Plasma or oxy/acetylene? Specifically for cutting...

[1320stang]

So I know there are advantages and disadvantages to both. But I was thinking costs of running it in a cutting scenario. I don't see myself cutting anything thicker than 1/4", but mostly sheetmetal on cars and frames. I'm not on a farm, I don't recall needing to heat something up to remove it too many times in the last 40 years that a propane torch wouldn't do.

O/A is simpler and doesn't go out on you unless you run out of gas. Plasma consumables are not universal and maybe they obsolete your model.

I'm just wondering if its a wash as far as the consumables. I have a 6hp/80 gal 175psi compressor.

 

[ItsNemo]

O/A will run literally anywhere and is more versatile (can cut, weld, heat, braze, etc.) but running costs are higher.

Plasma is easier and cleaner and more precise but you're tethered to a lot of equipment.


Also, as long as you buy a name brand plasma cutter, you should be able to get parts for a long time (e.g. hypertherm, thermal dynamics, miller, etc.). If you buy a $300 box off amazon, ya, good luck with that.

If I could have only one, it would be O/A (or even O/P) but I'd rather both and this is GJ after all lol

 

[Boogerman]

plasma much cheaper for me; consumables almost no consequence; O/A expensive buy gases. O/A more versatile; you say not important to you. Plasma safer, more convenient to store. O/A portable; plasma tethered to air and electricity.

 

[finn]

Get both. I couldn’t live without the OA for heating., but prefer the plasma for cutting, because it seems safer.

 

[mogandave]

If all you want to do is cut sheet, plasma is fine.

OxyA is typically easier to control, and you can also weld, braze, solder and heat. It will also provide a much better (less kerf) cut on thick material. Even the smallest OxyA outfits will cut 3-4" thick material with the right tip.

 

[1320stang]

I have a couple O/A torch bodies, hoses, tips, a bottle cart and an old, small, maybe 60-80cf bottle. I guess thats another factor, how big of bottles do you get? You're right, gas is expensive and fluctuates. Bottles are hard to buy right now, I had to rent my TIG bottle, I bought my MIG bottle many years ago, think I paid $80 for an 80cf bottle in the late 90's.

It wasn't so much about the upfront costs but the running costs. Another thought of an advantage to the plasma would be if I got a small CNC table for it later.

I once rented an O/A setup in the early 90's to cut up a wrecked mini truck I'd bought for the GFX kit and convertible top kit. I didn't know you should close the valves after every use so the gas didn't all leak out, I could have bought a new setup with full bottles for the $600 I owed at the end (I'm sure they saw me coming). It was an expensive lesson. Now, if I stop MIG welding for more than a couple minutes I shut the valve.

 

[cherokee]

I had used O/A for years, finally after they got an el cheapo off amazon here at work to cutup and modify a trailer I bought the same thing. I have not touched the torch again. For heating, again an el cheapo induction heater. Works great, just don't use it on bolts on leaf springs if the rubber is still in there, the amount of smoke was just amazing....and the smell. Yes you are tied to the wall, but big deal. I am not out in the field anymore.

 

[Firebrick43]

I have a couple O/A torch bodies, hoses, tips, a bottle cart and an old, small, maybe 60-80cf bottle. I guess thats another factor, how big of bottles do you get? You're right, gas is expensive and fluctuates. Bottles are hard to buy right now, I had to rent my TIG bottle, I bought my MIG bottle many years ago, think I paid $80 for an 80cf bottle in the late 90's.

It wasn't so much about the upfront costs but the running costs. Another thought of an advantage to the plasma would be if I got a small CNC table for it later.

I once rented an O/A setup in the early 90's to cut up a wrecked mini truck I'd bought for the GFX kit and convertible top kit. I didn't know you should close the valves after every use so the gas didn't all leak out, I could have bought a new setup with full bottles for the $600 I owed at the end (I'm sure they saw me coming). It was an expensive lesson. Now, if I stop MIG welding for more than a couple minutes I shut the valve.

I have a full size T size oxygen bottle and a midsize #4 size acetylene bottle as they will run out relatively close to the same time.

What are you cutting? Scraping or cutting used metal that has paint/rust is going use more consumables and isn't going to go as well as an O/A torch. Also there are drag tips for cutting sheet metal for a torch that many don't know about and do a cut thats pretty close plasma.

My father had a large Hypertherm for repairing aluminum trailers. When he retired from that he sold it but still has his torches.

 

[1320stang]

I don't see myself cutting anything thicker than 1/4", but mostly sheetmetal on cars and frames.

 

[boom_bap]

You claim to know the pros and cons above but I'll just throw this out there for readers.

I don't think anyone has mentioned that you can only cut ferrous material with OA? If you don't already know how OA works that would be a good thing to learn. Jason Becker has an excellent safety video on OA cutting as well on weld.com youtube channel. OA needs some training before I'd recommend just going out and buying a setup. Plasma on the other hand can cut anything. You need a good high SCFM compressor and clean dry air or you'll burn through consumables, which you have.

