Welding tools: names, pictures and what each one is used for

Pick the process, then the machine

There are three processes worth considering at home, and they suit different jobs rather than different budgets.

MIG feeds wire automatically, so it is the easiest to learn and the fastest on clean steel. Stick is the most tolerant of rust, wind and thick metal, and the cheapest to get started with. TIG gives the most control and the neatest result, works on aluminium and stainless, and takes the longest to learn because both hands and a foot are all doing something.

Most people should start with MIG on thin to medium steel, add stick if they work outdoors or on farm repairs, and come to TIG when the appearance of the weld matters.

MIG for speed and easy learning

Wire feeds continuously, so you concentrate on the puddle. Best on clean steel from about one millimetre upwards.

Stick for rust, wind and thick steel

No gas bottle, so it works outdoors where a breeze blows shielding gas away. Tolerates surfaces that MIG will not.

TIG for control and other metals

The choice for aluminium, stainless and anything visible. Slow, precise and the hardest to pick up.

Gasless MIG is a compromise, not a shortcut

Flux cored wire without a bottle is convenient and it spatters, smokes and leaves slag to chip. Fine on structural work, ugly on show work.

Check the duty cycle, not just the amps

Duty cycle is how many minutes in ten it can weld before cooling. A high amp figure with a low duty cycle stops just as you get going.

Match the machine to your power supply

Thick steel needs current, and current needs a supply. A machine that trips your ring main every time is not a machine you own usefully.

The two hazards that cause permanent harm

An arc gives off intense ultraviolet light. Looking at it without a proper filter causes arc eye, which feels like sand under the eyelids for a day or two and does cumulative damage to the retina. It happens in seconds, and it happens to bystanders who glanced over from across the workshop.

The other hazard is the fume. Welding fume is now classed as a carcinogen, and galvanised steel gives off zinc oxide, which causes an illness with genuine flu symptoms. Neither hazard announces itself while you are working.

An auto darkening helmet, correctly set

Set the shade for the current you are running and test it before striking an arc. A helmet that fails to darken is worse than no helmet, because your eyes are already open and pointed at the arc.

Screen the area for everybody else

Anyone in line of sight can get arc eye without ever looking directly at the weld. Screens or curtains are for other people, not for you.

Extract the fume at the source

An extraction arm or a fume hood at the weld, not a fan pushing it around the room. Opening a door does not count as ventilation.

Never weld galvanised steel without extraction

Zinc fume causes metal fume fever, which lands people in bed. Grind the coating back beyond the weld area first.

Cover every inch of skin

The arc burns skin like strong sun, and it burns through a thin shirt. Leather, a proper jacket, and no synthetic clothing anywhere near it.

Move flammables, then check again

Spatter travels much further than people expect and smoulders quietly for an hour. Most workshop fires start after the welder has gone home.

Preparation is most of the weld

A weld is only as good as what it is welding to. Paint, rust, mill scale, oil and galvanising all contaminate the puddle, and contamination shows up as porosity, which means a weld full of small holes that looks fine and is not.

Fit up matters just as much. Metal that does not meet cannot be welded together, only filled, and a filled gap is weak. Cut accurately, clamp tightly, tack first, then weld.

Grind back to bright metal

Both sides, and beyond the weld area rather than just on the line. Clean metal is the single biggest factor in a sound weld.

Fit up before you strike an arc

Gaps make bad welds. A tight joint welds itself almost, and a two millimetre gap becomes a fight.

Tack, then check, then weld

Tacks hold the alignment while you confirm it is square. Welding a long seam first and checking after means starting again.

Expect distortion and plan for it

Heat shrinks metal as it cools, and it pulls the work out of shape. Stitch alternate ends, spread the heat, and clamp more than feels necessary.

Clean the wire brush between materials

A brush used on mild steel then on stainless drags carbon steel into it, and the stainless rusts along the weld. Keep separate brushes.

What to buy first, in order

Stage one: protection

An auto darkening helmet, a leather jacket or sleeves, welding gauntlets, safety boots, safety glasses for grinding, an FFP3 mask, ear defenders and a fire extinguisher. Buy this before the machine.

Stage two: the machine and consumables

The welder itself, gas if the process needs it, the right wire or rods, spare contact tips and nozzles, and an earth clamp that actually grips.

Stage three: preparation and holding

An angle grinder with cutting and grinding discs, a wire brush, a chipping hammer, a set of welding clamps, a magnetic square and a steel rule and scriber.

Stage four: refinement

A bandsaw or chop saw for square cuts, a bench vice, a positioner or rotating table, a flap disc set and a fume extractor if your space is enclosed.

