Acetylene vs propane - torch purchase

Was reading 135 Fan's threads on potential torch rental business and "crazy information" on torch pressure settings and got a little nervous as I'm about to spring on purchase of an O/A torch setup.

I was going to go "propane" until the Praxair store quoted me $400+ for a propane torch kit vs $160 for Acetylene. I've got the oxy cylinder, size M, already and he'll trade me another oxy cylinder (that I can get for free) for a new acetylene one, size 3. Guy said fuel cost between A/P is about the same. Comments?

I've already got a small oxy/mapp torch that I've used for brazing/heating/cutting but its just too small for the projects that I'm starting to get into. I'm mainly going to use it to heat/straighten tractor/implement parts & repairs, cut rusted bolts, etc. I've got a buzz-box for welding, so don't anticipate using it to weld.

My question: Is Acetylene more dangerous for a "non-pro" than propane?I'd been looking at used torches on craigslist and at auctions but am leery to get one "cheap" and find out the regulators are bad or something else is wrong with it, especially when it could be safety related. Those are things I've read on this and other forums and why I'm planning to buy new. I figure that if I buy a new set, read the manuals and browse the net for info, I should be "safe". Agree?

That's kinda like asking which is safer a .22 or a .44 both will
kill/hurt you if you don't know what your doing. For my $ I
would avoid propane at all costs, I HAVE to use it at my job
but at home I use acetylene for a multitude of reasons. As
far as safe as long as you have good hoses,flash back/check
valves and some common sense you will be fine.

Neither is anything to be afraid of as long as you use flashback arrestors on the lines. As far as which gas to use though I"d say aceteylene is by far the best choice. Propane is a good, cheap fuel when you are using alot of it for for something like cutting up scrap, etc but if your wanting something for general use then chose acetylene.

you have to be careful buying used torches, they can get really abused

but, if you can find a good quality torch at reasonable price and get it rebuilt properly, you can possibly come out ahead

cheap new torches are cheap for a reason

One thing to take note of is that you can buy propane 24/7 at almost any corner store, long after the welding supply place is closed. I use propane and acetylene at home, and all i have to switch is a tip on my torch (and the regulator from one tank to the other). Acetylene burns quite a bit hotter- therefore you can cut thicker stuff a little quicker but propane will do everything acety will.

As far as the danger goes, DO NOT turn your fuel gas above 13 psi- acetylene particularly becomes unstable above that pressure and can combust.

The only thing I do to use LP on a standard torch is change the tip to a propane tip and adapt the regulator to fit the LP bottle. 50 bucks total at most.
Beyond that... choice between LP and acetylene is your call. For me... LP is cheaper overall and I find it just as functional for what I do. It's not as good for brazing because I could never make it burn through a standard welding tip... but for the little bit of brazing I do I can use the cutting tip and get along fine. Mabey that's why he's quoting you the big price difference... to give you welding tips for LP. Your call there as to which you need most.

Rod

I've had cheap Chinese torches and much-more pricey Victor. No problem with either, and they both use standard tips, easy to get at any welding store.

You can buy propane tips to fit most acetylene torches.

You can also buy single-stage regulators, or two-stage. Chances are you'd never notice the difference for most types of shop work. Two-stage gives a more steady pressure and can be nicer to use for long brazing jobs that require a steady flame.

As to choosing propane instead? Oxy-propane doesen't burn near as hot as oxy-acetylene - but both will cut steel. Just takes more patience with the propane. Most of the scrappers and junkyards in my area use propane since all they do it cutting, and it's cheaper. For low-volume shop work, I much prefer the acetylene.

Oxy-acetylene burns 6300 degrees F.
Oxy-propane burns at 4300 degrees F.
Most steel-alloys melt around 2600 degrees F.

I recently bought a new torch set with brazing tips, cutting tips, two regulators and hoses on Ebay for $89 and it's been working great. Just bought it as a spare.

Hi JML,

Here's a good discussion about using propane from someone who used to post on this forum about ten years ago. It's quite long. If it doesn't post, I'll e-mail it to you, if you want me to.

