Cutting Torch Question

[Eric_Phillips]

Brian,
I just want to clarify your technique when using propane. Are you saying the hotter part of the flame is about 1 inch past the inner cone when measuring from the tip?

 

[xlr82v2]

Brian,
I just want to clarify your technique when using propane. Are you saying the hotter part of the flame is about 1 inch past the inner cone when measuring from the tip?

Eric,

Yes. OK... maybe not technically the "hottest" part of the flame... but where the most "heat" is.

Here's a webpage that I found that talks a little bit about it.

I also took a couple of pics of my torch and added some labels to show what I'm talking about... The pics aren't the best, since I couldn't get the camera's light metering mechanism to cooperate and get a good detailed image of the flame. I shot 1 pic through my welding goggles, it is a little better. But, I think this illustrates what I'm trying to explain...






If you take your oxy-propane torch, and preheat with the flame tips on the edge of your workpiece, you'll see that it is fairly slow to heat up to cutting temperature. But if you raise your torch so that the edge of your workpiece is in about the middle of the "zone" in the picture, you'll see that it comes up to temp very quickly. The drawback with propane is that the heat is not as "focused" as it is with acetylene. But, it still works quite well. Like I said earlier, it's just "different".

 

[Eric_Phillips]

Brian,
Thanks for the reply. I aquired a stick welder and have some projects I would like to do but I keep running into the cutting issue. After reading this thread it sounds like propane would be a better option than acetylene for me.

 

[slowzuki]

I went propane when I bought my own outfit. Its safer, way cheaper, and not that much worse for getting started. It cuts just about the same once started. The same rules apply, clean tip equals clean cut.

My plasma is nice too but you can't use a plasma to hack old dirty stuff apart. It will ruin your torch and tips quicker than anything.

 

[Rara Avis]

Thanks for the replies - Is there a pressure at which propane is dangerous?

When the LIQUID IN THE TANK is 110 degrees F, the pressure in the tank will be about 200 psig. When the liquid is 60 F the pressure is 90 psig. When the liquid is 0 degrees, you get about 20 psi and when the liquid is about 40 degrees below zero, you will get NO pressure.

Gas Facts : Infomation about fuel gases


Like propylene, most propane tips are of a two piece design. Propane often gets unfair criticism because it really needs changing your torch (from an equal pressure torch to an injector torch) and not just changing your tip to get the best performance. Most torches are equal pressure and designed for gases such as acetylene which are lighter than oxygen. Propane is a great deal heavier and runs much better through a low-pressure injector torch with a setting from a few ounces to about two pounds per square inch when cutting.

 

[KYErik]

Brian,
Thanks for the reply. I aquired a stick welder and have some projects I would like to do but I keep running into the cutting issue. After reading this thread it sounds like propane would be a better option than acetylene for me.

I used my stick welder as a torch for a year before I finally broke down and bought a real torch. It takes lots of 6011 rods on the 200 amp setting to burn a rough 1 inch hole in a 1" thick by 2 inch wide steel bar...

I like the torch much better- much faster and neater. I was considering propane as well, but I went ahead with acetylene because I got a good deal on an acetylene tank and I didn't want to spend more to convert to the special propane hose and tip.

I have heard the propane folks say that the slag after a cut is easier to knock off.

 

[xlr82v2]

... I was considering propane as well, but I went ahead with acetylene because I got a good deal on an acetylene tank and I didn't want to spend more to convert to the special propane hose and tip.

I have heard the propane folks say that the slag after a cut is easier to knock off.

Erik,

I'm sorry to hear that... Just kidding!!!


Did you lease your Acetylene bottle or did you buy your own, and what size did you get? How good of a deal was it, if I can be nosy?

 

[KYErik]

Erik,

I'm sorry to hear that... Just kidding!!!


Did you lease your Acetylene bottle or did you buy your own, and what size did you get? How good of a deal was it, if I can be nosy?

The deal? Well- it looks as if they will be free- so that's the best kind of deal. I got the large size acetylene and oxygen cylinders.

The acetylene tank is about 4 feet high and as big around as a basketball. The oxygen tank is about 5.5 feet high and as big around as a basketball.

Its a long story though.

About 25 years ago, my dad (a farmer) paid for a lifetime lease on a set of O/A cylinders from a regional welding gas supplier. He got the lease/tanks at a local "mom and pop" radiator shop. The radiator shop had some sort of an agreement with the gas company that refills the cylinders (exchange system) that it would be the county distribution point for that company. Well, there was some sort of falling out between the rad shop and the original gas company and some way or another, another gas company got an agreement with the rad shop owner to let him distribute their welding gas.

The rad shop owner asked the new gas company about his lifetime lease customers (with the old gas company) who depended on him for refills. So the new gas company says they cannot fill the old company's cylinders (they are stamped with company name) but they will lease a new set of cylinders to all the "old" customers for a discounted rate. The rate was supposed to be $60 per tank for a 5 year lease. So my dad went ahead and filled out all the paperwork for the new set of tanks (name address phone number etc.). He was supposed to be billed for the lease through the mail by the gas company, but had to pay for the gas on the spot. He told the owner that I was looking to lease a set of tanks and the owner said I could sign up for the same deal. I filled out the same gas company paperwork and the same thing happened, I paid for the gas up front and was told to wait for the $120 bill from the gas company for the pair of 5 year tank leases.

That was 3 years ago and my dad and I are still waiting for our lease bills from the lease company.

My dad said that the rad shop owner made a few cryptic remarks that made him wonder if we'd get a bill at all. Maybe the new gas company said they would give the tanks away to old customers but the rad shop owner wasn't allowed to advertise that or say it outright.

I need to exchange my tanks in the next 4-5 months (getting pretty low) so I suppose I'll see if there is an issue then.

 

[yomax4]

Victor Torches are Any Fuel Anytime, Just change the cutting tip to match the fuel gas ie: Propylene, MAPP, Propane, Chemolene or Acetylene. Acetylene has been the Industry Standard for Many years. The Others, Called Alternate Fuels, Are Much Less to use in the long run and much safer as far as Flash Backs are Concerned. Personally< I grab the Plasma Cutter and Cut Safe.. ( Im a Salesman for Victor, Thermal Dynamics , More).
Go to Thermadyne.com and you can get Tip Charts and any other info you need, Cant find it there? Send me a note and I will send you what you need.

Good Luck..