I need around 10-15 gallons, (over 35,000 milliliters), of volume, rated to up to at least 50 PSI, which can hold both air AND water.
The simplest way I could think of to do this would be to modify a small 10 gallon carry tank. There are several reasons for this:
1.) Simple, conventional hook-up. Have a 1/2" NPT tank fitting welded to the tank, making it easy to connect my "various hardware" and prepare the tank for water operation.
2.) Specialized tanks are expensive. A carry tanks runs anywhere from 20-30 bucks, and can "easily", (hopefully), be modified to hold water and air.
Here's my problem. The tanks are steel. Pretty corrosion resistant when used with normal air and drained periodically, but not good if I want to be pumping water into one.
My two ideas for solving this problem are outlined below. Please don't post suggestions telling me to "jusst git a stanless tank ther beter!". If you have another idea to water-proof the inside of a standard steel carry tank, post em below.
Idea one is to install a rubber bladder. The material would probably be nitrile rubber sheet about 1/32-1/16" thick, and glued together with rubber cement. The procedure I have to install it is straightforward. Push it through the 1/2" threaded hole until it touches the bottom, lay some plastic over the threads in the tank fitting, lube the hole up, and inject compressed air into the bladder to expand to the size of the tank. Some epoxy or other glue could be used on the outside of the bladder as well to make sure it stays in place. After this, all the installation parts will be removed, and the rubber can be cut to a "spout", which will be glued into whatever fitting I use to connect to my "hardware".
I really like the above idea. It's simple and it should last as long or longer than the rating already imposed on the tank.
The second idea is to spray in some sort of lining. This would have to be done with a rather liquid application process, and I really don't like it. There's too much a chance the lining will miss a spot, allowing rust.
Any other ideas? Right now my money's on the bladder design. I would also have to inspect the tank periodically, because the bladder may "sweat" as cold water is pumped into it. Our water is pumped from a well, so it is both high-pressure and cold, (100 PSIG and around 50-60 degrees in the summer).
Also, this actually does pertain directly to spudguns. Some older members probably know what I'm building, but nobody else ask, because I hate giving stuff away.
