Cheap MIG vs. cheap TIG for fabrication

[murpia]

Hi,
Mainly for the UK teams (I'm UK based) but feel free to chip in with your opinions. For basic fabrication duties on a budget has anyone experience of the trade-offs of using a cheap MIG welder vs. a cheap DC-only TIG welder?

The kind of equipment I mean is shown here (MIG) (http://www.machinemart.co.uk/shop/product/details/110e-mig-welder) and here (TIG) (http://www.machinemart.co.uk/shop/product/details/arc-tig-85-power-inverter) which needs an additional kit (http://www.machinemart.co.uk/shop/range/details/tig-arc-welding-kits-for-arc-tig-inverters). Both are bottom-of-the-range units.

Or, is it better to spend the budget of the TIG set on a better MIG (http://www.machinemart.co.uk/shop/product/details/150te-turbo-mig-welder)?

This is for a one-off project so equipment longevity is not a priority. I'd prefer to learn to TIG but not if it's a waste of effort with this level of equipment.

Regards, Ian

[murpia]

Hi,
Mainly for the UK teams (I'm UK based) but feel free to chip in with your opinions. For basic fabrication duties on a budget has anyone experience of the trade-offs of using a cheap MIG welder vs. a cheap DC-only TIG welder?

The kind of equipment I mean is shown here (MIG) (http://www.machinemart.co.uk/shop/product/details/110e-mig-welder) and here (TIG) (http://www.machinemart.co.uk/shop/product/details/arc-tig-85-power-inverter) which needs an additional kit (http://www.machinemart.co.uk/shop/range/details/tig-arc-welding-kits-for-arc-tig-inverters). Both are bottom-of-the-range units.

Or, is it better to spend the budget of the TIG set on a better MIG (http://www.machinemart.co.uk/shop/product/details/150te-turbo-mig-welder)?

This is for a one-off project so equipment longevity is not a priority. I'd prefer to learn to TIG but not if it's a waste of effort with this level of equipment.

Regards, Ian

[Brian Evans]

A lot depends on what you are welding, both in terms of material type and thickness, and mechanical structure. If it's fencegates, outside, and 1/4" steel strapping, then a flux-core Mig would be my choice.

If it's thin wall tubing, steel, below .065" wall thickness, mitred joints, inside, and speed is not an issue, I'd choose the Tig. It won't be easy to learn how to get those to go (scratch start, probably not a lot of current control) but it sure can be done.

The traditional British way to fabricate light structures in steel is nickle-bronze welding, you could try Sif-Bronze #2, flux coated, and learn that skill as well...If you every go to the Motorcycle Museam near Birmingham there are racing bikes by Rickman that are Reynolds tubing and nickle-bronze - never painted, bare metal, works of art...

Brian

[markocosic]

That Clarke MIG is massively overpriced in my opinion.

Things like that are worth a punt when you find them in LIDL/ALDI for £50, but I would presonally skip the whole £150 section and go for the £250 'backstreet garage' grade MIG that takes the 5kg reels.

It'll weld anything up to 1/4" plate, you can weld for more than two minutes at a time without it dying on you, you can put a proper gas bottle in there rather than an expensive disposable etc - but the biggie is that the wire feed is soooo much better that it'll make for far smoother/easier welding than a toy machine.

If it's for general fabrication work (including production car car bodging, locost/se7en building, land-rover and 2cv chassis etc) and you don't mind a little spatter, head to your local pub and acquire a CO2 bottle. (make sure that it is plain CO2 and not NitroKeg Nitrogen/CO2 mix) I pay £7 to get mine refilled (7kg) as versus £10 for 500g for those hobby bottles.

Absolutely /useless/ for anything under 1.5mm thickness though.

[NetKev92]

MIG's reputation is that it's a fast method to weld large parts and significant thickness. The method is not exceptionally precise although a good welder (the technician, not the machine) can do a lot to help. Sport Compact Car has displayed roll cages that were MIG welded into cars beautifully.

TIG is a slow manual process very similar to gas welding except the heat source is electric arc. With an Argon bottle and a decent machine, TIG is the preferred method for thin wall steel or aluminum unless you're an old-school type who likes gas welding.

Gas is still popular in aircraft. It gives the precision of TIG at half the cost or less. There are some very cool small gas torches available for welding thin wall aircraft or racecar tubing. With the right filler rod, aluminum welding is an option. A good large torch also allows the ability to perform some heat-treating operations.

With either electric method, you'll either need shield gas or flux-core wire. Shield gas is the purist's choice because you don't add impurities to the weld. Flux core wire allows you to get along without shield gas, but strength is typically lower and the welds aren't as pretty. If you can find a class or somewhere to mooch on a machine, try each method and decide what you like. They teach gas and TIG at the Oshkosh airshow in the states. I got TIG with a family member and split the cost because it was twice as expensive as a good gas setup or MIG. I ruled out MIG for myself on the recommendation of people I've worked with. Aircraft builders typically tell you not to even consider MIG. MIG spools feed the wire at a steady pre-set rate, and working the tight spots in a tube cluster with the ready-or-not spool gun of a MIG could be an iffy situation. I chose slow and precise.

Take a look at Kent White's Gallery and gas welding stuff. He's the best sheetmetal bodywork guy I've ever seen. He often teaches metal shaping at Oshkosh and occasionally teaches aluminum welding with gas.
http://www.tinmantech.com/html/kent_white.php

[John Stimpson]

In my experience, you should never buy a super cheap welding machine. They are all crap. Yes, they can be made to connect 2 pieces of metal, but thats it.

If you *must* get a cheapie, get the MIG, and spend as little as you possibly can, because any money you spend on a crappy little welder is money down the toilet.

As a minimum, get a 220V 175amp MIG machine, that accepts gas bottles, NOT JUST FLUX CORE. Miller and Lincoln both have machines in this range, and they're around $1500. Definately opt for the infinitely variable voltage and wire speed controls. Some have knobs with discreet detents...crap.

Honestly, if I was not wanting to spend any money on a welder, I'd buy the leads for a stick torch, and weld using a couple 12V car batteries wired in parallel.

I've done a lot of welding, and used lots of different equipment, and cheap welders are just not the way to go... And I'm a *very* frugal person.

[NetKev92]

If you watch for a discount or maybe work Lincoln Electric for a student deal, you can get a 220V 225A TIG like the Precision TIG 225 for $2200 with cart and a bunch of the extras.

In gas, $500 ought to be enough to get one good torch, bottles, and a cheap auto-darkening helmet.