X3 FastMig 420 Synergic Air Cooled Parts FAQs
How to choose and look after the torch, feed rolls, cables, filter and control accessories for an air cooled synergic MIG system.
When is an air cooled torch enough, and when should I move to water cooling?
An air cooled torch is the simple option: it has no cooler, pump or coolant hoses, so it is lighter on equipment and easy to set up. Heat is its limit. The longer and hotter the weld, the bigger and heavier an air cooled torch has to be, and it can only run at its rating for part of each cycle.
If most of your welding is moderate current in bursts, air cooling usually suits. If you weld at high current for long, continuous periods, compare the duty cycle of the torch with your real working pattern, and consider whether a water cooled system fits better. Follow the manual for your power source.
How do I know when a contact tip needs replacing?
Replace a contact tip when it shows wear, rather than waiting for a set number of hours. The most reliable sign is a bore that is no longer round: wire movement at high temperature stretches the hole into an oval, which upsets feeding and current transfer. Erratic feeding, an unstable arc and more frequent burnback are other signs.
Fit a tip that matches the wire diameter, because undersized wire in an oversized tip causes poor current transfer and early wear. Seat the tip firmly, as a loose tip overheats, and keep to the recess the torch manual gives. Do not file the bore to extend its life.
When should I replace a torch liner, and what mistakes shorten its life?
A liner guides the wire from the feeder to the tip. Replace it if it is kinked, clogged with debris, worn, the wrong size for the wire, or if the wire will not pull through by hand with the roll pressure released. Steel liners suit steel wire, while plastic type liners are normally used for soft wire such as aluminium.
A liner cut too short is a common cause of early failure, so trim it as the torch instructions say, remove burrs at both ends and make sure it seats properly at the power pin and tip. Tight bends in the torch cable and too much feed roll pressure also speed up wear. Never run a torch without a liner.
What does the interconnection cable between the power source and the wire feeder carry?
On a separate feeder system, the interconnection cable links the power source to the feeder. Depending on the system it carries the welding current cable, the shielding gas hose and a control cable, and some versions add a voltage sensing lead. Water cooled versions also carry coolant hoses, but an air cooled system does not need these.
Cables differ in length and in the size of the current conductor, so choose one that matches your system and the current you use. Strain relief at each end takes the mechanical load, so check it is in good condition. A cable for another system may not fit the connectors or carry the right signals.