2" ID ABS pipe for the tank body
¾" PVC pipe for the center post
1 ¼" PVC pipe for the film spool
2" ID ABS type pipe cap.
2" Rubber cap to fit the pipe (bottom cap).
Two ¾" PVC pipe caps for center post
¾" ABS pipe for filler neck
1/16" thick black plastic sheet for light baffle
0.092" trimmer line (about 3 feet. This is what was handy.)
No. 3 rubber stopper.
All purpose PVC Cement
#2-56X1/4" stainless steel screw
(Note: All material was obtained at my local Lowe's Building Center except the rubber stopper, 2-56 screw and super glue from ACE Hardware).
This is the second version of a PVC tank. I tried to correct the problems I found while constructing the first model.
CUTTING THE PIECES:
I started with a 4" long piece of 2" inside diameter, black, ABS type PVC sewer pipe. Next was a disc of black plastic sheet cut to 2 3/8" diameter to fit under the cap at the end of the 2" pipe. The wall thickness of the 2" ABS pipe is 3/16", so I cut ¼" off four sides of the 2 3/8" disc to make a passage for liquid into and out of the tank. An alternate method would be to cut a 1 7/8" square of plastic sheet, then trim the corners to fit the inside of the 2" pipe cap.
I drilled, then filed a hole in the center of the ABS pipe cap to receive the filler neck. The ¾" ABS pipe was cut to a length of about 1".
For the center post, I cut a piece of the ¾" PVC 3" long.
Next, using a belt sander, I flattened four sides of the ¾" pipe caps, and flattened the end of one to allow cementing it to the light baffle. The square end caps will hold the spool straight while still allowing the liquid to drain.
For the spool, I cut the 1 ¼" pipe to a length of 3 ¾", then using a #41 drill bit (0.096"), I drilled holes every ¼" around both ends of the spool to allow fluids to drain. I inserted one end of a length of 0.092" diameter weed trimmer line into a hole and wrapped the line around the spool allowing 7/16" between the wraps. This allowed a little over 6 turns and will hold a strip of film of 76 cm maximum. The trimmer line was secured using "super glue". I found a product called "SureHold Plastic Surgery" which will cement all types of plastic, including nylon. I glued the ends of the line where it goes into the holes in the spool and put a dab of glue every half-turn to hold the line in place.
I added a #2-56 stainless steel screw to hook the hole in the end of the Minox film to the spool. The spool is shown with a 30-exposure length of film in place.
The finished tank requires about 110 ml of liquid to fill above the light baffle.