Propane vs aceteline and metal cutting

I saw the post by Dave2 about using his torch set up to weld with. didn't want to highjack his post, but did want to comment! Several yr's ago I bought one of Harbor Freight's portable band saws, and have used it extensively to fabricate metal with. I have a chop saw, but rarely use it, as blades don;t last long, and I have to watch out for sparks igniting old rags, that I never knew they were there. Grease rags are that way, they are not to be found when you need them, and right in harms way when you least expect it.The blades and repair parts for the porta-band's are redily available from HF. They are so cheap at HF, that if I needed another one,then I will just run to the store and pick up a new one. Milwalkie makes a deep cut porta band, but my HF porta band has lasted for 5 yrs, and has had a wheel replaced, once. I have been using propane for many yr's to weld, cut, and braze with. I seem to use more oxygen, with propane, and have had to use the 2 piece cutting tips, made for propane, but the local gas station will refill my bottle even on sundays. I suppose that they may have special welding tips for propane, simular to the cutting tips, but have never needed to ask. I just use a larger aceteline welding tip.Now oxygen is another story! It always runs out on the week ends, and NAPA wont exchange cyl's with me, due to the company that I bought the bottle at, isn't part of their group. Pacific welding, is closed on the weekends, and I have to wait till Monday to get oxygen. Luckily I don;t use my torch that much, but when I do need it, nothing else can replace it. Heat rusted bolts and nuts, heat king pins, to remove them, and just about would have my hands tied without it.

I couldn't operate without my torch set up. I saw one on craigs list about 2 mi from me. I bought it for 200.00, bottles about 2/3 full. I figure the gas almost paid for the unit. It is craftsman, but seams to be ok. I still like my victor unit. Stan

I know what you mean Ralph, I don't know how I ever got along without my torch.
I keep a half sized oxygen bottle as a spare. It's good insurance for weekends.
When I get the full size filled I go ahead and run the half size out,
have it refilled and put it back in the corner.

Propane is a real pain when it's windy. Propane is supposed to cost less than acetylene, but I never felt the need to investigate, because I didn't want the expense to change everything over to propane. Just an observation, but if propane were that much better, there would be a mass exodus from acetylene, which has just gone up in price again. Also, everybody's oxygen runs out on the weekend. That's why they have two cylinders. It's darn near imperative to have two acetylene cylinders; the stuff costs so much, you need to get the last pound out of it. You get no credit for a partially filled cylinder.

Welds made with propane will be more brittle. Has to do with the gas environment around the weld. They do make heating/rosebud tips for propane. Have never seen a specific welding tip, probably just because its usually not done. Propane doesn't tend to cut as well as acetylene. It is much harder to do things like removing bearings from a shaft with propane. If propane works well for you that is great. I do keep a couple of two piece tips around so I can use it if I need to.

Fritz,

To light propane turn on some oxy with
the propane and it will lite as good as acet.
Propane does cut a little better than acet,
and is cheaper to use , why do you think the
junk yards and scrap yards use it . Many use
a large propane (100 gallon) and large liquid
oxy , and cut for weeks on it .
Propane will braze and solder ,but does not
weld. Been using propane for 40 years ,mostly
to cut ,but also to heat. Rosebud for propane
has slightly larger holes in it,have a # 12
for each gas.
Also bought a cylinder of magna gas ,it's
hotter than propane ,but not as hot as acet.
It will weld cast iron , I bought it when the
acetylene plant burned as a substitute .

george

Fritz,

To light propane turn on some oxy with
the propane and it will lite as good as acet.
Propane does cut a little better than acet,
and is cheaper to use , why do you think the
junk yards and scrap yards use it . Many use
a large propane (100 gallon) and large liquid
oxy , and cut for weeks on it .
Propane will braze and solder ,but does not
weld. Been using propane for 40 years ,mostly
to cut ,but also to heat. Rosebud for propane
has slightly larger holes in it,have a # 12
for each gas.
Also bought a cylinder of magna gas ,it's
hotter than propane ,but not as hot as acet.
It will weld cast iron , I bought it when the
acetylene plant burned as a substitute .

george

I have a couple of small ownership oxy tanks that no one will fill. I rent a big tank and fill my small ones with a pigtail.

This topic should have been in tool talk but none the less, propane doesn't use a neutral flame which provides the proper atmosphere for fusion welding. On steel under about 2" acetylene will give the best and fastest cut using the proper size tip. On thicker steel propane has an advantage because it has more BTU's in the secondary flame which helps to preheat the steel ahead of the cut. Acetylene has way more BTU's in the primary flame and a higher flame temperature.

Another trick to light propane is to put the tip on the metal at an angle and then light it. Propane is cheaper to buy than acetylene but uses about a 3 to 1 ratio with oxygen compared to close to 1 to 1 with acetylene, which means the savings aren't as great as originally thought. I prefer acetylene for several reasons. One of the biggest is that it's easy to clean the tips and you can see a little better because the tips are narrower. The 2 piece tips are a pain to clean. You have to take them apart every time. I've used just about every kind of gas for cutting and acetylene gives the nicest cut. If you have lots of heating to do with a very large rosebud, propane makes more sense because you don't have to worry too much about withdrawing it too fast. Acetylene you have manifold 2 or more cylinders together. I'd guess Magna gas is a kind of methyl acetylene but still wouldn't use a neutral flame. I don't think there is a substitute for acetylene when it comes to fusion welding.

Only uses more oxygen for the heating which is small compared to cutting. Depends what you're using it for.