Cutting torch?

[Cullen]

Over the weekend I tried my hand at cutting with an oxy acetylene torch. I was cutting some 1/4" plate and it seemed to take me way to long. I could have just used my angle grinder it was so slow going.

I have no idea where to put my settings, I just adjusted it until I had a short blue flame. What do I need to do look or listen to get this to work right.

Thanks

[Mike Sherman]

Set your oxygen at 40 and your acet. at 7. Do not ever let your acetylene get over 15, it will make for a potentially bad day. Light with just your acet. on, adjust until your flame just about jumps off the tip (maybe back it off just a little after it jumps off), turn your oxy. on until you have very clearly defined little blue spikes of flame, push down on the lever, readjust flame so you have the same little blue spikes you had before you pushed the lever. Some people use slightly different settings, it will depend on the size of tip and the torch you have. Use these as starting points. This is about as basic as I can get, let me know how it works.

[morpheus]

You might also make sure that your oxy valve at the base of the torch is wide open. Just set it at wide open and then use the upper valve to adjust the flame. If you don't do it that way you don't get full oxygen when you hit the lever to cut. good luck.

- jack

[Mark Whiddon]

one other thing is to keep your torch just far enough from the metal that the blue flame does not quite touch the metal as you are heating it. Once it gets hot enough to add the O2 with the cutting lever, move accross the metal fast enough to push the molten metal out the bottom of the plate. With 1/4" stuff it should cut way faster than an angle grinder. I usually can cut in the 20" per minute on average some times more sometimes less. If it is rusty it cuts slower.

[rangerod]

Cullen

You definately should be cutting faster than a angle grinder can cut 1/4". This is for after you get the torch cutting properly. If after you make the adjustments and have alot of slag on the bottom side of the cut back off on the fuel as much as possible for the thickness you are needing to cut. Your cut surface should be smooth & little or no slag on the back side of the cut. This will result in very little grinding being required to dress the cut surface.

[ChadRat]

I am guilty of too much slag on the back. Do I turn the gas down on the torch or at the valve?

[cope]

Get the recommended settings for your brand of torch and follow them. Set the regulator screw for the recommended pressure and then fine tune at the torch/ Remember that for cutting you leave the oxy knob wide open on the barrel and adjust with the knob on the cutting head.

[rangerod]

ChadRat

Turn the fuel down on the torch. The regulator settings do not change. I was guilty of using way too much fuel for the longest time then a old timer gave me a scolding for having to take so long to grind the slag off. I didn't mind the scolding because he sat down and showed me what I was doing wrong Its going to be trail & error unless you have someone there to show you. Just keep making adjustments & check the results of the changes

[ChadRat]

I set my regulators to the manufacturer's suggested settings. I turn the oxy wide open. I will try Mike's flame jumping tip.

Too much slag? Get a big 7" grinder

[Roger]

Have Scotty beam you up a copy of Victor's Oxy-Fuel Welding, Cutting & Heating Guide. Your local welding/industrial gas dealer should have it. Has 9 pictures of cut from quality Cut, travel speed too fast, travel speed to slow, cutting O2 pressure too high, cutting cutting O2 pressure to low, too much pre-heat, too little pre-heat, tip too far from plate, tip too close to plate. Better yet above the pictures is detailed chart with discription of vairiables and conditions explaining what you see in pictures. My copy was free.

[Bobby]

you are using an oxy/act cutting torch right no just the welding/brazing torch?

Just curious. it should cut REAL fast compared to a angle grinder

[Roger]

With proper torch tip and flame adjusted right most common newbe problem is cutting too slow. Cutting too slow welds kurf shut with slag. Cutting rate should be so fast that much faster causes you to loose the cut.

[Sberry]

I also am a fanatic about tip size and clean tip. Number 1 or so tip for 1/4th to 1/2 and 20# oxy for 1/4 and 25 for up to 1/2. Just enough to burn thru is what makes a clean cut and more is also wasteful. I do turn up a bit when scrapping, maybe 30# or so. That 40# was just kind of old timers thing I think,, kind of hearsay and lots of guys that use a torch have never really learned the right way. (comment not aimed at anyone here) Lots of trial and error often makes for a poor education. Lots of times in dirty ole factory repairs where here is lots of weld washing and long hose runs the pressure is turned up some too.

[stomper74]

Lots of good info on setting pressures and adjusting torch already posted. After you fire it up on acetylene ,add the oxygen and adjust it until you have the aforementioned little blue spikes on the outer ring (adjust oxygen until white feather disappears), then you can check to see if your tip is clean. Hit the cutting lever, watch your flame and listen. If your flame doesn't extend 6 to 8 inches longer and make a sound like paper ripping, then you are going to have a tuff time getting a clean smooth cut with little to no slag on back side. Even new tips sometimes have to be cleaned to cut right. Check at your welding supplier for a good set of tip cleaners. Cutting rusty metal, getting too close and putting fire out, blowback from starting a cut in the middle of a piece (ie hole in center of plate) will all dirty up a tip and make you want to pull your hair out. Be careful, tip cleaners will break off and plug hole like nobodys business, but used properly will surely help with speed and easy cleanup.