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Arc or Mig welding, very confusing!

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Jackbequick

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Did a limited amount of stick years ago. I was welding a boat trailer one day when a big lump of spatter landed on the tongue of my trainer (I know! I was young and foolish), leading to my first and only breakdancing performance… 😊

+1 for the MIG welding Forum. Great resource. I see they're still partnered with/sponsored by Weldequip, who gave a good service when I bought stuff from them.

A recurring theme when I was searching for advice on buying a MIG was to make sure it had a decent wire feed, otherwise I might struggle as a novice, and to make sure it had a standard Euro torch, as spares and consumables are cheap and readily available. The thing I’d add is if possible try and get something that doesn’t have a fixed earth lead. It’s a pain in the a***, and you might find you’re moving the welder around with annoying frequency on bigger jobs, and a real problem if you need to weld anything such as brackets at or above head height!

I’m no expert, but did do a fair amount of welding after buying the MIG, and found the following useful:
  • Auto-darkening helmet. You can also get magnifying lenses, which is great if your eyes no longer work like they used to.
  • MIG gauntlet for non-torch hand, and a thinner TIG glove for your torch hand will give a better feel for controlling the torch.
  • Using Tip Dip, and keeping the shroud nice and clean.
  • Flap discs (essential).
  • If fabricating from scratch, a second grinder is useful. Continuously switching between cutting discs and flap discs gets annoying, quite quickly.
  • If you’re in a small workshop, you might want to consider a couple of welding blankets. My workshop is tight on space, with stuff stored under the benches and in racking, and generally cluttered. If a bit a of spatter finds its way into a place you can’t see, you don’t want your workshop catching fire half an hour after you’ve finished and gone indoors for a brew!
Have fun.
HI...some very good advice there...

Circumspect of Chinese gear I nevertheless grabbed an 'electronic' helmet recently at Bunnings ...$49.00...interestingly the boiler maker who recently did some work for me had the same type of helmet...look a bit like a speedster helmet.

One thing...may sound pretentious I suppose...good welding shouldn't need grinding. When it is done you no longer really know the penetration which has been achieved and thus the strength. Having said that (you'd know it) , using the grinding tools before welding is a key to success in what one produces....not just 'preparation' but 'correct' preparation for the weld.

I noted with the boilermaker aforementioned, that occasionally he made almost imperceptible adjustments to his MIG (current not speed) during his various welds on same situation ..."just a tad, so fine'...that so-expert feeling he had developed over decades for having the flow "just so" with same sound of the arc all along. None of the welds needed prettying-up. "Funny" how fascinating it is to listen to that consistent sound and see the results of expert welding...admire the skill.

On the other hand I watched with some 'dismay' a 'past- retirement' professional aluminium welder, who makes boat and jet-ski trailers, grind-away copious welding material. Maybe the trailers hold together, maybe not. I wouldn't buy one having watched the operation. I always look for a very neat and consistent weld with correct penetration...nothing needing to be hidden.

I think I'd need a metre of practice to achieve it these days!
 

Redkite

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Full of advice and tips on all things welding for beginner. My vote would be a 180 amp R-Tech tig running Argosheld or Hobbyweld gas.
Another +1 for the welding forum, also covers arc welding, lots of good advice for beginners on techniques, equipment etc, definitely well worth looking at.
 
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Spectric

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As a total beginer and I assume no experience then the good old stick welder is a good starting point. Simple setup, only current to set and you want to weld what I would class as agricultural. Then if you want to progress I would suggest an evening class as you really need some theory as well as practical. MIG welding is ok if you get a decent welder that has the power, but it is easy to get a nice looking weld with little penetration. Modern invertor MIG welders are also a lot easier to setup than the older transformer types. Then you have TIG, my personel favourite and this is easier to learn if you have gas welding experience as you already have rod feed experience and using this process you can weld anything that can be welded.
 

Ttrees

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That's not to say you can't make an invisible joint with the arc though.
Just not anything that's sub 2mm.
 

Jelly

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Secondhand AC stick welders are even cheaper but that is because they are useless.
Whilst I have access to big, 3-phase EASB MIG and DC Arc welders if I need them, the 140A buzz box I bought for £30 (for the £150 worth of high nickel content rods which came free with it) is generally sufficient for my needs to occasionally fabricate brackets, stands and the like.

So I would very much challenge that they're useless!

The old AC only units have their place but if the user doesn't understand the limitations, they will be endlessly frustrating to operate.


The biggest limitation is that AC Arc welding requires more control and finesse from the operator to actually start and maintain the arc, which is broadly incompatible with their position in the market as bargain basement entry level machines.

The reduced penetration compared to DC has to be considered too, but can be mitigated by appropriate joint design and prep, it's also occasionally a benefit (say when welding dissimilar thickness materials).


Overall the Oil filled AC units are pretty good for someone who welds infrequently and can't justify a lot of expense on a welder, but needs a machine to weld thick plates or do anything else which requires sustained periods of welding to deposit a lot of material.


The "Buzz-Box" air cooled types have pathetic duty cycles, but if you need to make short welds, and use it once in a blue moon they're fine for the price, I wouldn't want to spend much over £50 for one in good nick though.
 

highwood122

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heimlaga is not quite correct to say second hand ac stick welders are useless, if you can find one with open circuit voltage of 80v or 100v they are ok
 

hawkeyefxr

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To give an idea, a boilermaker who recently did some work for me used and an ancient 180A gas-less MIG. You may be aware that boilermakers especially having been approved with X-Ray are the cream of welders.Getting the current spot-on is a great part of good welding however penetration and width of weld are what gives the strength.

MIG users more so than stick welders use one (gloved) hand to support the other. Looking at how the molten metal is running and not rushing ahead is crucial.

A well fitting helmet (maybe electronic) can cut out one of the nuisance aspects of welding.

Try not to inhale the fumes.

Stick welding definitely has its place and it is not a poor welding method whether in ac or dc. That same (tradesman) welder of whom I spoke , has had a lifetime of expertise on pipelines etc.

For stick welding he uses a unit about the size of two fists. That took me aback...really?...what cycling?...'continuous' he said......wow!!

My portable stick welder is driven (ac/dc ) by a Fordson tractor engine!

Lumpy welds are likely to be weak. My suggestion is as one comment said...practice, practice,practice (each day) on the channel in a piece of angle iron....to relax, steady hand, control breathing to 'normal'. Look for examples of excellent welding and listen to 'how'...and by the way the welding 'sound' tells how well you are going....or perhaps do a welding course at Tech...there may be a short term course...or pay a welder to teach you.
Also try vertical and overhead for a challenge, remember not all jobs can be turned over easily.
 

Spectric

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I cut my teeth on a big old oil filled Oxford stick welder and once mastered it could lay some very decent welds, providing the joint was preped and the rods dry, Stubbs rods were one of my favourites as the slag came away nicely to reveal a sound weld and it was always fun doing vertical up welds, as you said not everything can be positioned to suit the welder.
 

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