arc welder?

[oscar13]

http://www.machinemart.co.uk/shop/product/details/clarke-190n-easi-arc-welder


http://www.halfords.com/webapp/wcs/..._productId_269739_langId_-1_categoryId_255210


after some talks with my mums fella who is a plumber ive been told to start off with an arc welder as it will be easier to learn with and wont cost as much to buy or maintain.

could people give advice/opinions on the above please.
i know halfords wont be the best place to go for a welder but i can get it at trade so just keeping options open really.
cheers

 

[keith19]

You realise that neither of these machines will weld metal thinner than about 2 - 3 mm?

Mig is much easier to learn than arc, and will weld thinner metal. But generally more costly to start with.

However, if you only wish to weld thicker metal, arc is a good skill to learn.

Of your two machines, the Clarke has the larger range, but will blow 13 amp domestic plug fuses used over about 140 - 150 amps, so unless you have a 20 amp plus supply this m/c will be useless at the top end.

The SIP from Halfords is not nearly so powerful, but can be used from a domestic socket probably all the way through its range. It may blow an occasional fuse if used flat out on a domestic socket, but is more likely to run out of breath first.

I take it your mums fella does not arc weld? Or if he does, he may have forgotten how long it took him to learn. Arc welding, particularly with these 'buzz-box' type of machines, is quite difficult to pick up quickly, unless you attend a course or have a mate who can advise you.

You need to do a lot of practice on scrap metal of various thicknesses before tackling a real job. You have to persevere and practice often, till you feel okay with what you are doing.

And whatever you do, start off by buying good-quality welding rods, not the chinese cheapies from halfords, b & q, aldi, or screwfix, etc. Good rods will make the learning process very much easier. Cheapie rods are usually grim for an experienced welder to use; they are hell for a beginner!

Any problems, post them up here with pics, and you'll have lots of helpful advice.

 

[Wozzaaah]

Tell your mum's fella not to give up his day job.
He's talking out of his 'arris I'm afraid, arc welding is far more difficult to learn than 'point and squirt' mig welding.
Get a mig and be done with it.

 

[oscar13]

Will a 1.6 mm rod not be capable of doing things like sills or body panels on cars without putting holes in it? In a bad way. So mig is what i should go for then?

 

[wigwan]

Will a 1.6 mm rod not be capable of doing things like sills or body panels on cars without putting holes in it? In a bad way. So mig is what i should go for then?

im no expert but i have done some arc welding and a little bit of mig and as said arc is harder to master and mig is more usefull, arc imo would be no good for car sills and wont be any good for car panels, tell people on here what stuff you will be welding and someone will be able to advise you.

cheers

 

[Wozzaaah]

According to a former member who was forever getting shot down in flames for his attempts then yes, an arc welder will weld thin steel as long as you don't mind it looking like it's been sat in a pigeon loft for 6 months and you have shares in a grinding disc manufacturing company but according to the rest of us who live in the real world, no, it won't, so MIG it is.

 

[bigtip]

i heard years ago that arc was not legally allowed for car repairs but whether or not that is nothing but urban legend, no-one that i've ever heard of uses it on cars.

anyway, arc welding in the flat position with good rods is one thing but upside-down position, which you would need to do a sill, is not a skill that you will learn easily. mig is so much more forgiving out of position and defo the right machine for the car panels.

 

[keith19]

Having used both arc and mig for replacement panels and patches on cars and vans in the past, I would never even think of trying to use arc if mig or gas was available.

When we arced in floorpans and heavy duty panels in the 1970's the metal we were using was around 1.6 mm (16 gauge), and the rods were 1.6 and 2 mm; and tack it in, then short runs of about one inch and miss two inches, were the order of the day. Today most panels are much thinner, so arc is out of the game anyway. And as already said, for positional welding like underbody work, arc is very difficult to use, even on heavy chassis, unless you are able to lift it or tilt it high enough to get good access.

 

[PTvor]

i heard years ago that arc was not legally allowed for car repairs but whether or not that is nothing but urban legend, no-one that i've ever heard of uses it on cars.

I've been told that and I believe it's B/S. It's just that arc isn't practical for most car welding especially with cars of the past 20 years or so with increasingly thin metal.

