How to use a cutting torch

[irish fixit]

While I realize that we've covered much of this in another thread (see http://weldingweb.com/vbb/showthread.php?t=62703) and I'm sure this subject has been covered before. However I quick search didn't bring it up. I thought I'd start another thread with a simple title that might be easier to find. I also decided to try my hand at movies one more time to see if it might help some of the beginners. I don't even know if the last ones I did where even seen being buried in the other thread.

Anyway on with the show. I hope these are a help to somebody.



Maybe this well embed this time. I've got some more video's uploading right now so we'll try it again if it doesn't

[Tec]

Thanks Irish Fixit.

Your video just showed that I wasn't adjusting my torch properly. I just started getting back into using my O/A outfit, first job was cutting up some dozer tracks. I had a lot of slag and some welding back together behind the tip, just an ugly mess. I had O at 20 and A at 5, I also didn't adjust the flame with the oxygen trigger on.

Thanks for info, Tom

[irish fixit]

You're welcome. I don't pay to much attention to the acetylene pressure other than keeping it under 15. I know I was running around 7 this time around but I often run higher since I use large rose buds fairly often.

Here's the next. I have two more after this that are still uploading. I'm going to try and add to this as I have time.

[mla2ofus]

Very good, Wayne!! There's been a lot of attention paid to joining iron here, but very little to cutting it. I'm sure a lot of folks here will appreciate your efforts. If you feel up to it maybe a little video on plasma cutting would also help some folks here.
Again, Thanks,
Mike

[irish fixit]

Thanks. I'll see about getting the plasma sometime as well.

Cutting does seem to be a subject that's overlooked here. Yet it can be as important as the welds.

Here's the next video. I have one more uploading at the moment.

[kburd]

This is amazing I have been fabricating for about ten years and have never been one of those guys who could cut great with a torch I could get it good but not that real clean smooth cut. That top melting is a problem I just assumed you had with o/a. Now I realize that is because I wasn't properly adjusting my cutting flame. Multiple welding classes and nobody ever explained that! I know different tips for different jobs but do you find you have one that cuts most material between 3/16 an 3/4 well for you?

[farmall]

Pic of the style torch he's using. Fairly plentiful on Ebay, and OADoctors site has seal kits if I recall correctly.

[irish fixit]

This is amazing I have been fabricating for about ten years and have never been one of those guys who could cut great with a torch I could get it good but not that real clean smooth cut. That top melting is a problem I just assumed you had with o/a. Now I realize that is because I wasn't properly adjusting my cutting flame. Multiple welding classes and nobody ever explained that! I know different tips for different jobs but do you find you have one that cuts most material between 3/16 an 3/4 well for you?

Don't feel bad. It was at least 20 years into my using a torch before I started figuring some of this stuff out. It also seems that it's one of those things that people either won't or don't know how to explain. I know I asked a lot of people how to improve my cuts with no real answers coming back.

As for the tip size. If I had to have just one tip it would probably be the 1/2" rated one. That's what I keep on my truck. It will cover most things if not perfectly at least well enough. It pretty tough to make a perfect cut in the field out of position with the wind blowing anyway.

Pic of the style torch he's using. Fairly plentiful on Ebay, and OADoctors site has seal kits if I recall correctly.

That's it alright. I must say I'm biased since my first torch I bought when I was 13 was a Purox. I retired that handle the first of last year finally and my cutting attachment is off to have the tip seat reamed at the moment. As you say they're fairly common on ebay and if your patient pretty darn cheap to boot.

Here's the last video for tonight.

[BlackGT97]

Do they use the term "slag" in industry? What i mean is, is the term slag, when using o/a cutting, acceptable? i learned that the correct term is Dross. Just want to know if you guys use this term when talking about oxy acetelyne cutting. You only get "slag" if you are using flux...right?

[BlackGT97]

Just watched all your videos. Great videos for showing how to properly do oxy acetelyne cutting. I loved cutting with oxy actelyne in school. I got fairly good for only having two weeks. Nice straight cutting lines and very little Dross/slag. I think the biggest factor is the torch, and how the flame is set. The fist thing the insturctor told us, is to adjust it like you did in the videos.

