Welding Tips and Tricks

Hi,

I just bought an used acetylene cutting torch kit. I have never tried a heating/cutting torch kit before.

I changed the hose for a Grade-T one and bought two tips, a 0-3GPN and a 1-3GPN cutting tips for propane (two parts).

I also bought two new regulator because the old one where leaking.

I'm not able to set the torch correctly. It's like there is not enough propane flow/pressure or something like that. If I use my rosebud heating tips, I can get it to produce a lot of heat and get sheet metal red hot in a few secondsa. You can ear the torch making the loud wind noise it's suppose to do.

But when I use the cutting head, nothing. As soon as I try to add some ocygene, it stop. I turn the propane knob to the max and it still does nothing.

Here is a short video I made of the Rosebud vs cutting head: https://youtu.be/WdwR1bJIxSo

In the video I am at 15/40 PSI (propane/oxygene).

I am not sure what I am doing wrong. I tried to crank up the propane to 30PSI but it does nothing more than that. Could the cutting head be clogged somewhere? the tips are new so I know they are not clogged. Both tips do the same thing.

Thanks!

I can’t tell you the correct pressures to run for your torch, but I will tell you what I do to adjust my torch since what I do and your videos show differ.

Close all 3 valves on your torch. Crack open the 2 at the bottom, not wide open. Light the fuel. If the flame is billowy, and a bit more oxygen until it stabilizes (your first video did pretty well). Once the flame is stable, open the mixing valve slightly to get “blue tips” about 1/8” long. Keep slightly adjusting until the blue tips are right. Adding oxygen with the lever will then allow you to cut.

From the video, it sounds like your pressures are too high to me. Someone else may have different or better advice on propane specific setup.

I use oxy acetylene so I can't say what the pressure to use. For cutting you open the oxy valve on the bottom wide open then turn on gas , light and adjust the flame to neutral with the upper valve. Now get the metal hot and press the lever and it should cut. You need to get the edge where your starting your cut red hot before trying to cut. Hope this helps. It takes longer to get that edge hot with propane than with acetylene. With oxy-acet the oxygen is set at 35#.

5-10psi is where I would be on the propane. I've never gone higher than 10psi without having issues or needing a really large cutting head. I personally found 7psi propane and 35psi oxygen to be the sweet spot for me with a 1-3 tip for up to 5/16". Also when you go to cut, keep the tip .5" to .75" off the surface, the flame is hotter there. Start at 5psi on the propane and work up 1psi at a time if you need more.

Metal Manipulator wrote:For cutting you open the oxy valve on the bottom wide open then turn on gas , light and adjust the flame to neutral with the upper valve. Now get the metal hot and press the lever and it should cut.

That's how I do it too - base knob open, adjust with the upper knob.

With propane it takes a couple more times turning the gas knob higher though - its a back and forth process.

Open your oxygen valve on the lower part of the handle all the way. When you hit the lever for your cutting stream the rest of the flame should stay the same. If you leave your gas at the range it’s at then you may need to bump up your oxygen to 45psi. Those are also long hoses your likely getting some pressure drop. So check when you do hit the cut lever to see what your oxy pressure is dropping to. If it drops below 30psi then the regulator or tank may not be big enough to supply a head that size.

Thanks guys for all the reply.

After I posted, I tried some more time and took another video to try to show the flame better. I can't seem to get a neutral flame. When I think I get it, the inner flame is like inside the tips.

In this video, The oxy valve is open all the way. I started with a little propane. Lighted the torch, give it a little oxygen via the upper valve and turned the propane knob all the way full.(I then adjusted my camera) and I didn't touch the propane knob for the rest of the video, only the upper mixing knob, trying to get something.

https://youtu.be/KD-jGIIxLPY

I'll try to lower the propane PSI as suggested, but since the flame is already super dim, I think it will be wost.

Adding too much oxygen in my opinion.

Watch this video - his explanation is excellent.

First several minutes are safety and background info.

https://m.youtube.com/watch?v=f2amO0T3vkQ

MinnesotaDave,

This is the video I checked to know how to adjust my setup.

I was at 40 PSI oxygen, like him.

You can see he have way more flow than me when he is ready to heat the metal. He need to talk louder so we can hear him over the hissing sound of the torch.

Mine don't do any sound, the flame is really short, dim and not powerfull like his.

In my last video, at 0:58 I completly shut off oxygen via th emixing upper knob.. At 1:06, the upper mixing knob is around 1/4 turn open. A little more than that and the flame pop and the torch stop.

When you first light up give it enough gas to lift off the tip then back it down till it just rests on the tip. Then give it oxygen.

Do you still have the propane up at 15-30psi?

I tried to turn on the oxygen with the propane flame touching the tips or not, it doesn't matter. Get the exact same flame in the end.

I tried with Oxygen at 7 and 15 (because this is what I found online) and 30 (because I feel like I don't have enough propane coming out compared to oxygen.

Maybe there is something clogged in the cutting head?

Propane needs more oxygen to burn than Acetylene does. Upping the propane is just going to make your issue worse and can lead to the same popping. You want a roughly 4.3 to 1 ratio of oxygen to propane.

What is likely happening is since you have too much fuel gas going through, you're having to have the fuel knob barely opened otherwise the flame, without oxygen, would be far too much, so you lose any fine control and decent flow through the torch. Having the propane pressure lower will let you fine tune the flame better.

