Torches stop cutting

Jason1Pa

Member
Ok first off I'm new to using a cutting torch. Back in the summer I finally got a nice set of Victor torches. Just by doing some practicing and a lot of reading I was pretty pleased with how it was cutting. Nice and clean. I actually shocked myself. Today I was working on a project and was cutting 1/4 inch plate of steel. I was cutting along just fine but occasionally it would stop cutting. I'd release the trigger and squeeze it again and all would be good for a while then it would do it again. Any idea what could cause this? The last time I used it it did it a couple times but not as bad as today, I'm running around 3 pounds on the acetylene and about 10 on the oxygen. It worked flawlessly before with this setting. Any higher the cut was real wide and rough and would fuse its self back together behind the flame as I went along.
 
Keep the pinky finger of the stabilizing hand on the material your cutting to help keep the torch stable and move smoothly. When cutting the oxygen actually burns the steel, If your real good you can actually shut off the torch and keep cutting with just the oxygen as long as you keep the puddle. Each time you loose the puddle you have to stop and re-heat the metal to restart your cut.
 
Perhaps if you bought a used set of torches you might not have instructions to go along but generally for cutting the acetylene would be set at 10 lbs. and the oxygen at 30 or 40 psi. You still set the volume of flow according to the thickness of material. For thin cutting you barely hear the flame and with thicker steel to cut, the volume of gas mix gives you more hiss to go with the heat you need.
 
Another thing to consider: If there are six little preheat holes, it is omni directional. If there are four preheat holes, one of them should be directly ahead of the kerf. Gives the maximum preheat.
 
Jason,

I don't know the Model Number of your torch or what size tip you are using.
In a nutshell, Thickness determines Tip size, Tip size determines pressures, as shown in the chart below.

Also, make sure you have a neutral flame on your torch.

Make sure the oxygen needle valve (on the barrel) is OPEN ALL THE WAY.
You adjust your preheat flame using the oxygen valve on the cutting attachment (torch head).




cvphoto1584.jpg


cvphoto1589.png
 
I would bump up the regulators to 5 and 30 and like has been said maybe slow down just a little tip the torch angled slightly ahead of your cut to preheat it
 
Both pressures are too low and I'm betting your tip is too large. Look at the chart Hank posted and you will notice that a numbered tip is way too large. Oxy/fuel cutting is something where bigger certainly isn't better.
 
Some place I read oxygen does the cutting. I never tried this. Some claim that once you start cutting you could turn the gas off and use O2.

Steel mills have BOF furnace. They add O2 to molten steel to make heat by burning off carbon in steel.
 
Yep, the steel is actually burned by hitting the molten puddle with pure O2. In the fab shops that service the oil industry around here, the position and equipment that cuts steel parts for tanks etc, is called the 'burning table' for that reason. The one's I've see in operation use natural gas or propane/butane and O2. and they can do that, feed the cut pure O2 after the puddle is established and feed rate determined.
 
Best thing one could post for newbee usen a cutting torch . I usually run a double o tip in mine for most things and up to a #2 tip when removing and old cutting edge on a bucket . But in most cases you will find #1 -2 tips in peoples torches and for the most part they are running either to hot or to cold or to fast . For me with this old age thing and the witch Dr. potions i am not doing as well with a torch as i once did as the days of the no grind cuts are now gone . One more thing to point out is keeping the tips dressed and clean .
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top