A little while ago I bought a 5 gallon air tank for $5 at a yard sale. The old Schrader valve manifold was dead so I made a new one for $15 worth of parts from Harbor Freight.
It is easily filled using a 1/4 inch connector from another air compressor. The 1/4 inch female connector allows me to attach another air hose to connect a tire inflator or blower.
It is great for daisy chaining to an 8 gallon air compressor and making a 13 gallon compressor.
Recently a coworker was cleaning out his garage and gave me a 10 gallon air tank with a dead Schrader valve. Another $15 in Harbor Freight parts and it’s been improved too.
Here are pictures:
What you need is a 1/2 to 1/4 inch NPT adapter, two 1/4 inch T-connectors, a 1/4 inch ball valve, 1/4 inch male and 1/4 inch female air hose connector.
One thing I use it for frequently is using this instead of canned air. I’ll fill the 5 gallon one up and hook a short hose with blower nozzle on it and let the wife use it to clean her sewing machine. Given the price of canned air, this paid for itself quickly.
Works like a charm.
If you come across an air tank like this at a yard sale on the cheap (I’ve seen a few), this is a worthwhile modification.
Have you checked inside for rust from condensate?
Only downside is that if you bump the valve you lose all your air. I would use two females and then use a male/male adaptor with a ball valve when I needed to fill it or connect it to another tank.
It’s not been a problem for me and this way I don’t have to worry about an adapter to lose.
I used to use R12 bottles for that, no idea if the R134 tanks will work. That does tell on my age, doesn’t it?