Homemade pump: more user friendly with innertubes
Tennsteven gave me some ideas about handling Scrotal ache after starting to pump, and so I’ve done some experimenting myself with modifying an aquarium gravel tube for pumping. I should mention that I’m using a MityVac attached to a 2" Python gravel tube.
(1) I got the smallest motorcycle inner tube I could find (~2.5" diameter; a Harley dealer gave me a used one), so it’s diameter is larger than the inner diameter of my pump tube. I took some 1/8" nylon cord and cut just enough to create a loop that’s slightly less in circumference to the pump tube. Melting the ends together creates a continuous, unbroken loop of nylon cord. Then I cut a 4" length of inner tube, and doubled it over on itself with the loop of nylon cord inserted in the circumference of the fold itself. This whole arrangement can slide snuggly over the outside of the pump tube, creating a sleeve-gasket arrangement, with the fold itself being held just within the circumference of the pump tube because of the nylon cord thats hidden within the folded-ove inner tube. It makes the edge of the pump tube much softer.
(2) I also bought the largest bicycle innertube (~2.125" diameter) I could find, and cut a two inch length off of it. After inserting one inch of the bicycle innertube into the pump tube, the remaining one inch is turned inside-out over the outside of the pumptube. It slighlty softens the edge of the tube, and creates a better vacuum. I’ve tried using arrangement #1 and arrangement #2 together and separately.
(3) I also used a 9" length of the bicycle inner tube as a variation of "condom pumping." It was attached to the mouth of the tube by turning an inch of innertube inside out over the outside of the pump tube (like #2 above). I was able to comfortably go up to 10" Hg (usually I can only handle 5" Hg at this point). But I’m not sure of the advantages since an inner tube won’t expand as readily as a condom, nor is the end closed off like a condom… so you still have more pressure being put on the glans. Attempts to clamp off the inner tube have been unsuccessful so far. There might be some application for increasing glans size using such a sleeve inside a pump tube… kind of like the "mushroom" pumps that LA pump sells at an exorbitant rate.
When I’ve experimented a bit more with inner tubes in the pump tube, maybe I’ll post some pics of the equipment modifications. But if what I’ve described makes sense to anyone, they may want to try some similiar modifications.