You are going to warp the snot out of sheet metal with OA. I'd just use a grinder, plasma works too but again youre going to put a lot of heat into the sheet metal.

If you're going to pick one, plasma for your setup and application for sure.

 

[mogandave]

You claim to know the pros and cons above but I'll just throw this out there for readers.

I don't think anyone has mentioned that you can only cut ferrous material with OA?

Great point this ...

 

[jmdirk]

I like my plasma. Sits on the bottom of my MIG cart, so it doesn't take up any extra room like a couple of OA bottles would. Bought a box of consumables when I bought the plasma and still have tons left.

Name brand box, you'll likely be able to find consumables for the foreseeable future. Even a Chinese box, there's so many of them out there that I'm sure you'll be able to find consumable for ages to come.

 

[1320stang]

My thinking for cutting up stuff is just for rough cuts as far as sheetmetal goes. For example, cutting the floor pan out of my '65 Mustang coupe, so its easier to get to the spot welds on the inner rockers and torque boxes. Rough cutting brackets to tune them up with a flap wheel (even with protection, I see why they call it the wheel of death).

 

[dnschmidt]

With respect to things heating up with plasma this is a non-issue if you're cutting 20 gauge sheet metal. The plasma is so fast that you'll barely notice it. You can cut 20 gauge basically as fast as you can comfortably move the torch. and you have the advantage that you can guide the torch with any piece of angle iron or box tubing that you've got laying around and get a perfectly straight line. I don't like flame for several reasons. 1) It's sort of hard to turn off an o/a torch. You've got to turn off two valves sort of at the same time and they are located in a rather weird position. With plasma you just let go of the trigger. With respect to brands I suggest one of these two. Hypertherm or HTP. Hypertherm is USA and HTP is Italy. Both work great.

 

[jpmidwest]

i work in autobody and we dont own a plasma cutter right now but this year we are going to pick one up because it will drastically speed up the cut process on sheet metal parts and making metal patches will be easier. we have a O/A set up but we rarely ever bust it out, we only do when there are stubborn bolts on truck beds, truck bumpers and that pretty much it. so for you i say buy a plasma cutter just for ease of cutting and convenience for you.

 

[u3b3rg33k]

I've done both, and for MOST things I prefer the plasma, especially if you're cutting on something assembled, you're either re-lighting your torch constantly or holding it while you stare at the work. with plasma, just let go of the trigger, and you've no longer got an active light saber.

 

[speed bump]

If you are never going over 1/4" then plasma all the way. While I probably wouldn't go without a O/A torch for the garage I but don't use it for cutting anything smaller than 1/2" unless I'm mobile.

 

[1320stang]

That's my other thing, I'm only on an acre and a half, the detached shop will be pretty close to the house. We had some big fires that swept thru north of OKC a couple weekends ago. This week I had a guy come out to remove some trees where the shop will go and had him pull all cedar trees where he was working.

 

[kwb]

I inherited my Grandpa's OA setup. I use it periodically - mostly for heating things, usually to remove galvanizing in specific spots on parts I have dipped. I think in the decade I have had it I might have swapped bottles once.

My technique could use some work but even guys that are good with an OA cutting torch, my Plasma will do a better job, faster, with a cleaner cut and less residual heat, and that is with my 45A machine. I could take the 65A machine off the CNC if I had something really thick to attack.

99% sure that if I was cutting equal number of feet of equal material OA costs will be a lot higher than consumables for the plasma but honestly I just buy the consumables in bulk and forget about the cost (until inventory gets low)

Plasma is a higher cost to entry by about double if starting from scratch for each.

 

[Walkers]

As a guy who uses both every day for work, get the plasma for cutting. Much, much better for a hobbiest to use.

 

[arrowhead]

If I had to to choose one it would be plasma. Plus, you can get units that have their own air supply if you don't want to deal with a compressor and hose, but those are usually smaller I believe. As far as thick cuts, plasma with go pretty thick but it depends on the power available and the size of your check book. I got a Hypertherm 45XP with hand held and machine torches. They make many different tips for the torches like gouging, marking and flush cut.

 

[rsanter]

I use my plasma way more
But sometimes I need that OA

 

[u3b3rg33k]

plasma can also cut anything conductive/metallic. OA will only cut things that you can oxidize easily. so from a "can I cut it" standpoint, plasma is usually a yes.

 

[txvwnut]

If your needs are just cutting and you’ll be doing it close to your air and power supply then plasma all the way. I use my plasma way more than my torch. I have it and my tig welder on the same cart so I have cut and weld operation together wherever I need it.

 

[welder4956]

For automotive cutting work, I haven't found anything that would be better cut with plasma or OA instead of a cutting disk on a grinder. Floor pans, body panels, bolts and exhaust pipe/hangers are easy cuts with a grinder. The OA would be helpful if you need to heat stuck bolts for removal or cut bolts where there is not enough access for a grinder. I have an air plasma cutter and rarely use it, mostly for 1/4" and thicker.