I have been a lurker here now for quite some time. This forum is great and I have added much to my knowledge. That being said, I have been making sausage and smoking meats and fish now over 35 years. My equipment has been a mix of mostly odds and ends and some homemade devices. It worked, but not all that well. I was intrigued recently when I saw both a commercial and homemade water powered sausage stuffer on the internet. Being a handy kind of guy I decided to build one. Here is my story.
-The most difficult part to make is the piston. Others have used thick plastic cutting boards and thick sheet plastic but I went another direction using a 3" pvc glue cap. The tube itself is a 4" pvc drain pipe. Mine is 30" long and will hold about 15# of sausage.
-The 3" glue cap will fit nicely inside of the 4" pipe. I chose to turn the cap diameter down (I used a wood lathe) a little bit but I bet you could use it right out of the box. Two grooves with square bottom corners need to be cut. Again here I used my wood lathe and a faceplate jig to hold the cap concentric. I think you might be able to do this with a table saw also it you were careful and went slow.
I purchased the "O" rings off the internet. Cut these two grooves carefully for depth so the "O" rings seal inside the 4". If you cut too deep the piston will not seal and water will pass through.
-The top of the stuffer is another area that requires a little work. I glued on a 4" pvc threaded adapter. I also then purchased a 4" threaded plug. The plug needs to have a hole drilled into to accept the drainpipe adapter commonly called a desanco fitting. I used a 1 7/8" hole saw or Forstner bit for this. I must be a snug fit so the desanko can be glued in.
-Now you must glue another 4" glue cap to the oposite end. This is for water in and water out. Drill & tap two holes for a 3/4" pipe fittings. I did not have a 3/4" pipe tap so I made one by using a 3/4" galvanized pipe nipple. Just make 4 cuts around its perimeter with an abrasive cut-off blade and this will work for the soft pvc plastic. Be sure to tap this square and straight. I purchased inexpensive plastic garden hose on/off valves for this.
-When you are ready, grease up the piston with some shortening like Crisco, assemble your in and out garden hose and fill the tube with your prepared sausage blend. I purchased a Lem sausage tube for snack sticks and also have other sized in plastic.
-Bleed the air our of your stuffer first by running water in and have the exit port open. Close all valves and put your casings unto the stuffer tube. Turn your garden hose on just a little where it is connected at the house. If opened up this thing moved way too fast. Now just crack open the plastic valve on your tube and start filling the casings. Here is a tip...when you need to stop, first open the drain valve and then close the inlet. This prevents the residual pressure from pushing more meat out the tube. Parts for this stuffer run $30-40.