[DSW]

Very good vids there Wayne. It's nice to see someone who truly knows how to use a torch. Shows the new guys that you really don't need to spend a lot of money on a plasma to get nice clean cuts. Simply knowing how to cut with an OA torch and getting the settings and travel speed right will go a long ways to getting a very nice clean cut.

[handtpipeline]

Those are good videos, and very informative. 7PSI on the gas (Acetylene) and 40PSI on the oxygen is what I was taught as a general rule, and it usually works about right. I've had to turn the oxygen up some on thicker stuff like you demonstrated.

We scrapped some old junk this past summer, and I had two OLD trenchers that I wanted to keep the motors out of. We had re-powered them several years ago with Deutz diesel engines, replacing the original hercules and red-seal gas motors. Anyway, one of my guys working for me said he could use a torch, so I let him cut on them while I was doing some other stuff... Somehow, I still havn't figured out how, he used up an entire tank of Acetylene, while only using about 800 pounds of Oxygen. And I ended up having to re-cut most of what he attempted to cut... His cuts fused themselves back together... I know he didn't have the torch set right, but my gawd, how did he use so much Acetylene??? I carry 2 Oxygen and 1 Acetylene tanks on the truck, and usually it works out where I change all of them at the same time. I know the regulators were set on 7 and 40, because I made sure of that before I turned him loose, and he said he knew how to set a torch... Of course he told me he could weld once too... took about 30 seconds to figure out he was wrong about that... then a couple of minutes to grind out what he did... It wasn't anything critical, just scabbing a plate on the bottom of a rock box where someone had stuck the trackhoe teeth thru it, but it was REALLY ugly...

[Drf255]

Awesome videos!

Thanks so much. Do you think you can do one just on gas pressures and flame adjustments?

[fran...k.]

Those look like some pretty flexible gloves for the size of them.

What I see missing is using a block under the hands as the thickness of the piece increases. These videos show cutting an object at it's thickness above the surface to rest the hands on. That torch's dimention from the end of the nozzle to the centerline of the handle is less than most and the propane guys will want to have more hold off. Obviously you have a steady hand and have perfected your technique. Once you make one cut it pretty much preheats the piece so less preheat flames would be necessary for another close cut.

[irish fixit]

Do they use the term "slag" in industry? What i mean is, is the term slag, when using o/a cutting, acceptable? i learned that the correct term is Dross. Just want to know if you guys use this term when talking about oxy acetelyne cutting. You only get "slag" if you are using flux...right?

Dross is probably a more correct term. I've had very little formal training so sometimes I use the wrong term for things. I'm not sure of the true definitions of the words.

Just watched all your videos. Great videos for showing how to properly do oxy acetelyne cutting. I loved cutting with oxy actelyne in school. I got fairly good for only having two weeks. Nice straight cutting lines and very little Dross/slag. I think the biggest factor is the torch, and how the flame is set. The fist thing the insturctor told us, is to adjust it like you did in the videos.

Thanks. I think the torch is important but even more important is the tip. A good tip is needed no matter the brand of torch. It's just that some torches have better tips than others.

Very good vids there Wayne. It's nice to see someone who truly knows how to use a torch. Shows the new guys that you really don't need to spend a lot of money on a plasma to get nice clean cuts. Simply knowing how to cut with an OA torch and getting the settings and travel speed right will go a long ways to getting a very nice clean cut.

Thanks. That's what I'm trying to impart with these video's. Still pictures don't show enough of the story about travel speed and how the cut acts. It's taken me 35 years to get where I am with a torch now. Most of it figured out on my own. I'm trying to help some people cut that learning time down a little. Hopefully I'll learn a few things along the way as well.

Those are good videos, and very informative. 7PSI on the gas (Acetylene) and 40PSI on the oxygen is what I was taught as a general rule, and it usually works about right. I've had to turn the oxygen up some on thicker stuff like you demonstrated.