Stan

Posted by Mark Kw on May 27, 2001 at 06:12:59 from (216.37.229.149):
In Reply to: Cutting torch kit posted by Steve in CT on May 24, 2001 at 10:09:03:
A couple things on this one; first, most all Generico stuff is interchangeable with Victor, from tips to valve seats and regulator diaphragms. I've been using Generico regulators for about 7 or 8 years now on a daily basis with no problems yet.
I don't like acetylene very much and prefer to use LP for 99% of everything I do. If you want to use LP, you need to know a few things. First, you must use type "T" hoses with LP. The normal hoses used with acetylene will become soft and blow out after time exposure to LP gas. Anchor brand hoses are cheap and to be honest with you, they are the best I have ever used, remaining pliable in extreme cold is their biggest plus for me.
Next, you need a torch specifically designed for use with LP or it will not work properly. The Harris type "F" is designed for use only with LP/MAPP gas and is the only one I have found that will mix the LP/O2 to give a proper burn at the tip. One of these will run you about $140 with a #2 cutting tip. The best part of the Harris design is that the rosebud tips screw right onto the cutting torch tip threads so there is no changing handles.
Using LP takes some getting used to because setting the flame for different uses is slightly different from that of acetylene. For cutting, you need to use an oxidizing flame (very short light blue pre heat cone). LP cuts much faster, thicker and cleaner than acet once you have the proper torch/tip combo and get the feel of how to set it. One of the biggest plus sides to using LP is that you don't get the popping and blow backs when cutting dirty/rusty steel like acetylene does.
LP does require slightly more O2 than does acetylene but the end result is that you get much more cutting power for the same amount of O2 as with acetylene fuel gas. LP is also much safer too. Acetylene can self ignite when in gas form in the hoses/regulator if the gas pressure gets over 21 psi, LP will not even if the line gets full bottle pressure because of a regulator failure or operator error.
The myth that LP takes longer to pre heat or start cutting comes from those people who either used the wrong torch or the wrong flame setting. Too much gas at the tip will cause you to have a cold pre heat flame. Too much O2 will cause also cause a cold flame and make the cutting very slow and sloppy. In most cases of guys complaining about LP not being as good as acetylene come from them trying to use equipment that is not designed for LP use. The Victor and Smith adapter tips for use with LP on a torch handle designed for use with acetylene will not produce a proper LP/O2 mix and the flame and performance will suffer greatly. Properly set, I can hold a cut with LP on my Harris torch 2" to 6" from the work piece where with acetylene you will loose the cut when the tip gets 1/4" or more from the work piece.
The kerf of the cut from LP is also much easier to clean especially when cutting rusty steel. In most cases, I can cut heavy thick rusted steel with LP and do all the cleaning easily and quickly with a chipping hammer. Grinding is rarely ever required even if MIG welding the steel with solid wire. When done properly, the cuts from LP are confused with those made by plasma cutters.
For all the heavy duty cutting I do, I have yet to need an LP tip bigger than #2 and as a matter of fact, I don't even own any other size tips for it except for the rose buds. Adjusting the O2 pressure will control the thickness of the steel you cut while maintaining the same pre heat flame size and setting. I have made cuts on steel 10" thick that were clean and smooth with a standard #2 cutting tip but using 80 to 90 psi of O2 pressure. Yes, you do use more O2 but you are not using any more fuel gas for the heavier cutting as you need to do with acetylene. You save time because you don't need to constantly change tip sizes for changing material thicknesses. I rarely change O2 pressure settings because the cut valve on the Harris torches allows you to feather the O2 cutting pressure at the handle. This takes some practice but is a real time saver once mastered.
Now as for the tanks. A 20 pound LP tank will last for about 20-30 of the biggest O2 tanks known as the 292 size (the ones that are 10" in diameter and stand 5' high). A 3 or 5 pound LP tank is sufficient for any DIY'er uses unless you are running a large rose bud tip for long periods of time. You can buy the medium sized O2 tanks from most any gas supplier for about $150. What you need to ask BEFORE you buy: 1- will they exchange the empty for a full one or only fill your tank? 2- If they will only fill your tank, how long is the turn around time (time you wait to get the tank back)? 3- Are they going to charge you for the hydro test on the tank when it comes due (most run about $35)? Just FYI, most gas suppliers will exchange your tank if purchased from them and not charge for hydro testing and will offer you a transfer or buy back option if you move from their service area because some suppliers will confiscate tanks that are not branded with their name while other don't care or will do a dealer swap. You don't want to shell out $150 for a tank, move away from the area only to have to purchase another tank at the new location.
Some words of advice. Don't slack on price and size of the equipment. Get yourself a 16" Harris torch, the big heavy duty two stage Generico regulators, Anchor brand type "T" 50' twin hoses in 1/4" ID diameter and either Harris, Goss or NTT LP tips. If you decide to go with acetylene, get the heavy duty two stage regulators, 1/4" ID twin hoses and the Generico acetylene torches are fine with either Generico or Victor tips. Don't limit yourself to smaller hoses or a light duty torch because you will regret it down the road. The cost difference between going heavy duty and light duty for the entire set-up will be less than $100 and well worth the extra start up cost when you do not become limited by the size of the equipment.
As for me, the only things I use acetylene for is flame spray build-up using powdered metals and some very special cast iron welding where I need to add carbon in order to get a proper weld process. I brass and silver braze, solder and cut with the same #2 cutting tip. It takes time to get used to it and learning how to set the flame and gas pressures to get the tip to do what you want but once the learning curve is over, you save more time than you can imagine and don't need to have pile of specialized equipment to get the same type and amount of work done. If you have any specific questions, feel free to email me directly.

