Gas Tanks - Oxygen and Propane

Oxygen Tank - Usually rented at your local welding shop. Tank size can vary between 20 cubic feet of oxygen to about 300 cubic feet of oxygen. The larger the tank, the cheaper the price is per cubic foot. Prices can vary a lot depending on location and store and are usually negotiable. Shop around. I have seen prices for large tanks under $10 to over $40. We pay $21. Each time you refill, you will pay this fee (actually exhanging tanks, not using the same one). There is also a monthly rental fee for each tank, usually between $3 and $5 and may require a deposit for it, around $100. You can bring the tank to the welding shop for exchange or have the welding shop deliver it to you, for a fee of course. Don't forget to find out what this fee is when you are shopping around. Some will not deliver to certain areas like residential neighborhoods. Ask them. Also consider how heavy the tank will be if you have to move it yourself or up a stairs.

How about buying your tank instead of paying a monthly rental fee? Sure! The "break even" point may be 3 years. Run the numbers.

How long does the tank last? It depends on the torch and is the torch setting high or low. Typically a Minor Burner Torch set at a medium setting will use about 15 cubic feet of oxygen per hour or approx $1 per hour.

We have been talking about a compressed gas tank. There is also another type of oxygen available, Liquid Oxygen. When Oxygen is cooled it turns from a gas into a liquid. You can use a tank of Liquid Oxygen. It will last a long time and would cost much less to run your torch. Cost of a 160 Liter tank is about $100 to $200. Also a $1.50 to $2 per DAY rental fee. We pay $45 per month. Once again, shop around.

Liquid compared to Compressed Tanks of Oxygen

Advantages of Liquid	Disadvanatages of Liquid
2 to 3 times less expensive than compressed	Large heavy tank needs to be delivered. Neighbors may get upset seeing a "scarry" looking tank being delivered to you.
	May not be available in all areas
	Some suppliers do not want to sell and deliver to residences or homes, only businesses.
	Within hours or a day of using the tank, the oxygen leaks, bleeds off all the time until you begin to use it again. Remember the liquid is warming and turning to a gas and it needs to go somewhere. You must use the tank often, almost daily to take advantage of the cheaper price.

Propane Tank - Simply use a standard 5 gallon (or larger) Barbecue Propane Tank that can be purchased at your local hardware store. Costco has a good price but sells only in the BBQ season.

14.1 Ounce Disposable Cylinder	19,000 BTU's
16.4 Ounce Disposable Cylinder	22,000 BTU's
7 Pound Refillable Cylinder	150,000 BTU's

The BTU's of a torch can vary a lot a lot depending if the flame setting is low or high.

Propelyne Gas

Another option is to use Propelyne Fuel which is a little hotter than propane.

Propelyne Fuel is also called Brazing Fuel or a common brand name is MAPP Gas.

You can purchase Propelyne two ways:

1. Disposable Cylinders - Around $9. You can usually find them at your local hardware store.
2. Refillable Cylinders - Sometimes difficult to find. Check with your local welding shops. Air Gas, a large supplier of, welding supplies, sells Propelyne in 3 sizes:

Size of Tank	Who Owns Tank	Daily Rental Fee	Refill Charge
7-1/2 LB	Tank ownership	none	$22.50
30 LB	Rental	27 cents	$32.76
60 LB	Rental	27 cents	$109.50

Natural Gas

Most torches work with natural Gas. Cost of the gas is about the same.

Advantages of Natural	Disadvanatages of Natural
More convenient, you do not have to refill tanks.	Propane has a hotter flame than natural gas. This is the big reason not to use natural gas unless you have to.
You never run out of gas.	May require a plumber to make the gas outlet near your work area, where the propane setup is easily moveable.
You don't need a Propane Regulator	Nature Gas pressure is not adjustable. You are stuck with the barely minimum pressure available.