as you can get it. and buy a reacting mask as well £35 quid on ebay you wont regret it, hope that helps a bit Dave

cheers, link in yer sig is helpful too :biggrin1:

arc is fine for proper bits of metal over about an eigth of an inch thick .... its too fierce for bake bean tins and car bodies... for thin sheet steel you need a mig that will go down to below 50 amps some of the cheap ones dont.
ive had a 180 amp arc set for years and can weld half inch plate with it... ive recently bought a 130 amp mig for the discovery rot.., which im using gasless, .. i dont need a big mig cos ive already got the arc set.

Is gasless really that bad? If so, why?

lorri789 said:

Is gasless really that bad? If so, why?

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Only if you're an Annally Retentive twot.. Have used both and their isn't any differnce in weld strength. that I can see. I welded the new rear crossmember on me old 90 and used it to pull a few peeps out of the **** and towed trailers and me overloaded Pikey wagon, from Hull to Yeovil.


Awaits outraged ****ers telling me how so much better it is and even which gas is best.. :yawn:

I see. So it's like mig snobbery or something.

lorri789 said:

Is gasless really that bad? If so, why?

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It's not bad.....slightly more difficult for beginners cause you can't see the pool as well and tends to be a bit more splattery but makes a good weld

lorri789 said:

I see. So it's like mig snobbery or something.

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Yep

redhand said:

Only if you're an Annally Retentive twot.. Have used both and their isn't any differnce in weld strength. that I can see. I welded the new rear crossmember on me old 90 and used it to pull a few peeps out of the **** and towed trailers and me overloaded Pikey wagon, from Hull to Yeovil.


Awaits outraged ****ers telling me how so much better it is and even which gas is best.. :yawn:

Click to expand...

Hee hee, I'm also a qualified welder etc, 400 + amp 3 ph etc etc etc, however, at home I have a 250amp Arc, a 200amp Tig, and a 180amp Mig. The Arc is hardly ever used, unless it's bloody enormous stuff..The Mig will weld just about anything, It's dual purpose, meaning gasless or gas, personally I prefer gas, the mix over here has a small percentage of pure oxygen and increases the temp, handy for big stuff.
I've used it outside with the fluxed wire and it worked perfectly..
If it's a bit draughty where you are welding the fluxed wire is probably the best bet, and get the biggest Mig you can sensibly afford with fan cooling.

I'd definitely say mic over arc. I've not done much arc but from what I have done all the coke residue crap really doesn't help with nice welds.

There are other things to think about though before making your choice. Like whether to pay more for an AC set (in case you ever want to weld aluminium) or whether a DC set (steel only) will suit you. The torch socket being a euro standard plug in one (I forget what its called) rather than built in is a nice to have (most of the machine mart ones aren't). There are welding forums that have articles on this stuff.

Definitely buy a reacting mask, and get the best you can afford. Its makes a heck of a difference if you're pointing it in the right place when you start. I tend to use a reactive mask and hold an inspection lamp under the torch so I can see what im doing when I start. Best to try out the mask if you can. The first one I bought wasn't adustable and gave me a bit of arc eye.

I've never used gassless so can't really comment on that. From what I understand it uses a fluxed wire instead of the gas sheild. If you go gas you will need to consider openning a rental account with one of the companies. Those little disposable gas bottles don't last long from what I've heard.

The amp rating is mainly to do with the penetration. So it determines the thickness of steel you can weld. I have a 180 amp, which I've used very successfully for 4mm steel and I'm sure would be ok for 5mm. On a landy (chassis is what 2.5mm?) a 150 amp might be enough. The welder specs tend to give a max thickness.

Also, you want overalls, a welding apron and gauntlets, A wire brush and steel side cutters. Preferably dont weld in trainers if poss, I once set fire to my foot.

I'm a fabricator too. Little tip - buy a 70mm rotary wire cup brush thingymajig for an angle grinder to use for cleaning welds and prepping once ground out.

I can eat my dinner off my weld preps and it makes a decent difference. It gets rid of grinding dust and the powdery residue from grinding disks and also any impurities and **** from any tacks. Just gives the best chance of max penetration for those not so proficient at welding. Using it post weld also brings the weld up a treat once de-spattered.

cheers guys, plenty to think about there, Re the gas rental, Ive been told there is somwhere local to me that still does the old fashioned method of bottle deposit, so no rental.
For the amount i would be doing, rental would be bit overkill, so it would be deposit, or disposables, I know a few folk with rental bottles who could possibly get me one for a bit if I had a lot of welding to do.

the gas /gasless thing depends a lot on what yer going to be doing.... my mig basically comes out twice a year... disco mot and fourtrak mot time.... im putting patches on bits underneath... and splattering on layers of underseal stuff as well. so basically nobody is going to see the welds anyway..... gasless works i aint got the expense of gas bottles... or the agro of it running out in the middle of the job. i weld outside so gas blowing away inthe wind is a consideration.

if youre welding professionally every week in a draught free workshop with customers looking at your work gas is probably the better option.

my machine will convert to gas should i want to use it.....

for occasional use a £150 machine will do the job why pay megabucks for a pro spec outfit that you wont see any benefit from.


i wear wellys with a cotton boilersuit hanging over the boots so hot bits cant go down the boot leg....but if yer on yer back under a vehicle feet are well out the way so shoes aint as issue, gauntletts are a must. ive been using a old fashioned hand held dark glass mask for best part of 40 years , dont now do enough to think about lashing out on one of them new fangled lectronic reactor masks....might change me mind if i actually get to use one..

always have a bucket of water nearby to chuck on anything smoking
and recheck for smoke 15 minutes after youve finished.

MIG Welding Forum

Have a look at this website, it was recommended to me a while back by several people on another forum and it's very useful.

There is lots of information on everything you can think off, alongside some very good tutorials also including spraying.

The basic things I picked up from it were:
Gas is easier to learn with than gasless
Buy the best welder you can for your money (2nd hand high quality is better than new)
Get an auto-dimming mask, it makes everything so much easier
Euro torch is a desirable feature
Fan assisted gives a better duty cycle (you can weld for longer at once)

Gas can be quote expensive from somewhere like BOC, especially if you won't use it much. There are companies where you buy the bottle then just pay for refills. It is possible to weld with pure CO2 rather than argon mix, A few of my friends use pub gas bottles (get friendly with your local, cover the cost of a re-fill and they will generally lend you a bottle) The latter works out about £12 for a full can.

What is your budget for a welder and all the other little bits?

HTH, Harry

Another tip - the wire feed units on hobby welders are generally poor so keep the lead to the torch either as straight as you can or introduce a nice big natural curve. Avoid letting it loop over itself.

As for welder selection, mug over arc without doubt for car work and positional welding. Can't comment on gas or gas less as I've never used gas less but if you're working outside then this may be something to consider.

Mug?

**** off iPhone.

ah, never thought of that, i presumed that it had to be an argon/CO2 mix, if just CO2 is ok, I have a couple of big cylinders of that I use for CO2 confetti cannons

redhand said:

Only if you're an Annally Retentive twot.. Have used both and their isn't any differnce in weld strength. that I can see. I welded the new rear crossmember on me old 90 and used it to pull a few peeps out of the **** and towed trailers and me overloaded Pikey wagon, from Hull to Yeovil.


Awaits outraged ****ers telling me how so much better it is and even which gas is best.. :yawn:

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On very heavy plate I use 1.6mm flux cored with gas(argoshield heavy), better penetration and less thermal shock.
If you can weld it makes no odds if you use gas or gasless