Mistakes that ruin a weld

Welding over paint, rust or galvanising

Contamination puts holes through the weld. It looks acceptable on the surface and fails under load.

Wrong shade, or a helmet not tested first

Too light damages your eyes, too dark and you cannot see the puddle, so you weld blind and wander off the joint.

Travelling too fast

The most common beginner fault. It gives a thin, high, ropey bead that has not fused into the parent metal at all.

No gas, or gas blown away

A closed valve or a breeze gives a spitting arc and a porous weld. Outdoors, MIG needs a screen or you need stick instead.

A poor earth clamp

Half of all mysterious arc problems. Clamp to clean bare metal on the workpiece, never to a painted bench or through a hinge.

Ignoring distortion until the end

By the time the frame is welded, it is out of square permanently. Measure the diagonals as you tack, not afterwards.

Grinding the weld away to make it look neat

The weld is the strength. Dressing the surface is fine, and grinding into the parent metal removes what you just built.

Looking after welding equipment

Keep stick electrodes dry

The flux absorbs moisture and then the weld is porous. A sealed tub, and an oven for low hydrogen rods if you use them.

Change contact tips as consumables

A worn tip gives an erratic feed and a wandering arc. They cost very little, and people keep them far too long.

Anti spatter spray on the nozzle

Spatter builds up inside a MIG nozzle and disrupts the gas shield. A quick spray keeps it clear and saves the nozzle.

Blow the machine out regularly

Grinding dust is conductive and settles inside the case. Compressed air with the machine unplugged, every few months.

Store gas bottles upright and secured

Chained upright, valve protected, never left free standing. A falling bottle with a snapped valve is a serious projectile.

Replace the helmet lens covers

The clear cover takes the spatter so the filter does not. Pennies each, and a pitted cover makes you think your eyes are going.

Frequently asked questions

What welding tools do I need to start?

An auto darkening helmet, welding gauntlets, a leather jacket or sleeves, boots and a fire extinguisher first. Then a machine with the right consumables, an angle grinder, a wire brush, a chipping hammer and a set of welding clamps. Protection genuinely comes before the welder.

What is the difference between MIG, TIG and stick welding?

MIG feeds wire automatically and is fastest and easiest to learn on clean steel. Stick uses coated rods, needs no gas bottle and tolerates rust and wind, so it suits outdoor and thick work. TIG gives the most control and handles aluminium and stainless, and takes the longest to learn.

Which welding process should a beginner start with?

MIG, on mild steel from about one millimetre upwards. The wire feeds itself so you can concentrate on watching the puddle, and progress is quick. Add stick if you work outdoors, and come to TIG when the appearance of the weld matters.

What shade should my welding helmet be?

It depends on the current. Roughly shade 10 for low amperage, up to 13 for high current work, and an auto darkening helmet with an adjustable range covers it. Test that it darkens before you strike an arc, every session.

What is arc eye and how quickly does it happen?

Ultraviolet burn to the surface of the eye, which feels like grit under the eyelids and starts hours later. It happens in seconds of exposure, including to bystanders who only glanced across the workshop, which is why screens matter as much as helmets.

Is welding fume actually dangerous?

Yes. Welding fume is classed as a carcinogen, and galvanised steel releases zinc oxide which causes metal fume fever with genuine flu symptoms. Extract at the source rather than relying on an open door, and grind galvanising back before welding it.

Why is my weld full of small holes?

Porosity, and it is almost always contamination or shielding gas. Grind back to bright metal on both sides, check the gas is flowing and the bottle open, and make sure a breeze is not blowing the shield away from the puddle.

Can I weld outside with a MIG welder?

Only with a screen. Wind blows the shielding gas away and the weld becomes porous, and it takes surprisingly little breeze. For outdoor work, stick welding or gasless flux cored wire is the right answer.

Do I need a gas bottle?

For normal MIG and for TIG, yes. Stick welding needs none, and gasless flux cored MIG wire carries its own shielding, which is convenient but spatters more and leaves slag to chip off. It is a genuine trade off rather than a free lunch.

Why does my arc keep cutting out?

Check the earth clamp first, on clean bare metal on the workpiece rather than a painted bench. After that, a worn contact tip, a kinked liner or the duty cycle cutting in as the machine overheats.

What is duty cycle?

How many minutes out of ten the machine can weld before it must cool. A machine rated 180 amps at twenty percent duty cycle welds for two minutes then rests for eight, which matters more than the headline amperage.

Can I weld aluminium with a MIG welder?

With the right setup: aluminium wire, a spool gun or a well set up push pull system, argon rather than a mix, and a different technique. A standard steel MIG setup will feed badly and produce a mess. TIG is the usual home answer.