I will need:
- 1/8 in id brass pipe
1 small screw
1 small nail
8mm ID pipe
- Make a piston from hot glue inside the brass pipe.
Assemble a piece of rubber onto the piston and apply the screw.
Glue a nail inside the pen cap.
Glue the shrader valve into the brass pipe.
Grease the piston and slide it down the brass tube.
Glue the pipe into the brass tube 1/2 an inch away from the piston.