Here's the kit I bought for $89 awhle back. It's a copy of Victor and has worked great. I can get new tips at any welding supply place. Sometimes they can be bought for $79 with free shipping.

You can also buy brand new shop-sized tanks from many places for $80 each.

Ebay Item # 150523625022

http://cgi.ebay.com/NEW-OXY-ACETYLENE-WELDING-CUTTING-TORCH-KIT-FITS-VICTOR_W0QQitemZ150523625022QQcategoryZ67059QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D6%26pmod%3D150494080991%26ps%3D63%26clkid%3D5299303789425577106

I used Mapp Gas for years,I had to use different tips for it but it worked good, I have Acetylene for home use. Mapp was supposed to be safer

I don't agree with some of what's said in that old post. It's written by someone who obviously uses propane and therefore makes claims it's better. On thick material or scrap propane can be better because the heat is spread out more and not as concentrated as acetylene. That's also why the torch can be lifted higher off the pate. It doesn't make for faster preheat or cutting speeds though. There are probably millions of O/A sets in use. Used and set up properly, they are perfectly safe.

I've used a lot of both and also Mapp and Chemtane. The Chemtane which was hyped up as the greatest thing since sliced bread was the worst of all of them. Don't believe everything a supplier tells you. Mapp was a little better than propane but I much prefer acetylene for hand cutting. For one thing, the cutting tips are one piece and narrower than the two piece tips every other fuel gas uses. This makes it easier to see what you're doing and the tips don't get damaged as easily. They're faster and easier to clean as well. In a lot of cases acetylene does a nicer cut than a plasma torch. The key to a good cut is the right size clean tip, right gas pressures, right speed and most importantly, a comfortable position with a steady hand. Propane is cheaper but uses up to 3 times the O2 of acetylene so the difference isn't as great as just comparing the cost of the fuel gas. Acetylene can be used for welding as well. Unless you're doing lots and lots of cutting/heating or a supplier is too far away, acetylene is preferred for most home shops and occasional users. For heavy heating applications with a rosebud propane is a good choice because you don't have to worry about drawing the propane too fast from the tank. With acetylene you'd need a large cylinder and even have to manifold a couple together so you don't draw the acetone out. Most people don't do that much heating though. I'd recommend acetylene. Dave

I forgot to add that you don't need 2 stage regulators and the most heavy duty torch available. Medium duty is the most popular. When looking at torches try a few out and see which one is the most comfortable for YOU (not your buddy). I'd buy a name brand and not a generic copy because a torch set will last a lifetime. I prefer Purox and they have a lifetime warranty. I like the shorter turned up cutting lever on a purox torch. I find it easier to use and can flip it over when heating with a cutting tip so I don't accidently hit it and cut into my piece. Several good torch sets on the market. I'd buy from an established welding supply that carries extra tips and accessories. You want to be able to get tips and parts 10 years down the road. Dave

Acetylene can't go over 15 PSI. Propane and other fuel gasses can without problems. Dave

Thanks guys for all the input. What's evident is that this is not a clear-cut black/white issue. Kind of like trying to buy a car. Even though the opinions so far seem evenly split, I'll probably go with an O/A outfit due to price of the kit and the fact that my oxygen will probably last longer. What's interesting is that both Praxair and Mark Kw (in Stan's post) say you need a propane torch, not just a tip change on an acetylene torch, to switch to propane but a number of you seem to switch with no problem.

For most torches all you need to do is change the tip, regulator fitting and maybe the hose. I'd have to see what sets he was comparing. The $160 set is mostly likely a chinese copy set. The $400 set could be a name brand with the regulator already set up for propane etc. Don't get me wrong, I think acetylene is the way to go but the welding supply might quote a much higher price for a propane set because they want to sell acetylene. Propane is available almost anywhere. Acetylene not so much. Dave

I bought my propane setup at praxair, about 120 for the Victor
small series torch and regulator, 25$ for a propane tip, 30$ for all-
fuel rated hoses.

You don't use more oxygen to cut really, its just that you need to
preheat longer and it uses more while preheating. It was a fortune
for acetylene tank rental vs 25$ for a propane tank.

You don't need more oxygen for the cutting jet but you do need more oxygen for the preheat flame. Oxy/propane uses an oxidizing flame. Dave

Provided you drive the gas pressure up... the amount needed for the flame is a very small amount of oxygen. I really haven't noticed any increased use of oxygen. Probably 1-1.5 large O2 for a 20# propane bomb.
That's with a #2 cutting tip on a small Victor setup. That's for a mixture of cutting and heating.

Rod

I just wanted to point out that propane does use more oxygen than acetylene and comparing only the fuel cost isn't an accurate way to determine how much cheaper it is to use propane. Dave

The real trick is to match the acetylene regulator fitting or your torch set to the tank you want to get.

My torch comes with a CGA-510 POL fitting which is the standard fitting for your propane tanks that ift your barbeque grills and such as well as a larger size acetylene tank (I forget which one).

The little acetylene tanks you see sold take a CGA-200 fitting, the MC I think. The next bigger one takes a CGA-300 commercial size fitting. I think the B tank takes a CGA-520 fitting. All are male fittings by the way.

The tanks come in all different sizes. The little MC one originally made for motorcycles that used it for headlights. Someone else probably knows which fitting goes to which size tank.

If you don't have the right size, there is an adapter to buy as well.

I have known about propane for 30 years,,, all the pro's I know use it,,, I did not give it a try till 1999,,, since 1999 I have used 2 20 lb LP tanks and on my 3rd rite now... My set up hooked rite up to a LP tank, all I needed was the tip,,, I have a bottle of acetylene on hand just in case I need to braze something,,, I spec I will never use it up,,, It would figger to me that a gas supplier would B again LP and recommend acetylene $$$,,, I am no master just read what goes on here about a fire wrench and can do a rite good job (better than I use to anyways),, I would get'em both and park the Acetylene bottle in the corner just in case...

Its got so competitive around here very few pay rent on a bottle any more,,, You can take any bottle to any place and they will exchange it,,, its all about the gas $$$

I've been using oxy/propane for about 12 years now. I bought my regulators/hoses/backflow preventers/ head used from a family member (but they were in good shape) when I was 16.

I don't weld/braze with it. I use it to scrap, and for heating/cutting/bending in the shop.

I think I'm on the 4th propane bottle.. I lost count on oxygen though. I may use more oxy this way.. I don't know, but I use one bottle a year as a average anymore (I have the large bottle.. 301 maybe?? ) and it costs me $35 to $40 to exchange, and about $9 for propane as needed..

It works for me.. all I did was get a propane tip for mine, and good to go. Thought about goin to acetylene, but as the old sayin goes "If it isn't broke, don't fix it" Plus, I just don't see where I'll save anything by switching.

Brad

if you are only using it for cutting go with lp, if you braze (like I do) or weld with filler rod you would be wise to go with acetylene, Smith torches are still US made in Watertown, SD, Victor is good but Harris has really dropped their quality

It really depends on what you're going to use your torch for. Acetylene is hotter than propane and excels for welding. I don't think you can gas-weld steel with oxy-propane. Propane is a better choice for heating and cutting. Not only is it cheaper, but acetylene is limited by its draw-down rate. If you use up more than a fifth of the acetylene cylinder per hour, you risk sucking acetone out of the cylinder.

