GET YOUR SET­TINGS RIGHT

Unique Cars - - WORKSHOP BASICS -

PRE­PARE TEST PIECES

Make life easy for your­self by start­ing out on 3-5mm mild steel cut into hand­sized rec­tan­gles. Avoid rusty scrap or re­ally thin metal, or you’ll give up be­fore you start. Clean off any mill scale with a flap disc in an an­gle grinder and de­grease it thor­oughly.

SYNERGIC AD­JUST­MENT

Many mod­ern sets have synergic con­trols. Some can work out the volt­age and wire speed if you tell them the ma­te­rial thick­ness, wire di­am­e­ter and gas type. Oth­ers main­tain a pre­de­ter­mined re­la­tion­ship be­tween volt­age and wire speed.

EARTH CLAMP

A good earth is es­sen­tial for a good weld. If you have a cheap welder with a jumper lead-style clamp, it’s worth in­vest­ing in a more ro­bust type. Place the clamp as near to the weld as pos­si­ble. Cop­per strands will in­crease the con­tact area.

FIND A BA­SIC SET­TING

Be­gin tun­ing-in your set with the volt­age too low and the wire speed too high. It’ll look and sound nasty, but it’s a start. As you get used to your set, you’ll get bet­ter at pre­dict­ing set­tings. Some sets come with handy charts to cal­cu­late ba­sic set­tings.

VOLT­AGE AND WIRE SPEED

All sets are dif­fer­ent, but at the heart there will be two main con­trols: volt­age and wire speed. A good weld re­lies on their cor­rect re­la­tion­ship. Some sets have knobs; oth­ers but­tons. The con­trols are rarely marked in ac­tual volts or me­tres/min.

TRIAL WELD

Turn on the set, gas and shield. Hold the torch in one hand with your fore­fin­ger on the trig­ger. Steady the torch with your other hand. Hold the torch’s con­tact tip 9-12mm from the sur­face at the an­gle shown. Pull the trig­ger for a few sec­onds.

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