Cutting Torch Tips and Tricks

By Simon Graham | Blow Torch

Cutting Torch Tips and Tricks

All trades have techniques and skills involved that have been developed and perfected over the years, and welding metal is certainly no exceptions. Use these helpful cutting torch tips and tricks to increase your ability in cutting steel safer and more effectively.

Preparation and Safety

1. The right tools are essential to learning cutting torch basics. Along with your torch, you should also gather the following equipment.

Fire extinguisher. Let’s face it you are burning metal at extremely high temperatures, be prepared for a fire.

Marking and measuring tools, including rulers, square and a soapstone marker.

Leather-soled work boots will help protect against dropped slag burning through your shoes. These should be laced boots since slip-on shoes often have openings at the top ripe for slag to drip directly onto your foot. Avoid rubber soled boots entirely.

Fire resistant clothing is recommended but avoiding flammable synthetic clothes is a must. They will burn very quickly if they catch on fire. Wear well-fitting cotton clothes with no frays or torn edges to avoid any piece catching a stray spark.

Use a striker to light the torch, as matches and lighters are dangerous. Strikers are specifically designed for lighting torches which reduces the chance of injury.

Blow Torch Tutorials and Lesson

Safety comes first.

2. Work at a comfortable height over a steel table on supports. Stability is crucial to these cutting torch tips and tricks and helps you produce clean cuts. The table will help you brace yourself and steady the torch while cutting. Flammable surfaces should never be used along with any surface that has been exposed to flammable materials. Be careful around materials that have metallic oxide coatings as they produce toxic fumes when heated.

3. Prepare your project by pre-marking the cuts. Accuracy is key to mastering these cutting torch tips and tricks, which is why marking your materials is helpful in this process. Soapstone markers work well as it will not burn away when heated. Permanent marker can work but tends to melt off the metal ahead of the torch. One great way to ensure a clean cut is to outline your markings with divots, which will be easy to see through the sparks and shaded goggles.

4. Put on your gloves before you light the torch. Check your surrounding again for flammable materials or stray objects that need to be cleared away.

5. When opening the valve, stand to the side of the regulator. Should the regulator fail, as unlikely as it is, it will typically fail in a way that forces the gas toward the regulator bonnet and pressure knob. By moving your body to the side, you will reduce the risks of serious injury.

6. Perform leak tests by saturating the tightened metal to metal connections with leak test fluid. Watch for growing bubbles, and only used approved leak test solutions.

7. The right sized tip is needed for the best quality cut. Tip charts are helpful to find the best tip size for the metal thickness you have and for your cutting torch.

8. If you experience any issue with lighting the torch, you can make it easier by “trapping” the gas against a plate at a 45-degree angle. Also, starting the oxygen before the flame is hot enough can extinguish the flame, so be sure to introduce preheat oxygen slowly.

9. The longer or narrower the hose is, the more the gas pressure will drop by when it reaches the tip. You can calculate this pressure drop using calculation or charts.

Cutting Techniques

10. Always support your cutting hand with your free hand for extra stability. This will help keep your cuts clean and protects you from getting fatigued too quickly. These cutting torch tips and tricks are useless if you are not able to hold the torch at a steady height and angle.

11. Use the tip of the inner flame to heat the surface of the metal you are cutting. The steel needs to be heated to the point of creating a molten pool in your cutting location. Thicker metal will take longer to form this pool and get red hot, so keep the flame steady at about 3/8” from the metal’s surface, concentrating the heat in the desired location.

12. Slowly release the oxygen jet by pushing the cutting valve handle slowly down, which should ignite the molten steel. Ignition has started if there is a violent reaction, but if the metal is not hot enough to ignite, release the oxygen handle and continue heating the steel.

13. When you are piercing a piece of steel, a great addition to our cutting torch tips and tricks is to spiral out from the center of the cut. Work from the center outward toward your cutting path to make sure the cut is clean and the right size.

14. The torch should be at the right height so that the inner acetylene flame is just off the cutting surface. Other fuels have different recommended torch heights.

15. Move the torch slowly along your planned cuts when the flame is cutting through steel. You can adjust your speed by how fast you are seeing the sparks and molten slag are being blown back from your cut. If this flow seems to slow, slow your cutting speed to make sure you cut through the steel fully. It’s always better to cut too slowly than too rapidly.

16. Continue cutting with the torch until you have completely severed or parted the metal. Steel is too hard to finish with an anvil and chisel, so you may as well finish the project with flame!

17. The last of our cutting torch tips and tricks cutting techniques is to use the roll in, roll out method for thicker metal. Roll the torch into the edge of your metal, slowing turning it straight. Roll the torch outward at the end of your cut to make a clean sever.

17. The last of our cutting torch tips and tricks cutting techniques is to use the roll in, roll out method for thicker metal. Roll the torch into the edge of your metal, slowing turning it straight. Roll the torch outward at the end of your cut to make a clean sever.

Finishing Up

18. Use water to cool your steel after cutting, or cool naturally if you have time. Remember that pouring or dipping super hot metal in water will create a cloud of hot steam, so be careful while cooling. Water cooling affects quench and temper type steels, so only use this method for mild steel.

19. Chip or grind the slag from the cut for a precise and clean fit.

20. Shut off the torch oxygen valve first, then close the fuel valve. This will check both valves for leaks every time you shut off the torch. Snaps or pops indicate leaks in the oxygen valve and a tiny flame at the tip will specify a fuel gas leak.

 Keep these cutting torch tips and tricks handy whenever you are working with metal to keep your work safe, clean, and precise!

Credits for the amazing artwork in this article:
1. "Using a blowtorch", by Sgt. Mark F.

Leave a Comment:

Leave a Comment: