Furick 3 Series TIG Parts FAQs
Cups, collets, gas lens parts and kits for a larger-style TIG torch: how to match them to your torch and tungsten, and how to look after them.
What is the difference between a gas lens and a standard collet body?
A standard collet body holds the collet and passes shielding gas out through a few side holes, which can leave the flow turbulent. A gas lens holds the collet too, but passes the gas through fine mesh screens, giving a smoother, more even column of gas.
That smoother flow lets the tungsten stick out further and suits critical or high-quality welds, but a standard collet body is perfectly adequate for many jobs. A gas lens needs a cup made for it, so do not mix the two styles. Check the torch maker's parts list for the combination your torch uses.
How far can the tungsten stick out of the cup?
Keep the stick-out as short as the joint allows. A common workshop rule of thumb is that the tungsten should not stick out past the cup by more than somewhere between half and the full inside diameter of the cup, but this is a guide, not a standard. A long stick-out is a recognised cause of poor shielding, and the usual fix is to reduce it or fit a larger cup.
A gas lens gives a smoother column of gas, so it tolerates a longer stick-out and helps in corners and tight access. Whatever you choose, check the weld for discolouration or porosity and follow the torch maker's guidance for your set-up.
How do I set the gas flow when I change cup or fit a gas lens?
Use the lowest flow that gives good cover for your joint and conditions, because too high a flow causes turbulence and can draw air into the shield, leading to porosity. A larger cup generally needs more gas to fill it than a small one.
Start from the guidance in the torch and welding power source manuals, then adjust for the material, joint and any draughts. Long gas hoses can cause a surge of gas at arc start, so a suitable pre-flow time helps. Discoloured or porous welds are a sign that coverage is wrong.
How do I match the collet, collet body and tungsten size?
The collet and the collet body or gas lens must suit the diameter of the tungsten electrode. Maker parts lists and kit tables are organised by tungsten size for this reason.
Work from the tungsten you will use. A 2.4 mm electrode, for example, needs a 2.4 mm collet and a matching collet body or gas lens. If you change electrode diameter, change the matching parts too. A worn ordinary split collet can twist or jam, and a wedge-style collet is the maker's suggested answer for short collet life, so ask if one is made for your torch.