Mig gas bottle.

[Musht]

Hazards a lot higher with oxy acetelyne bottles around.

Mig gas is just inert compressed gas, argon mixed with CO2 , don`t be tempted to try pub gas cylinders , its CO2 only and spits like a damp bonfire. Argoshield/Coogar argon mixes are easier to use.

2 choices fo rcylinder rental, BOC or Air Products, Air Products are in Randolph Ind in Kirkcaldy, used to be friendlier than BOC, you end up with at least a 12month contract on the bottle which is generally more expensive than getting it refilled. Also need a regulator to fit the bottle.

Or just use the disposable little bottles from Machine Mart for a one off project

.CO2 / Argon Mix Gas Cylinder (110Ltr) - Machine Mart

Though the BOC deal Martin pointed out looks very competitive.

Gasless mig costs an absolute fortune in wire but is good for outdoor repairs where gas shielding can get blown away,