This happened a lot with the last guy I taught gas welding to. He kept upping the propane pressure trying to fight the torch popping but it only got worse and worse.

Go for 5-10psi on the Propane, 35-45 on the oxygen. Crack the propane and get a flame, then add a little more. Add some oxygen, add some propane, add some oxygen, etc, until you reach the desired neutral flame. If you go right to knobs wide open you'll always have issues.

I don't have a cutting head anymore, but always ran the regulators set the same whether I was cutting, using the big torch, or using a baby torch.

Ok, so I dialed down propane to 7 and kept oxygen to 40.

Same issue, I think it's worst.

https://youtu.be/NgTfB5tRReo

I started with propane and then turned it down a little bit. I opened oxygen a little bit until the inner flame was almost in the tips. I then added a little propane, but it was already maxed out after around 1/4 of a turn. I then added a little more oxygen (less than 1/8 of a turn) until the inner flame was, again, almost inside the tips.

I tried to add more propane but saw that I was already at the maximum. At this force, I won't do anything good with it.

Added a little more Oxygen just to show that the inner flame goes inside the tips and the flame shrink and die.

Does your tank have enough pressure to feed the torch? Is the regulator dropping a ton once the gas starts flowing? How are the o-rings on the cutting head?

At a steel mill, I used natural gas/O2 as my cutting flame. I had no control of pressure; It came from a manifold. There was a learning curve. I found that, unlike oxy/acet, I had to approximate the mixture before I tried to light it. There was no "turn on the gas, light it, add the oxygen". It simply wouldn't work. I would expect, due to similar chemical composition, that LP/O2 will behave the same way. You will have a learning curve to mix the right amount of LP with the right amount of O2 to get it to light reliably.

Steve

That way works or light it holding the tip touching a piece of scrap or your bench at a shallow angle like maybe 15 degrees - it will stop the oxygen blowing the flame off the tip or out - it's how we always light oxy/propane out doors - takes a little practice as you need to get it lit with the flame on the tip & increase both gases gradually to achieve the size flame you need - or if you have a good idea of how far to open each valve Steve's way works fine as you can usually relight with the torch settings untouched if you lose the flame mid cut.

Thanks all for the tips. I tried to light it like Steve or noddybrian explained but it didn't work.

I finally decided to buy a new cutting head and.... it works !

I bought a Victor 1350 cutting head only and installed it on my handle and it worked on my first try,

Here a small video to show how it is now: https://youtu.be/CCbqZ8zGSfo

I still need to practice on how to adjust it to the right mixture and how to close it properly, but it works.

Is it normal that the end of the head (the brass part) and the two metal tube become really hot? Like unable to touch it after around 30 seconds of usage?

Thanks again!

Glad you have it more or less figured out - it's difficult to comment on your equipment as UK gas cutting is mostly done with a cut only torch - only the lightest of hobby / art type work is done with an attachment such as yours but in general the torch / pipes should not be hot except for how much radiant heat they get from the material being cut- if it's getting hot quick this is usually caused by " flash back " or the flame traveling back from the nozzle which is not good & time to shut everything off before " something bad " happens ! sorry I can't be of more help - the video appears to show a fairly normal use-able cutting flame though it changes more than is desirable when the cutting pressure is applied - I think this is fairly typical of attachment styles & is less noticeable on proper cutting torches - just for $#its & giggles if I can still find one I'll dig out the old BOC / Saffire torch & try the cutting head to see if it does the same.

Personally, to me setting the gauges I always went for max. Course max for acetylene is 15 PSI. On propane & natural gas I usually turned the gauges up to 40 plus each. Then fine adjust it at the torch. The high pressure that I use is because I don't want to go back & forth to adjust increase the pressures on the gauges. I set it for max all the time. I worked as a Journeyman Pipefitter in the industrial setting for 28 years & and a contractor for 10 years. You get sick & tired of either climbing out of a ditch, climbing down from walking the iron to adjust the gauges for your torch. And, you never know if you will be heating or cutting. Or maybe even cutting with a pipe filled with water. Oh, and you can do that. Or maybe even cutting cast iron pipe. And, you can cut cast iron pipe with a torch, you don't need to air arc it all the time you can use a oxyaceytlene torch to do it. If you know how to do it. Your case, for propane crank the gas pressure up. What you want is blue cones about a 1/4" long at the tip of the torch. Hit the trigger & start cutting.

mr_sarge wrote:Thanks all for the tips. I tried to light it like Steve or noddybrian explained but it didn't work.

I finally decided to buy a new cutting head and.... it works !

I bought a Victor 1350 cutting head only and installed it on my handle and it worked on my first try,

Here a small video to show how it is now: https://youtu.be/CCbqZ8zGSfo

I still need to practice on how to adjust it to the right mixture and how to close it properly, but it works.

Is it normal that the end of the head (the brass part) and the two metal tube become really hot? Like unable to touch it after around 30 seconds of usage?

Thanks again!

It seems like you are on the right track.I just switched over to propane and like it a lot better and a lot cheaper.You will not get the exact flame as Acc.and will have to adjust about 3 times. But i found that it cuts the same or maybe better.I put the Acc. tank in the shed and mounted a 11# tank on the cart and never looked back.Now welding is a different story.But that has been replaced with Tig and a Miller 211.But Brazing is good if you have to.

Cutting with propane works better with more tip stand off distance than cutting with acetylene.

Each of the three gasses I’ve used to cut require different tips. Acetylene, LP, and propylene.