Thanks. It's my normal pressure for most cutting. I'm not one who changes his regulators at all the time. Mostly just the oxygen pressure depending on what I'm cutting and what tip I'm using. I will sometimes turn them down when using a really small welding tip. High pressure makes those really sensitive to adjust.

We scrapped some old junk this past summer, and I had two OLD trenchers that I wanted to keep the motors out of. We had re-powered them several years ago with Deutz diesel engines, replacing the original hercules and red-seal gas motors. Anyway, one of my guys working for me said he could use a torch, so I let him cut on them while I was doing some other stuff... Somehow, I still havn't figured out how, he used up an entire tank of Acetylene, while only using about 800 pounds of Oxygen. And I ended up having to re-cut most of what he attempted to cut... His cuts fused themselves back together... I know he didn't have the torch set right, but my gawd, how did he use so much Acetylene??? I carry 2 Oxygen and 1 Acetylene tanks on the truck, and usually it works out where I change all of them at the same time. I know the regulators were set on 7 and 40, because I made sure of that before I turned him loose, and he said he knew how to set a torch... Of course he told me he could weld once too... took about 30 seconds to figure out he was wrong about that... then a couple of minutes to grind out what he did... It wasn't anything critical, just scabbing a plate on the bottom of a rock box where someone had stuck the trackhoe teeth thru it, but it was REALLY ugly...

Ouch. I can't imagine how he could go through that much acetylene. It's nearly impossible.

Awesome videos!

Thanks so much. Do you think you can do one just on gas pressures and flame adjustments?

Thanks. I'm going to try and cover a lot of things. Gas pressures is one I might though you might go to the thread I referenced above to see what I've wrote about those there. I've got to figure out a filter setup so you can actually see the flame in the vids/pics.

Those look like some pretty flexible gloves for the size of them.

What I see missing is using a block under the hands as the thickness of the piece increases. These videos show cutting an object at it's thickness above the surface to rest the hands on. That torch's dimention from the end of the nozzle to the centerline of the handle is less than most and the propane guys will want to have more hold off. Obviously you have a steady hand and have perfected your technique. Once you make one cut it pretty much preheats the piece so less preheat flames would be necessary for another close cut.

Yes they're fairly flexible. They're not as flexible as TIG gloves but offer more protection. On small delicate stuff TIG gloves work well. But I've gone to using these MIG gloves for most things that don't put out a lot of heat. They're more comfortable and make things like cutting easier. Those are simply Tillman 1350S (I have small hands). In truth that's not the best fitting pair I've had but they work.

Good catch on the support. I thought about that after I finished the video's. I'm so used to it that I can tilt and spread my left hand enough to make up for the height to a certain extent. But I often use blocks of one form or another to help with the support. I was working on keeping these simple for a start and working up to the more advanced.

Yes the piece having heat in it already made the cut with the low preheat much easier. It's still possible if you're perfectly steady and have clean material to cut a cold piece with low preheat. But it's all to easy to loose the cut.

[wirehead]

It would be really cool to demo another video, this time turning off the acetylene after starting the cut to demonstrate how oxygen cutting really works (unlike plasma cutting where molten metal is just blown out of the kerf)

[irish fixit]

It would be really cool to demo another video, this time turning off the acetylene after starting the cut to demonstrate how oxygen cutting really works (unlike plasma cutting where molten metal is just blown out of the kerf)

I'll see about it if I have time. It's actually tricky to do. The main problem is keeping the torch steady while turning the preheat off. It's a lot easier if some one else is doing the preheat with another torch to start it off.


Here's another video. It's not the one I was going to do first but you tube let me wait 3 hours for the other to load before telling me it was to long. I had to break it up and start uploading it again.

Anyway this shows how to clean a tip.

[bigb]

Thanks for the videos, just what I needed as I am working on getting better with my OA.

Also, I like your table. I have a heavy framework ready for my cutting table but haven't decided on a top yet. Can you post up the details on yours or maybe a link if you already have?

