Buying a Used GTT Torch: A Model-Specific Checklist

Short answer: A used Glass Torch Technologies torch is worth buying when you can prove three things: which GTT model and version it actually is, that the valves, jets, studs and hose adapters are intact, and that it lights quietly and burns an even flame across its range. Jet count alone does not identify a GTT torch, because several models share one, so confirm the model against GTT’s own product pages before you talk price. Every GTT torch is a surface-mix design, so a torch that bangs every time it lights deserves a question before money changes hands. GTT services its own torches at the factory, which is the safety net that makes a tired but sound used GTT a reasonable buy.

This is the GTT-specific companion to our used lampworking torch buying guide, which covers the general inspection, pricing, and hydrogen-tip questions for any maker. Read that first; this page only adds what is particular to GTT hardware. For where each model sits in the line, the model-by-model GTT lineup guide has the detail.

Step one: pin down the exact model and version

GTT’s line is large, and several models share a jet count, so a listing title is a claim to check rather than a fact. Our catalog, built from GTT’s own pages, records these figures for the smaller bench models:

Three pairs collide. The Bobcat and the Lynx both carry seven jets, but the Bobcat is standard surface mix and the Lynx is GTT’s patented Triple Mix, and GTT prices them far apart. The Scorpion and the Cheetah both come to thirteen, arranged differently: the standard Scorpion is a two-stage torch with the 5-jet Cricket as its center fire inside an 8-jet outer fire, while the Cheetah is a single stage with a 3-port center inside a 10-port ring. GTT also sells a Lynx-center Scorpion as a separate product with fifteen jets. The Sidewinder and the Phantom both reach twenty-two, and the Sidewinder itself can carry either a standard Bobcat center or a Triple Mix Lynx center.

So ask the seller for a clear, square-on photo of the torch face, a photo of the valve end, and the original paperwork if it survives. Match the face pattern and the number of valves to GTT’s current product page for the model named. GTT’s own Lynx instruction sheet, for example, describes three valves: red for fuel, green for the main outer oxygen, and blue for the secondary inner oxygen that sharpens the flame (GTT Lynx instructions, PDF). A torch sold as a Lynx should match that description. If the photos and the product page disagree, the listing is wrong about something, and you want to know what before you pay.

Two more version questions matter. Is it a bench torch or a hand torch? (Our GTT hand torch guide lists every hand version GTT sells, with its switch option and new price.) GTT sells the Sidewinder as a hand torch or as 2- and 4-stud bench versions, sells a separate hand-torch Delta Elite, and offers the Phantom as a hand torch with a thumb switch for the outer fire. And does it have the compressed air option? GTT offers compressed air on several models and also sells a retrofit, but its own page says some hand-built torches may not qualify and that GTT inspects each torch before agreeing to the upgrade (GTT compressed air retrofit). A listing that promises compressed air should come with the hardware to show for it.

The studs and the hose adapters

GTT bench torches connect through studs on a manifold, and the stud count is part of the model’s identity. GTT offers the Scorpion in 2-stud and 4-stud versions, and our catalog notes that the 4-stud version is what allows a foot pedal on the outer fire and split oxygen sources. Count the studs, confirm the count matches the version being sold, and plan your supply side around it: a 4-stud torch wants four supply connections or a deliberate plan to combine them.

On the Phantom, GTT’s page describes the Standard and Snub Nose Phantom as coming with 1 foot of 3/16 inch hose and adapters with filter screens on each stud, stepping up to standard 1/4 inch ID grade T hose that slides over a barb and is clamped (GTT Phantom). Those adapters are worth a close look on a used torch, because GTT’s instruction sheet is blunt about them: never remove adapters or any component with a filter screen, since removing the screen can let foreign material into the torch, damage the valve seats, and clog internal components. The same sheet says to use hose clamps or other approved connectors on the adapters and to fix any leak immediately.

On the bench, check each barb for cracks, flattening, or signs it was forced. Ask whether the adapters are the ones the torch shipped with. A torch whose adapters were swapped for hardware-store fittings, screens and all, is a torch whose internals may have taken debris, and that is a question for a factory evaluation, not for a guess.

Valves, jets, and the face

Valves. Turn every valve through its full travel. You want smooth motion and a clean shutoff. GTT publishes its own “Valve Cap Separation and Servicing” guide, in PDF and video, on its FAQ page (GTT’s FAQ page), which tells you two things: valve service is a documented procedure, and it is one to follow exactly or hand back to GTT. A valve that is stiff from sitting is normal. One that grinds, will not shut off, or leaks at the valve body is a service item.

