Yafmot Posted November 17, 2009 Share Posted November 17, 2009 After a while, you get tired of potato juice & fragments squirting out every time you load up a tuber in your shiny, magnificent $9.00 spud launcher. You start thinking of ways to push other stuff out of it. That's what happened to me, so I started thinking about gas checks in shotgun shells, particularly the little discs they put behind slugs. Fear not, root shooters, for a cheap method of launching just about anything that will fit down the bore is at hand. ABS (Acrylonitrile-Butadiene-Styrene) pipe is too rough on the inside. Same with PVC, to a lesser extent. So if you're shooting a 1 1/2" bore hardware store special, you'll probably have to do a little looking around for some like-sized clear acrylic tubing. Take about 18" of it and put several generous coats of PVA (Polyvinyl Alcojol) mold release inside it. Then mix up a small, quick batch of two part polyurethane foam and pour it down the upended tube before it kicks. Depending on the formulation & cure time, you may have to stick it in an oven or hit it with a hair dryer. You should only heat it up enough to accelerate the foam, since it doesn't take much to distort the acrylic tube. After a couple of hours (maybe less, depending on your foam) you can use a broomstick or whatever to drive out a "loaf" of foam from the tube. Then you just cut it up into 1 1/2" lengths and there you go! Now you can shoot anything! Arrows, golf balls, the torso from your niece's Barbie doll, whatever! I know from firsthand observation that it will propel a graphite shaft, brodhead arrow a good 8 inches into the trunk of a 50 foot Sawtooth Palm from 40 feet away. And it'll send a golf ball on a suborbital trajectory. And that's just with MAPP gas! Just think of what it might do with an OA mix! There are things you can do to make the seals reusable. A simple circle of woven fiberglass tape stuck on the back side will keep the hot gases from attacking the foam. Trust me, you're gonna' love this shit! Link to comment Share on other sites More sharing options...
FrankRizzo Posted November 21, 2009 Share Posted November 21, 2009 OA mixes should **never** be used in a plastic spud gun. The mixture can and does dentonate within a narrow range of mixtures. If you're unlucky enough to find that *magic* mix, the detonation shockwave will destroy the gun in your hands. It's not pretty when it happens. Link to comment Share on other sites More sharing options...
Yafmot Posted December 25, 2009 Author Share Posted December 25, 2009 Firing from the hip, I once took out a magpie atop a 60 foot cedar tree about 50 yards away. Big poof of feathers. Think we were using MAPP gas. Nice. Link to comment Share on other sites More sharing options...
psyco_1322 Posted December 27, 2009 Share Posted December 27, 2009 ^ AHAHAHA... I would pay for a video of a magpie being shot with a spud cannon. Link to comment Share on other sites More sharing options...
NightHawkInLight Posted January 4, 2010 Share Posted January 4, 2010 OA mixes should **never** be used in a plastic spud gun. The mixture can and does dentonate within a narrow range of mixtures. If you're unlucky enough to find that *magic* mix, the detonation shockwave will destroy the gun in your hands. It's not pretty when it happens. Or a metal gun for that matter. And it doesn't necessarily take a magic mixture, acetylene on its own without oxygen to fuel it can become unstable and explosively decompose. A spike in pressure caused by combustion further down the chamber is certainly more than the stable limits of acetylene (~15-20psi). Not a bad idea for sabots though. Link to comment Share on other sites More sharing options...
FrankRizzo Posted January 4, 2010 Share Posted January 4, 2010 NightHawk, you are absolutely right; acetylene is a no-no. Link to comment Share on other sites More sharing options...
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