Furick Fupa 12 / 13 Parts FAQs
Gas lens diffusers, cups, O-rings and fitting tools for a gas lens TIG torch, and how to pick the right ones.
Is there a hazard when grinding thoriated tungsten, and what should I use instead?
Thoriated electrodes are slightly radioactive, but the overall risk is generally considered low. The main concern is grinding, which releases fine dust that should not be breathed in. Use a dedicated grinder with local dust extraction, wear a suitable filter mask and eye protection as your risk assessment directs, and collect the dust safely, for example sealed in a bag.
Lanthanated, ceriated and zirconiated electrodes are generally acceptable alternatives with lower risk. If you stay with thoriated electrodes, be able to justify the choice. Store them in a closed, labelled box and check the electrode maker's safety data sheet.
What is a gas lens diffuser and how does it differ from a standard collet body?
A gas lens diffuser fits behind the cup and passes the shielding gas through layers of fine mesh, so it leaves as a smoother, less turbulent column. A standard collet body usually has small side holes that give a less controlled flow.
The diffuser is not the same part as the collet that grips the tungsten. It is normally sized for a given tungsten diameter, so check the marking on the old part, the torch manual or the data plate before ordering. A diffuser also needs a cup designed to fit it.
Does a gas lens let me use a longer tungsten stick-out?
Usually, yes. Smoother gas flow lets the shielding column reach further, so the tungsten can often extend further beyond the cup while still being covered. This helps on awkward joints and corners where a short stick-out will not reach.
The difference may be small with a very short stick-out. A longer stick-out also makes the tungsten run hotter and easier to touch to the work, so keep it as short as the joint allows. Published rules of thumb for the maximum vary, from about half the cup bore to about the full bore, so follow the torch maker's guidance.
What is the difference between ceramic and clear glass TIG cups?
Ceramic (alumina) cups are opaque and are the usual choice for general use. Clear glass cups let you see the tungsten and the arc, which can help when welding into corners or lining up a joint. The visibility advantage shrinks with larger cups and longer stick-out.
Glass is generally more fragile, and many suppliers advise against touching the cup to the work, so check the maker's guidance. Both types can crack from knocks, heat or rapid temperature change. Either way, the cup must be the style made to fit your diffuser and torch head, so match it to the old one.