TOOLS How to: Setup and use The Little Torch

The Smith Little Torch Kit 23-1014

I had to write this tute because neither the kit I purchased nor their website adequately explain how to use their system, at least to a beginner.

The Lacy West Supplies made a much better effort to educate Little Torch users.

I consider this tutorial a visual supplement to the Lacy West instructions, inspired by their steps. My tutorial focuses only on the kit that uses the disposable tanks (23-1014).

I would highly recommend reviewing Lacy West Smith Little Torch Instructions and Operations Manual to gain a solid safety perspective. These systems aren't to be taken lightly. Use this system in a well ventilated area, wear the appropriate eye gear, etc., that sort of thing.

For those who are new to these kinds of torch systems:

This system combines two gases to produce a flame from very small tips, so it's good for precision or hard to reach brazing tasks. The flow of the gases is regulated by regulators that sit on the tanks. The particular regulators in this system are preset, so they are designed to be turned all the way on. The gas flow is secondarily controlled by the torch valves on the torch itself. Those can be adjusted to vary the flow and mix of gases.

The Little Torch can be used with several fuels including acetylene, hydrogen, propane, proplyene, MAPP, or natural gas.

The Smith Little Torch Kit 23-1014 - for use with disposable propane or MAPP and oxygen tanks.

It works for most jewelry soldering applications or when portability is needed. Best for intermittent use and repair work, or in areas where larger refillable cylinders are not allowed. Works with single flame tips, sizes 3-7. Will not work with multi-flame tips. With size 5 tip, an LP tank will last over 14 hours. An oxygen tank will last from 15-60 minutes of operation. Note: MAPP® gas will use up to 35% less oxygen.

Disposable gas cylinders

This "Little Torch" uses disposable cylinders found in most hardware, retail, or welding outlets. I use oxygen tank (red) and either a propane (blue) or MAPP (yellow) tank. I get mine at Home Depot or Orchard Supply Hardware, since they're close to me.

But I haven't figured out yet how I can dispose of the tanks, once there's not enough gas left for them to be used with a torch. They may be called disposable, but my local waste management company won't accept them nor will most other facilities. They're not that easy to dispose.


Disposable oxygen tank, always red, as far as I can tell

Disposable propane tank

Disposable MAPP tank; burns apprx 500 deg hotter and requires less oxygen than propane

Attach hoses to preset regulators Use only the hoses that are supplied by Smith.

The hoses are color coded: green for oxygen, and red for fuel gas. Note, you may think the red hose should connect to the O2 regulator since the regulator attaches to the red O2 tank. But nooooooo!

My kit came with the hoses already attached to the regulators, but yours may not. So you'll need to do it yourself.

  • Attach the red hose to the fuel gas regulator and tighten securely using an 11/16" wrench.
  • Attach the green hose to the oxygen regulator and tighten securely using an 11/16" wrench.


Attach preset regulators to disposable cylinders

Make sure the both black regulators dials are in the "off" position

The green hosed oxygen regulator and oxygen tank threads turn in the opposite direction from the red hosed fuel regulator and fuel tank. So you can only attach the correct regulator to the correct tank.

Pretty brilliant!

O2 gas

Attach the green hosed oxygen preset regulator (identified by the word "OXYGEN" stamped on side of regulator) to the red oxygen cylinder. By hand, turn counter-clockwise and tighten securely.

Fuel gas

Attach the fuel gas preset regulator to the disposable fuel gas cylinder. By hand, turn clockwise and tighten securely.

The Smith Little Torch with disposable tanks.

I like to rest the two tanks in the wire rack set in a small baking tray. The tray keeps the wire rack and the tanks locked in position.


Test for gas leaks

  1. Mix 1 part liquid dish detergent to 4 parts water and stir to create suds.
  2. Pressurize your torch system
    • make sure the green and red torch valves are closed
    • open the black preset oxygen and fuel gas regulators all the way. Because they're preset, you don't have to deal with adjusting the pressure.
  3. Use a paint brush or sponge to dab the sudsy mixture on various connections and fittings like:
    • where the regulators attach to the tanks
    • the check valve
    • where the tip attaches to the torch handle
    • around the torch valves
  4. After you've covered areas like those with the soapy water, look for bubbles still forming on any surface, specifically ones that are growing and popping. If you see some, it's an indication of a gas leak.

Any sign of a leak is dangerous and needs to be corrected immediately. Shut down the system:

  1. Close the oxygen preset regulator
  2. Then close the fuel preset regulator
  3. Remove the torch tip.
  4. Slowly open the green oxygen torch valve until all the pressure is removed, then close the valve.
  5. Slowly open the red fuel torch valve until all the pressure is removed, then close the valve.

Retighten fittings and connectors, then test again. If you still see indications of a leak, shut down your system and contact the vendor or manufacturer. Don't use it until it can pass the test.

Purge the Gases
Before lighting the torch, purging of the system is necessary to reduce the possibility of a mixed gas condition in the system. A mixed gas could cause an explosion. Purge in a well ventilated area.

