How To Use A Cutting Torch
Lighting the torch & setting the flame:
1. Turn on the "gas" tank valve about 1/2 turn (believe me that's plenty)(set the gas at 10-12 PSI).
2. Open the O2 (oxygen) tank valve nearly all the way. (set the O2 cutting pressure to about 40 PSI, via the twist knob at the O2 gauges on the tank).
3. With your striker (lighter) in one hand, crack open the acetylene valve on the torch handle & light it. (red hose).
4. Open the acetylene more till the flame separates from the tip, then back it off till it "re-attaches". (that's the max you can get from the tip you're using).
5. Now open the O2 on the torch handle till the blue flames are short & bright. (green hose).
6. Then push on the long high pressure valve on the handle & re-adjust the O2 valve on the handle till the blue flames are clear and bright.
7. You're THERE! Check to see that all the holes in the tip end are allowing full flow. If not, shut it off and clean the tips.
To shut the torch off, close the "gas" valve on the torch handle, then the O2 valve. Then I usually crack the high pressure valve (on the handle) to blow out any gas left. Now you can have full use of your torch, & can see "what it can do". You can cut MANY sizes & shapes of material:
Using the cutting torch:
1. Look around to see where your sparks will be going & protect stuff or move it, if needed.
2. See that the piece you cut off has a safe place to drop. (If you catch it you will want to put it down right away).
3. Now, put the tip of the blue flames on an edge of the material and let it get red hot (or start sparking).
4. Then push the cutting valve and slowly start moving in the direction you want to cut.
5. The thickness of the piece will determine how fast you move. But keep moving fast enough so that the sparks are flying at least straight down, or actually angled slightly ahead of the tip.
6. If you go too slow, the molten metal won't clear out & will tend to still hold the pieces together at the end of the cut.
7. Going too fast will cause the sparks to lag behind the cutting tip, & not cut through good enough.
8. Note that I tend to very slightly angle the flame & tip in the direction of the cut. For me this helps to pre-heat the metal & keep the sparks angled slightly forward.
Once you've practiced a few times, the cuts will look pretty decent.
1. You will then be able to think more about using various ways to help you steady your hands & use guides.
2. Using 2 hands is a common practice of the pros.
3. Using a heavy bar as a guide is a quick way to help you make a straight cut.
4. Also using clamps on various other straight edges, like angle iron or channel, can help too.
Other torch and cutting tips:
1. For long cuts on plate steel you may need to use a clamp across the beginning of your cut to hold things in place better.
2. I use a torch many times to cut heavy material instead of a band saw, then do some grinding to dress it up.
3. Use a chalk line to mark really long cuts.
4. A regular cutting tip can also be used for heating smaller jobs, just keep away from the cutting valve.
5. When you get better at the "trigger control" of the cutting valve, you can use it to gouge out cracks for better penetration.
6. You will need to get a O2 bottle that is at least 1/2 again as tall as the acetylene bottle because you will be using MUCH more O2 versus gas.
7. On thicker materials you can use your torch to bevel the edges for better penetration (versus grinding).
8. Lots of popping sounds & splatter likely means that your tip is too close to or touching the molten metal (or your tip orifices are plugged, or BOTH).
9. Make sure when you have your tanks off that the gauges read ZERO! (example: if the O2 reads 20 when it's off, when you set the 40 PSI cutting pressure, you only have 20 PSI that you're cutting with! This happened to me).
10. When you need to cut off just the weld of a job, it takes a CAREFUL touch of the cutting valve & you need to watch for where the pieces join each other & try to not cut into the pieces you're trying to save.
When you're cutting with a torch, there can be a fantastic amount of sparks going everywhere! Please be careful to watch out for the other guy as well as yourself!