O/A cutting

By the hat Date 07-25-2004 23:20

Make sure that you match the tip size to the thickness that you want cut and that the gas pressures for your torch are correct.You can find them in the book that came with your torch.Ask your dealer for a copy if you dont have it .The popping could be caused by a dirty tip ,dirty or rusty metal,or the incorrect pressure settings. HTH

By Northweldor (***)

Date 07-26-2004 11:10

In addition to what has already been mentioned, popping (backfire) can also be caused by a hot, loose, or damaged tip. I would find the cause since backfires on a cutting torch are more likely to lead to a flashback, damaging the equipment and, possibly, you! (because of the highly unequal pressures).

Welding-up is probably due to travelling too slow, using too much preheat, or too little torch inclination, on sheet-metal.

By swnorris (****)

Date 07-26-2004 11:30

Hi All,

I agree with the other posts as to what your problems may be, and will add that the popping could also be caused by using the wrong style of tip. Some tips manufactured by a company other than the torch manufacturer will fit other torches, but will pop. As for the thin stuff, such as 1/8" thick, I use a 000 tip, with the oxygen set on about 20 psi, and the acetylene set on about 3 psi, which will result in a long, quiet flame. Also, on thin material, tilting the tip towards your cut line as you cut helps too. Generally speaking, the thinner the material, the faster the travel speed. A lot of people more or less melt the steel rather than cut it because they tend to crank up the gas. A torch doesn't have to sound like a jet engine. If you find a chart, have a steady hand, and follow the oxygen and gas settings, you can get good results with minimal slag that can very easily be scraped off. Just like welding, there's more to it than just firing it up and going at it. Rather than a helper coming behind them and grinding, I have my guys grind their own cuts. Pretty soon, I see them looking at the charts posted around the shop and their cuts improve dramatically.

By jwright650 (*****)

Date 07-26-2004 18:28

Hi Scott,
Our guys grind their own cuts too. Most of them prefer to grind their own cuts. The better they get at cutting, the less they have to ride that ole' Wildcat!
John Wright

By Lawrence (*****)

Date 07-26-2004 22:56

More tips to add to the already good stuff

Here is a link to a nice multi vendor tip chart.
(Different vendors have different oxy/fuel requirements)
http://www.hoopersupply.com/cut.htm

Safety:
About the backfires and flashbacks, remember this; Flashbacks and backfires are most often caused by fuel gas starvation. When welders use the same tip for cutting 1/2 inch (thick) and Gauge (thin) steels they sometimes turn the fuel gas too low to cut the thinner material. Insufficient fuel gas presure allows the flame to retreat back into the torch (this is also true for oxy-fule welding tips and rosebuds (multi-flame heating torches.) Lots of talk goes on about overheating cutting tips by getting them too close to the work. The fact of the matter is that when the proper fuel gas pressures are used, tips will almost never overheat. With cutting tips; Keep the little blue jets just off the metal, if they touch than your too close.

Taking the time to put on a smaller tip for thin materials has the double advantage of increasing safety and producing a smaller kerf (the bite the torch takes out of the metal) which can make for more precice cutting accuracy.

By billvanderhoof (****)

Date 07-27-2004 07:15

... and the right size tip saves fuel and oxygen too.
Bill

By pgeweldor (*)

Date 07-27-2004 10:51

Hi everybody, I just wanted to mention something that I think is important, and might be a big help to everyone. Make sure that the flame you are cutting with is Neutral and not oxidizing also, along with the other excellent advice. Good Luck, Hope it helps. Paul