Mini air tank

This is a useful little tool I made for another project. I use it to air up the wheelbarrow tire, bicycle tires and occasionally tease the dog with short bursts of air. I cleaned out my keyboard with it too. The best thing about it is its light weight; I've always hated lugging around the heavy big air bubbles that stores sell. I put in 100 psi because that is all my compressor will do; that is probably all anyone should put in it.

Supplies:

• 14 oz empty propane tank- Free
• Female air connector- $2
• Tire rubber valve stem $.75

Tools:

• ¼" NPT thread tap- $4
• 7/16 Drill bit
• Teflon tape
• Round file
• Drill
• Machine oil

First find an old 14oz propane tank that someone usually tosses on the ground at a popular local fishing or camping area. Hook up a gas stove or other propane attachment and empty the tank completely; this is important because many of these things are still half full when I find them. Drill a hole through the bottle valve with the 7/16 drill bit, then drill one opposite of the pressure release safety valve on the top of the bottle for the valve stem. Use lots of oil and patience to tap the threads inside the old valve, this is the hardest part. Use a round file to file out the other hole to the size needed for the rubber valve stem. Now wash the metal shavings out of the bottle well with dish soap and water. Shake out the water as much as possible and add a few drops of machine oil into the tank. Turn the female air connector into the new threads with some Teflon tape and press the rubber valve stem into the other hole. Air it up with a compressor or air pump and check for leaks. I had some metal shavings under the valve stem causing a leak, twisting the valve a few times fixed that. It doesn't hold much volume but its very useful for quick fill.

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