Jets and ports. Look straight into the face under good light and count. Every jet on a stage should be open and round. A port that has been reamed oversize by the wrong cleaning wire cannot be put back, which is why GTT ships its own cleaning wires or a cleaning kit with its bench torches; ask whether they come with the torch. Light carbon is common; GTT’s Lynx sheet notes that running a short flame without some of the blue valve open can build carbon in the injectors, so a sooty torch usually means a tuning habit, not a defect. Our GTT cleaning and mounting guide collects what GTT’s own sheets say about the wire, the face brush and carbon, and the general torch maintenance guide covers other makers.

The body and nose. GTT’s instruction sheet warns against striking the torch with glass or other hard objects, because dents and damage can occur, and against exposing it to excessive heat from kilns, ovens, or hand torches. Look for dents at the nose and around the face, and ask where the torch sat in the studio. Face discoloration by itself is usually cosmetic.

The live test, and what a bang means

Light it, or insist on a video of it lighting, running through its range, and shutting down. On a Lynx, GTT’s sheet gives the sequence: fuel first to a yellow flame, then the green outer oxygen until the flame turns blue, and shutdown in the reverse order, blue, then green, then red.

Watch for two things. First, glowing orifices. GTT’s Lynx sheet explains that if the green outer oxygen is set too low the burner jet orifices will glow orange and orange streaks can appear in the blue flame, and that opening the green valve a little should stop it. On a test, glow that clears when you add outer oxygen is a setting. Glow that will not clear, or one jet that burns visibly different from its neighbors after cleaning, is a reason for a factory evaluation.

Second, the sound at light-up. GTT describes all of its torches as surface mix, mixing fuel and oxygen at the surface of the torch rather than internally (GTT flashback arrestors). Bethlehem’s used-torch guidance, written about torches generally, notes that a loud bang on light-up can mean a torch is premixing internally, by design or because something is wrong (Bethlehem Burners). For a GTT, it is not the design. A torch that bangs every time it lights should go back to GTT for a look before you rely on it, and the price should reflect that.

If the torch comes as part of a whole setup, ask how it was plumbed. GTT’s instruction sheet warns never to put a premix torch on the same supply hose as other torches, because flashback can occur and damage the other torches, and requires flashback arrestors on the premix torch’s hoses before the connection to the main supply. A GTT that shared a line with an unprotected premix torch is worth asking about specifically. For how arrestors behave on low-pressure and concentrator supplies, where GTT’s guidance differs from the common advice, see flashback arrestors explained.

What GTT says about service and warranty

This is the part that makes GTT a good used buy. GTT offers factory servicing and repair on its Servicing page, and a torch sent in for retrofit evaluation is disassembled and inspected. GTT’s servicing page says all torches come with a one year warranty against factory defects, and its FAQ adds that the warranty does not include damage from improper usage, misuse, or neglect of maintenance (read 2026-10-06). Two cautions for a secondhand buyer: we have not seen GTT state whether that warranty follows the torch to a second owner, and GTT’s own instruction sheet says that removing factory installed components or failing to follow its directions voids the factory warranty. Ask GTT directly, with the model and any serial or paperwork, before you count on coverage.

Editor’s note: service terms, retrofit eligibility, and warranty language are set by GTT and can change. Confirm the current terms with GTT for the specific torch before you buy, and let GTT’s instructions govern pressures and setup rather than any figure from a listing.

Questions to ask the seller

• Which model and version is it, exactly: stud count, bench or hand, and for a Scorpion or Sidewinder, which center fire?
• Do you have the original paperwork, cleaning wire, base, and hose adapters?
• Has it ever been back to GTT, and for what?
• What fuel did it run on, propane or natural gas, and what oxygen supply?
• Has it ever backfired hard, flashed back, or been dropped?
• Was it ever on a shared supply line with a premix torch?
• Can I see it light, run through its range, and shut down, in person or on video?

A seller who can answer most of these is selling a known torch. One who cannot is selling a torch you will be learning about after you own it.

The bottom line

Identify the model from the face and the valves, not the listing, then price it against what GTT charges for the same model new, less anything it needs to go back to GTT for. GTT’s patented mixing design is explained in the Triple Mix technology guide.

Related guides

• Used lampworking torch buying guide
• GTT lineup, model by model
• GTT Triple Mix technology explained
• Torch maintenance and discoloration
• Flashback arrestors explained

Sources

• Glass Torch Technologies, Servicing
• Glass Torch Technologies, Videos and FAQ (Valve Cap Separation and Servicing guide; warranty exclusions)
• Glass Torch Technologies, Instructions for Lynx Torches (PDF), with our archived copy
• Glass Torch Technologies, Flashback Arrestors
• Glass Torch Technologies, Phantom (studs and filter-screen adapters)
• Glass Torch Technologies, Scorpion 2 and 4 stud
• Glass Torch Technologies, Compressed Air Retrofit
• Bethlehem Burners, Buying a Used Torch