Glass Torch Technologies (GTT) Torches

GTT torches are a fixture of the borosilicate and production lampworking world, and the line is broad enough that a maker can step up from a compact starter to a large multi-stage burner without changing makers. From the Lynx up, every step keeps the same Triple Mix design, which matters when you are investing years of muscle memory at the bench, and it is a large part of why working boro artists so often compare flames and troubleshoot in GTT terms.

GTT is known for its patented Triple Mix technology, a surface-mix design that the company says produces a wider, more controllable flame. Triple Mix starts at the Lynx and runs up the line; the entry Bobcat and Cricket are standard surface-mix burners without it. A separate compressed-air option called 4-Way Mix is offered from the Phantom up. In a surface-mix torch the fuel and oxygen meet at the face rather than inside the body, which keeps the mixing chamber cooler and gives the burner a characteristically clean, penetrating flame.

The practical payoff is a flame that drives heat into the center of thick glass instead of just washing the surface. That penetrating quality is why GTT torches are favored for solid boro and heavier functional work, where you need the core of the glass to move, not just the skin.

Because mixing happens at the face, surface-mix burners are also calmer at startup and less prone to the backfire 'pop' that can come with internally premixed designs. The compressed-air option lets a maker push output further without scaling oxygen to match, which matters once oxygen supply becomes the real constraint on how hard you can run.

The line starts with four single stage bench burners. The Cricket is the most economical of them, a 5 jet standard surface mix torch designed to get the best out of a small 5 LPM oxygen concentrator, and it is aimed at soft glass beadwork and first classes. The Bobcat adds two jets and a much wider flame envelope while staying standard surface mix: GTT says it runs well on a 5 LPM concentrator, is optimal on 8 LPM, and does extremely well on 10 LPM or tanked oxygen, which is why it is the usual first serious torch for someone heading toward boro. The Lynx, at $525, is where the patented Triple Mix begins, and its 7 jet face is the pinpoint detail flame the rest of the line gets measured against. The Cheetah closes out the singles with 13 ports in total, a 3 port center fire inside a 10 port outer ring, and it puts a lot of heat into a small torch with a broader flame than the Lynx.

Five two stage bench torches fill the middle. The Scorpion is the least expensive of them at $945: the standard version puts the 5 jet Cricket at the center of an 8 jet outer fire, 13 jets in all, and GTT sells a Lynx center version separately at 15 jets, which is the configuration the $945 listing covers. The Sidewinder is a 22 jet torch built around a 7 jet center fire that can be specified either as a standard mix Bobcat face or as a Triple Mix Lynx face, and GTT sells it as a hand torch with an on/off switch in the handle and as 2 and 4 stud bench versions at the same list price. The Phantom sets a Lynx style center inside a 15 jet outer ring for pipes, functional work and medium boro, and GTT also offers it as a hand torch with a thumb switch for the outer flame. The Mirage adds a second ring for 40 jets and moves into large boro and production work. The Delta Elite tops the group at 57 jets, a 7 jet Lynx center plus 50 outer jets in three rings, with the standard four stud bench model listed at $2,575 and the hand torch version priced separately.

Above them sit the multi stage production burners, all Triple Mix and all three stage except the Quadzilla. The Kobuki carries 49 jets, a 7 jet Lynx center, a 15 jet Phantom middle and a 27 jet outer ring, and GTT says it reproduces the Lynx, Phantom, Mirage and Delta Elite flames plus a wider one of its own. The Ninja and the Samurai both total 72 jets and both list at $4,000, and they differ in how those jets are arranged: the Ninja takes a Phantom middle and a 50 jet outer, the Samurai a Mirage middle and a 32 jet outer. The Delta Mag runs 88 jets, the Cobra 130 and the Viper 200, which spans everything from a Lynx pinpoint to a furnace size flame. At the top, the four stage Quadzilla is custom built to order rather than stocked, so its jet count varies with the configuration and GTT publishes no list price for it. The compressed air 4-Way Mix option is mostly a feature of this end of the line: our catalog records a compressed air configuration for the Kobuki, Ninja, Samurai, Delta Mag, Cobra, Viper and Quadzilla, and for the Phantom and Mirage below them, and the point of it is extra output without scaling the oxygen supply to match.