  1. Make sure the green and red torch valves are closed.
  2. Remove torch tip
  3. Open both black preset regulator valves completely.
  4. Open the green oxygen torch valve completely for 2-3 seconds to purge line.
  5. Close the green oxygen torch valve.
  6. Open the red fuel torch valve completely for 2-3 seconds to purge line.
  7. Close the red fuel torch valve.
  8. Make sure both torch valves are closed.
  9. Replace torch tip. Tighten with a 5/16" wrench (do not over-tighten).

Light the Torch

  • Make sure the green and red torch valves are closed.
  • If they aren't open already, open the black preset oxygen and fuel gas regulators all the way. Because they're preset, you don't have to deal with adjusting the pressure.

  • open the red fuel torch valve approximately 1/8 to 1/4 turn.
  • ignite the torch tip using an approved friction lighter (or holding the tip over an approved Bunsen burner or candle.)
  • the flame will be yellowish and it may be a litte sooty
  • slowly release enough gas so the flame is about 4" long
  • keep the flame in touch with the tip, if it isn't, reduce the gas flow

  • very slowly open the green oxygen torch valve
  • the flame will get a brighter, straighter and tighter

  • slowly increase the fuel gas until the flame forms two visible parts; a bigger outer translucent blue flame and a smaller inner white flame
  • this is considered a neutral flame and the one to achieve for brazing.

You may see the following collection of phrases. It refers to the ratio between the fuel gas with the oxygen gas. Each type looks different and has different uses.

  • reducing flame (less oyxgen)
  • neutralizing flame (hottest, most efficient flame, best balance of fuel and oxygen gases)
  • oxidizing flame (more oxygen)

Note: Safety dictates when the flame dwindles due to a loss of pressure, immediately shut down the system and mark that tank for disposal.


Unlight the torch

  1. Close the green oxygen torch valve.
  2. Then close the red fuel gas torch valve.

Thanks for Michael J. for this correction. He adds:

Backfires can be caused by shutting off the fuel gas first, allowing the flame to burn back in the oxygen rich mixture. The flame cannot burn without oxygen. Oxygen should always be shut off first to keep the soot out.

Shut down the torch

After unlighting the torch, the next step is to shut down the flow of gas between the regulators and the torch and bleed the gases out.

  1. Close the oxygen preset regulator
  2. Then close the fuel preset regulator
  3. Remove the torch tip.
  4. Slowly open the green oxygen torch valve until all the pressure is removed, then close the valve.
  5. Slowly open the red fuel torch valve until all the pressure is removed, then close the valve.
  6. Store securely.


Over the years I've purchased various torches for jewelry; hardware store propane and MAPP (a modified and hotter version of propane), a Smith Little Torch, a Blazer butane, and 3-4 hardware store mini-butane torches.

WRT to the Smith Little Torch, unless the packaging has changed, it comes with practically no instruction. Mine came with a 4-5 cryptic sentences printed on the back. And far, far more instruction is needed for those systems. Proper handling of the Smith, because it uses the combination of O2 and a fuel gas, is a must. But the instructions were no help. I had my Smith Little Torch for a number of years, but felt I couldn't use it safely until I had a good set of instructions.

After using simpler torches for a few years and learning a little about brazing, I finally tackled my Smith this year. That's when I realized it's nearly criminal lack of instruction. I found this on the web, and as comprehensive as those instructions seem, I discovered - the hard way - that they still weren't complete. Plus no pics!

Smith torches have very fine torch tips compared to the other types of torches, which is very useful for precision fine point brazing, but only that. I'd say it was a fairly special-use torch.

The mini butane torches from hardware, kitchen supply, jewelry supply shops, etc. are a nice start for brazing, as long as you don't go thicker than 16 gauge wire. What's also nice about the mini-butanes is I haven't seen them come with the warning that they must be used in well-vented rooms or garages, etc. like propane and MAPP torches. They're small and light and less intimidating than their standard cousins. But they're for small work, short fires. And any gas burning appliance should only be used in a well-vented room. ;-)

The propane and MAPP torches are great general purpose torches. As I mentioned earlier, the MAPP is much hotter. Uses include jewelry, plumbing and certain kitchen tasks. They're not as refined nor as complex as the Smith torch, but they also cost about a tenth of the price. You can get single use tanks (which may be a pain in the butt to dispose of) or refillables. They can be much bigger than the mini torches. Both the standard propane/MAPP and mini butanes are, oddly, about the same price range; $20 - $50.

I'd recommend getting a Blazer and/or a basic propane or MAPP torch and doing lots of reading or taking a lesson on how to use them. If you're adventurous and not afraid of the heat, go for the bigger puppies. If you want to try something a little less intimidating, a little more approachable, try the Blazer or something similar in quality.

I now use all my torches, for different tasks at different times. I have heard, but have no experience with it, torchable PMC isn't as strong as kiln-fired PMC. Something to research.


There's nothing better than having a great tool when you need it.


Last update to this page: 24 Aug 08. Send comments, questions or suggestions to Desiree McCrorey.