For versatility, I think acetylene is the way to go.

For occasional use propane is ok, but for a full time shop acy would be best ,it is easier ti light and adjust and just works a little better,but i do use propane/oxy in my home garage/just had to get the right cutting tips.

My uncles used propane and got my dad and I to use it way back in the mid 1960's. Never owned an acetylene bottle. Just general farm use. Works great. Nothing fancy to buy, just a propane tip for the cutting torch. Done a lot of brazing using the regular welding tips. Old 40# propane tank we found laying around somewheres. Take it down to COOP and get it filled every few years.

Gene

Lots of good tips/advice on this thread. Since it appears that you CAN use propane and acetylene with the same basic setup according to a lot of posters, I'm going to go acetylene to start and just make sure the hoses are multi-fuel and the torch can burn propane with a tip change. I'd like to have both since it appears that propane would work better for heating larger pieces, which I'm probably going to be doing some amount of. That's something that my little propane & oxy/MAPP torches don't do a good job at. Since cylinders are not a problem, I'd like to have the flexibility to use both a/p. My head's been kind of spinning with all the pluses/minuses and I figure it's time to just go ahead and get it before the wife grabs the money set aside for the torch purchase. (It's in my not-so-secret hiding place). Hopefully, I'll be making BIG fire in a couple of weeks. I've got 3 projects already that are waiting for the torch.

JML. When looking for hoses make sure they are a grade T hose which is good for propane, acetylene, and all gases. They also make a grade R and grade RM hose for acetylene but they aren't rated for propane. The CGA (cylinder gas association) rates them.

I don't know what an R or RM hose will do with propane but guess that it eats at the inside lining till the hose can expand and blow out.

My guess is that it may take years of occasional use to degrade an R rated hose but don't know. Besides I was always taught to close the cylinder valves and purge the lines after each use anyway. Kinda why they recommend using checkvalves nowadays.

Maybe some of the propane users here will check the rating that should be stamped on the hose somewhere to see if it is a big problem or not. I'll check mine later.

For me the fuel cost wasn't really the reason. It was to an extent... at the time I had a 100# bottle of LP sitting there for 10 years or more so I decided to buy a tip and use it up... but in the end the contract pricing on having the acetylene bottle around here for me is too much to justify relative to the extra amount of O2 that I use. Naturally those numbers will be different for everyone depending on contract/ownership costs and usage. Acetylene just doesn't pencil for my usage... but I say that with knowledge that I can go retreive MY knee high's from my brother's garage should I ever need acetylene... so I'm not stuck.

Rod

Hi jdemaris,

The Victor Oxy/Fuel Welding, Cutting & Heating Guide lists the neutral flame temperature of oxy/acetylene as 5720 F. and oxy/propane as 4579. Wikipedia figures were closer to those you stated. Wikipedia is good for what it's good for, but I'd be inclined to trust Victor on this one.

All the best, Stan

Acetylene is the only fuel that can be used for welding because it is a neutral flame and won't change the properties of the steel. The draw rate is 1/7th the cylinder capacity per hour but it can be exceeded for short periods. If you want to heat with a rosebud, get a bigger cylinder. If the cylinder is near empty, also not a good idea to use with a rosebud. However, if your only heating up to say 3/8" steel, you don't need the biggest cylinder or the biggest rosebud. I think about a 75 cu. ft. cylinder would be fine. Don't get the little puny cylinders. Talk to someone wtih experience at the welding supply. Dave

The exact temps mean little to me. I'm sure there are many variables involved not worth discussing. Main thing is they both cut steel, but propane can be slower and takes some getting used to. But, propane is much cheaper - at least for now.

(quoted from post at 13:25:20 11/30/10) Acetylene is the only fuel that can be used for welding because it is a neutral flame and won't change the properties of the steel. The draw rate is 1/7th the cylinder capacity per hour but it can be exceeded for short periods. If you want to heat with a rosebud, get a bigger cylinder. If the cylinder is near empty, also not a good idea to use with a rosebud. However, if your only heating up to say 3/8" steel, you don't need the biggest cylinder or the biggest rosebud. I think about a 75 cu. ft. cylinder would be fine. Don't get the little puny cylinders. Talk to someone wtih experience at the welding supply. Dave

Click to expand...