GTT torches reward intermediate and advanced makers working primarily in borosilicate, and especially anyone heading toward production. If you do detail and pinpoint work, the Lynx-class flame is hard to beat; if you build thick functional pieces, the Delta-class and multi-stage torches give you the heat base to do it without fighting your torch.

Beginners are not shut out. The Cricket and Bobcat are standard surface-mix entry points, and the Lynx and Cheetah are the smallest torches in the Triple Mix line, so a maker can start small and step up without leaving GTT. The Bobcat in particular is a smart first 'real' torch for someone on a single concentrator who wants to grow into boro. Soft-glass artists are served too, though GTT's center of gravity is clearly the boro and production world.

The hand-torch versions answer a more specific need. If you do lathe work, large assembly, or off-mandrel sculpting, the hand-torch versions of the Delta Elite, Sidewinder, and Phantom let you bring the GTT flame to the work rather than the work to the bench.

Two numbers decide whether a GTT torch fits your shop, and for GTT's smallest models pressure is the friendlier of the two. GTT's smallest torches run on fuel pressure as low as 1/4 psi, which is inside what an ordinary household natural gas line delivers: GTT's own flow rate chart starts the Cricket, Bobcat, Scorpion and Sidewinder at that floor, and those four will often run on house gas with no booster in the way. GTT describes the Cricket as running as low as 1/4 psi fuel and 3 psi oxygen, while the flow rate chart lists 1/4 to 5 psi fuel and 5 to 10 psi oxygen for it at the largest usable flame. The rest of the line asks for more at the largest usable flame on propane: the same chart lists 5 to 8 psi of fuel for the Lynx and Cheetah, 10 psi for the Phantom, Mirage, Delta Elite and Kobuki, and 20 psi for the Delta Mag, Cobra and Viper. Whether one of those gives its full flame on a house line is a question to settle with GTT and your gas installer, and a booster is the likely answer. None of that is a promise about your own bench: pipe size, run length and whatever else is on the meter all change what actually reaches the torch, and the manual for your model is the figure that governs.

Oxygen is the running cost, and on this site it is an estimate rather than a spec. The figures in the table above come from GTT's own flow rate chart at the largest usable flame on propane, so they are ceilings rather than what you will draw at a working flame, and GTT puts natural gas consumption at roughly 2.5 times the propane figure. For scale, the Cricket estimate is about 5.5 LPM, the Bobcat about 8.5, the Lynx about 9.5, the Phantom about 16.5, the Delta Elite about 30 and the Cobra about 65. GTT does not publish a flow figure for every model, so a few of the largest burners carry no estimate at all.

Flashback protection is where copying a generic rule does the most damage. Fit the flashback protection your torch and your gas supply actually call for, and take that from the maker rather than from a forum. GTT is specific about it: the company says its flashback arrestors need roughly 5 to 7 psi to open, so they do not belong on the output of an oxygen concentrator, where they may fail to open and will severely restrict flow. For a concentrator setup GTT's instruction is an arrestor at the fuel source, with a flame arrestor as the low pressure device. Nothing here replaces your torch manual and GTT's current instructions, which take precedence, so confirm the pressures and the protection your model needs with GTT before you buy.

GTT torches are a premium purchase, and the larger production burners in particular represent a serious investment in both the torch and the oxygen to feed them. Surface-mix burners at the high end can be thirsty, so plan your oxygen supply around the model you actually want; a Mirage, Delta Mag, or Kobuki will outrun a small concentrator setup quickly.

Lead times and availability can vary, and configuring the right stage count, mount, center fire, and air-injection options is worth a conversation with GTT before you buy. The buying process rewards patience and a clear idea of which model actually matches your work.

Jet counts and stage layouts are usually well documented by GTT. Oxygen figures in this catalog may be converted from GTT's CFH flow table, so they are reference values tied to stated test conditions, not universal operating recommendations. Prices and configurations should be checked on the specific current product page.