to this day i have yet to find an adhesive that works on polyethylene and polypropylene. epoxy doesn't stick at all, nor does CA clue. just about everything in the store says or "does not bond polyethylene or polypropylene" does anybody know of any adhesives that work on these plastics? thanks, meat...

I know you've already considered this singularity, but im curious to think what other people think - do you guys think the fan from the bottom of an rc hovercraft, the one that lifts it off the ground, that forces air under the craft by sentrifugal force, do you guys think that has enough flow to ve...

i wouldn't use one of these unless i did some experimentation or somebody else did to see what pressures they fail at with different diameters and how long they last and stuff. my gut feeling is that this wouldn't be safe but i honestly dont know.

thats right jimmy. by default, any pressure rated fitting will be able to stand up to the pressure of a drain pipe.

First of all, do some research, the answers to all of these questions are in the forums, the spud wiki, even try google searches. To build a simple pneumatic, with a sprinkler valve, is probably around thirty dollars, less if you have pvc cement and primer (which is essential, you must use primer) a...

would it be possible to use two of the cheaper lower flow regs to give satisfactory flow? what if you bought one, and if it doesn't have good enough flow, add another one?

also, another difference is that for me it says You're member of SpudFiles, whereas for you it says You're administrator of SpudFiles
I've never seen that before.

singularity please dont try that gun above 100 psi. From participating in its construction, i know that the 1 1/4" male adapter and coupler were put together using a 1" coupler instead of a piece of 1 1/4" pipe. The 1" coupler was not a snug fit, with a millimeter or two of wiggle room around it. th...

one easy solution would be to use a sprinkler valve, although it looks like you want a piston, and i'm sure you've considered a sprinkler valve already. basically, just do some research, figure out your design, and build it. at that small of a size it wouldn't be too expensive to mess up a couple ti...

would you care to elaborate on that plan? now im curious...

try McMaster for the valve, I've also heard some Walmarts have them with the auto parts, but I've never seen them in stores. what i do is i epoxy the schraeder from a bike inner tube into a brass 1/8 x 1/4 bushing and use that. and sorry, i dont know much about copper.

yeah if the pipe itself says something like NOT FOR PRESSURE on it that means you should not use it for pressure. if it is pressure rated the pipe will say NSF-pw and have a pressure printed on it in PSI. i would agree, start over and use a piston valve and pressure rated pipe and fittings, its wort...

you want it to make good sealing contact so it dosn't leak, which is easier with a more pointed edge, but you want to avoid cutting through the sealing face. so i would change that analysis slightly:

> - bad

] - fine, but not the best. can work fine.

) - ideal

a piston valve would be your best bet here. a ball valve is better than a sprinkler valve becuae of the value of high flow over fast opening with the long barrel. a piston valve combines these benefits and can be triggered with a small ball valve or a sprinkler valve. this would open fast and the fl...

or ideally you could use a secondary diaphragm valve, a sprinkler valve would be great, to actuate the main valve. this in turn could be actuated with a blowgun. or you could just use a ball valve.