(also fits discarded standard bathroom tissue & paper towell tubes. Free tubes to make smoke cans, 2" mines, exploding targets & cannister aerial shells) Simply plug bottom of tube with a disc cut from a cerael box or similar, using the tube as a pattern and cutting disk inside the drawn line. A drawing compass is a great way to draw perfectly round discs. Use a length of PVC pipe (or similar) that fits the inside of the tube to push the discs in. Apply glue (PVOH) inside and out, allow to dry and glue another disk in the bottom. Use plenty of glue. If making aerial shells or mines, punch a 1/4" hole in several discs glued together and glue the time fuse in place. Push it in place from the top to the bottom of tube using the PVC pipe. Glue in place and allow to dry. Add enough glue inside around fuse 3/8" thick and allow to dry upright (with fuse in a hole on the workbench). This step will reinforce the bottom to withstand the lift charge shock. Note; Before filling with composition, brush the inside of tube (with bottom discs glued in place) with Firefox Fire Retardant to discourage burning fallout or smoke can burnthrough. Discs can also be treated. Moisten with wheat paste and wrap 6 1/2" wide strip of kraft paper bag around tube (parallel). This leaves enough overlap to paste over end discs to close. Do so over the bottom disc, with or without time fuse, depending on application and glue the end cap on. Fill the tube with appropriate composition(s) or garnitures and close in the same manner. Apply more paste to outside and wrap on more kraft paper folding over the ends as before. The number of paper laps is just enough to effect a proper fit in the mortar tube. It should have 1/8" clearance on each side (1/4" total) for proper fit in mortar. They are fired from a 2" ID mortar. Smoke cans; Fuse can be added to the top end for smoke devices. Press moist smoke comp in place leaving a tapered core in the center to increase surface area of burn / smoke volume. Place a ring of glue around inside of tube and push a double disc punched with a 1/2" center hole in place leaving approx 1" of empty space from composition. Glue and dry. Fold paper strips over the edge and inside tube against discs to reinforce against pressure. Secure fuse in place with prime slurry and place an end cap over to finish. This cap is not glued in place and removed for use.