Air compressor repair/upgrade

[skyhook]

Propane tanks are plenty strong for compressed air. I use a 20# tank as a portable air tank. According to Wikipedia propane pressure is 177 psi at 100F. The tanks would have to be rated at several times that. You'd have to make a provision to drain the condensation out.

Not really, you just keep the tank on it's "top safety ring" as I do.
Disconnect the line and the water flows out. I use the 100 lb tank as a secondary holding tank.

 

[BHD]

I have brazed a few tanks, when I started out,

IT IS A DUMB THING TO DO

on most tanks there is oil in them heated oil vaporizes, and creates a gas, unless one has purged the tank or filled with water, (and you cant braze a tank with water as the water will cool the steel faster than you can heat it), If it explodes the tank will be the least of your worries, if you survive,

also you know the quality of the tank is compromised, and if the shell does let go you talking about the possibility of injury and death,

Look at some of the pictures below.

https://www.google.com/search?newwi....0.-fCRSdAuhXo&q=air compressor tank failures

 

[SandburRanch]

Domestic water heaters are required to have a 150lb. working pressure rating. Check with a few plumbing supplies to locate a nearly new salvage tank that has malfunctioned for a salvage price. Hydro test before going to the trouble of stripping skin and insulation etc. They also work excellent as a sediment tank for water wells and mine has been in well service for nearly 30 years.

 

[bigdeano]

Using the tank upside down would work fine. If I wanted to put a fitting in the bottom I'd just drill and tap a pipe thread in the bottom. No need to weld or braze anything. Tap it just deep enough so the male fitting screws in just the thickness of the metal, so it's not sticking up inside.