 

[keith19]

Originally Posted by bigtip.
i heard years ago that arc was not legally allowed for car repairs but whether or not that is nothing but urban legend, no-one that i've ever heard of uses it on cars.

Yes, it is B/S. The arc temperatures of both stick arc welder and mig arc welding are similar, so their effect on the metal will be much the same. I think this urban legend came about because of some of the arc-welded jobs presented to MOT garages years ago by chancers were full of holes or pigeon-poo, or both. So they were probably told the jobs were illegal, which made them think that arc technique was also illegal.

 

[bigtip]

again, i'm not claiming it is anything but urban myth, but the reason i was told was due to 'brittleness'. whether that applies to the parent metal or the weld itself i don't know. anyone know if there is any difference in 'brittleness' between mig and arc? just out of interest..

 

[keith19]

All arc welding causes the resulting weld to be more 'brittle', as you say. The heat affected zone around the weld tends to be more brittle than that around a O/A gas weld, as well.
The weld when cold is much harder than the parent mild steel. Usually this doesn't matter too much. The difference between mig arc welding and fluxed rod arc welding, as regards weld hardness, is very little. Gas wire mig welding is slightly cooler, especially when using argon mix, but the weld will still rank alongside an arc stick weld for hardness.
Compare these to a gas weld and the difference is immediately obvious - the gas weld can be 'dressed', or worked, even when cold. The arc weld can only be ground down.

 

[PTvor]

again, i'm not claiming it is anything but urban myth, but the reason i was told was due to 'brittleness'. whether that applies to the parent metal or the weld itself i don't know. anyone know if there is any difference in 'brittleness' between mig and arc? just out of interest..

Sounds like more tosh. Car bodies, and chassis where you've got them, are mild steel and can't be tempered. The weld metal is also mild steel. Even rubbishy mild steel welds are ridiculously strong and not at all brittle for most purposes. Brazing is forbidden for anything structural.

Car restoration is largely about cosmetics.

 

[keith19]

PTvor, I'm a bit surprised by your reply to bigtip.

Have you never tried to dress an arc-welded seam on thin metal? You will find it's almost impossible to do without the adjacent plate bending first. Arc welds are heat hardened considerably when compared to O/A gas welds. This might not make them brittle in the normal sense of being like glass, but it means they are a great deal less malleable.
The lower temperature difference of the gas welding process leaves a weld which is more malleable, so more easily worked. I speak from personal experience in a bodyshop, by the way.

 

[Lawnmowerboy]

interesting thread this, i've been welding in landrover series footwells for the last two days and had some interresting positions, but i think im fairly proficient in mig welding now though i may say myself!
but anyhing under 2mm mig all the way i have owned 4 arc welders, an aldi one which blew up a screwfix one which did the same a sealey thing that melted its windings and my current and best cemont blumaster 130 and some low hydrogen rods does a lurvely job but yeah a mig is the best way for any general welding below about 10mm

 

[brightspark]

interesting thread this, i've been welding in landrover series footwells for the last two days and had some interresting positions, but i think im fairly proficient in mig welding now though i may say myself!
but anyhing under 2mm mig all the way i have owned 4 arc welders, an aldi one which blew up a screwfix one which did the same a sealey thing that melted its windings and my current and best cemont blumaster 130 and some low hydrogen rods does a lurvely job but yeah a mig is the best way for any general welding below about 10mm

try oxy acetylene gas welding u dont know what u are missing

 

[bigtip]

true, the restoration of cars is mostly cosmetic but the structural parts are subject to the same MOTs as any car, young or old. the ability to harden steel is sort of related to it's carbon content and all steel has some carbon which is what makes it steel so it can become relatively 'brittle' or 'malleable' by engineering standards depending on how you treat it.

i like oxy acetylene welding a lot but isn't it slow though? (and expensive if it's you that has to pay for the gas bottles!).

 

[keith19]

Yes, it is slower than mig, which is why it fell out of favour for general garage body repairs, where jobs have to be shunted through as quickly as possible.

But a good many high-class car restorers still use it, because a good gas-welded repair can be planished or dressed down into the surrounding metal so that there is no visible sign of any patch or repair, all without using any kind of filler. I take off my woolly hat to guys who can work to these standards, they are true craftsmen.

You just can't do this with mig welds, they are too hard.