Thans

[farmall]

If anyone wants to save these videos, the Downloadhelper add-on for Firefox works well. If you save them as .flv files, vlc media player will play them. Both free with no adware/crapware.

[irish fixit]

Thanks for the videos, just what I needed as I am working on getting better with my OA.

Also, I like your table. I have a heavy framework ready for my cutting table but haven't decided on a top yet. Can you post up the details on yours or maybe a link if you already have?

Thans

You're welcome.

Ah the table. Well yes I have made a thread on it a while back. It was just built from junk about 20+ years ago. I did build it with cutting in mind though. Here's the thread for it.

http://weldingweb.com/vbb/showthread.php?t=55763

One note on the table. If I was building it today with new materials I'd use something other than the expanded metal for the back.
Either square tubing, solid square, or angle iron spaced would be better materials.

Here's the first of three parts for the main video I did today. I covered a fair amount of ground with it but I know there's lots more to cover.

[irish fixit]

Here's the next segment in this video.

[irish fixit]

Here's the last segment of this video.




Here's the two videos I placed in the other thread. I was still learning on them but they may show some things. I uploaded them in HD but I've had to quit that because of the long upload times.






I just got a chance to view these after uploading. I think I will try to upload a little higher resolution versions over the next few days.

[mla2ofus]

Wayne, you've covered more ground on how to use a cutting torch w/ this thread on this site than I've seen since joining.
Mike

[Scott Young]

Your video "Adjusting a cutting torch and other tricks 1" is the best description for setting a torch flame I have come across. At the shop I worked at a man couldn't run a torch on a money job unless he could acheive that setting. Each tip is rated for different thicknesses and like you have mentioned a single tip can be used from very thin to thick by adjusting the preheat and O2 pressure but your loose that cherry spot where the flame lengthens and has the little whipping sound when the O2 is pressed. The absolutely best cuts come from when a flame and tip are in that cherry spot.

I was responsible for teaching all the new guys the ropes on cutting at the last shop I worked for. It was interesting to see seasoned weld hands response to the class. many were angry they had to take a cutting class. many of them could outweld me by miles but when it came to cutting blind beavers could have made prettier cuts. After the class, many of the ones that were angry at the first were making great cuts. I think mostly it was their pride being bruised alittle.

Bracing is most important thing in cutting, and a clean tip is it's twin sister. if you can't have those two thing you won't have a good cut. I will never forget when on of the welders scare everyone by cutting a 24" diameter 3 inch thick slug and it fell though cause the cut was so clean. It was common practice to weld a pad eye on the slug to lift it out of the future manway opening. seems the welder typical had to beat with a sledge on the slug and curse at it for while before it would give up and come out. He was sitting on top of a 120" can and was just finishing his cut when the slug slipped through the opening and came crashing down on to a buggy feeder underneath. the man inside had to clean his drawers. With all the crashing and cursing we though the slug had landed on the man. After the incident write up the welder who had cut out the slug was so proud that the cut was a through and through and he didn't have to beat on the slug to get it to come out. Before anyone says the pad eye should have been welded on before the safety cuts are cut, in the welders defense, in all the years he worked there he had never ever had a fall through. ALL of his cuts were in need of a big hammer and the power of the crane to pull the slug out. You gotta love a clean cut. He was using a victor 315 with a number 4 cutting tip.

Thanks for posting the videos.

[davec]

This is some great stuff. I really want to thank you for taking the time to do this. As you noted, there just isn't much info out there on the details that make cutting work. I know I have a loooong way to go myself. The problem is that some of these shots need to really be zoomed in a lot more as I just can't see details (things like you describing the flame as you adjust - you can't see what the flame is doing well enough to match up with your comments).

I don't want to take anything away from this, as I greatly appreciate the time you have spent doing this. I'm just trying to get any last bit of info I can.

I've had good luck using the easy (and free) Windows Movie Maker in the past to stitch together multiple video clips, so that could be an option, if you are interested. Or just even some close-up shots in separate videos. I'll take anything!