Dave,
I think the oxy cylinder I have is around 125 cu ft. (size M?). I can also get a couple of more for free that are slightly smaller, so if I've got a big project to do I can keep a 2nd one filled. The guy at the store said a "number 3" acetylene would be a good match size, which I think is about 190 cu ft.

122 is a common size for a medium O2 cylinder. They're often paired with a 75 acetylene. I'm not sure about the numbering system but if the acetylene is at least a 75 you should be good to go. Dave

Fair enough.

I bought some new tanks a few months ago to leave at a remote property I own in northern Michigan. I still have the price list here.

Type 75 CF Acetylene is 7" OD by 30 1/2" tall with the cap on. Cost me $125.

Type 40 CF Actylene is 6" OC by 21" tall with the cap on and $85.

Type 80 CF Ox tank is 6.7" OD by 37 1/2" tall with cap and $150.

Type 125 CF Ox tank is 7" OD by 46" tall with cap.

All come with one new valve, choice of male or female threads.

I don't know if those prices are good or not since I've never bought tanks new before. Here at home in NY I can't get my tanks filled if I own them. Exhange/lease only. I got looking for a used oxy-act set in Northern Michigan, complete and I couldn't find anything for less then $350. The ones priced at $350-$400 up were old and pretty beat up. So, I bought two new tanks for a total of $200 and a new torch set for $100 (hoses, regulators, blow-back valves, cutting and brazing), and figure I'm better off. I still had to pay to get the tanks filled though. I was little suprised that Acetylene tanks in northern Michigan tend to have male-thread valves, and here in NY female are used (at least at Air-Gas). When I got looking for a new torch kit, I didn't see any for sale that were meant for male-thread valve, so I guess if you buy them you need adapters?

Same boat as me, I've got propane around, basically no cost. Acetylene is expensive to rent or own the bottle and the refills aren't cheap.

I don't notice much increase in oxygen use from the preheat. If you cut plate days on end you could be fancy and get a cutting torch with the preheat shut off to save oxygen. For me, the mid size O2 bottle is the same price to rent as a monster bottle, and the refill is the same price, you're paying to get it put in the bottle rack. I do like being able to carry the mid bottles around though, easy to lift the cart up into the truck.

The little MC one originally made for motorcycles that used it for headlights

That is quite interesting!!!! I rebuild bikes as a hobby and would love to learn more!!! links??

(quoted from post at 13:25:20 11/30/10) Acetylene is the only fuel that can be used for welding because it is a neutral flame and won't change the properties of the steel. The draw rate is 1/7th the cylinder capacity per hour but it can be exceeded for short periods. If you want to heat with a rosebud, get a bigger cylinder. If the cylinder is near empty, also not a good idea to use with a rosebud. However, if your only heating up to say 3/8" steel, you don't need the biggest cylinder or the biggest rosebud. I think about a 75 cu. ft. cylinder would be fine. Don't get the little puny cylinders. Talk to someone wtih experience at the welding supply. Dave

Click to expand...

Went to the Welding Supply place on Thursday to get setup. Had 2 cylinders that were just laying around our shop. Saved me from having to spend $$$ on the cylinders. Exchanged them for filled M Oxygen and # 4 Acetylene.

When I told the guy at the welding supply (who told me that you couldn't just switch to a propane tip) that I had knowledgable people online tell me otherwise, he said "Let's ask Chris" who happened to be walking by and I assumed to be the manager. Chris said "Oh yeah, no problem, just put a propane tip on the torch". He DID say that there are some torch kits that you can't do that with, but the kit I was considering was multi-fuel (T-type hoses) and would be ok. I got the torch kit and am ready to make BIG fire. In fact, I hooked it up and tested it all on Saturday while the wife was shoveling the driveway from the winter storm that blasted us. I offered to clear the snow with the torch. She just rolled her eyes and said "boys and their toys". You know the old saying "If all you've got is a hammer, every problem looks like a nail". :lol: .

Anyway, thanks for all the advice and input.

I use a real oxy-acetylene torch for cutting and brazing. For bulk heating, nut removal a couple of different straight LP torches on the cheap with a 20lb BBQ tank.