There's nothing wrong with that line of thought - it should work just fine. I could never get it to work personally though. :wink: That being said, my lack of tools hinders every one of my projects and could contribute to an ignition failure somewhere in there. Try out the ignition setup for yoursel...

The reason I made my own spark plugs is because I couldn't find any that were NPT threaded. However, I also didn't look very hard for one. If you do find one, you shouldn't need to insulate it; the ceramic built into the spark plug will definitely be enough. There is no reason to put effort into ins...

It should work, although make sure the barb itself is wide enough to fit the wire though with room for some epoxy as well. If the wire isn't well insulated well, the spark won't jump where you want it to.

There are good ways to do hybrid ignition and bad ways. I've always used a pretty ghetto but effective schrader valve spark plug of sorts. It's kind of a sloppy, bad way to do it but your idea sounds even worse! (no offense :D ) The picture up there is the inside view of the spark plug. I got a 1/8"...

Shouldn't matter really. I've used galvanized personally but that's because there's a wider variety of galvanized fittings than black iron at my local hardware store. Just avoid plastics ad you'll be fine.

Well, you want your piston to be a very close fit with the walls of the pipe it's traveling in. It should also be able to slide back and forth without much resistance. The rule of thumb for piston travel is that it should travel about 1/4 the length of the valve port. If you're shooting golf balls, ...

The only shock pump I've owned would just connect to a schrader valve. They're generally threaded to screw onto the schrader so that the pump won't pop off when subjected to the relativity high pressure. As for blowguns, they seem to be hit or miss. I've had better luck with Tru Flate blowguns like ...

I'm 21 guys! And I've been hanging around Spudfiles since I was wee little 12 year old lying about my age in order to register
Thanks for the good times everyone.

The problem with a backpack full of air is that it won't liquefy unless it's a nice chilly 77K outside.
This isn't the case for propane, which will continue to evaporate in the tank as it is being extracted.

If only propane didn't smell like butt...

I'd just build it and see what happens. At worst, you'll have made yourself a little plinker/measuring stick for future projects. With a combustion, you can just reuse the igniter when you want to scale up, so you'll have spent like $10 on PVC.

Reminded me of this list I saw a while ago on facebook

Most of them either have a keychain type ring and/or a hole that the ring passes through. I'm sure you can rig up a trigger system that simply pulls the valve open. Taking a couple steps down in technology, you can always pull the ring with your finger.

I remember Luckythirteen doing it on Spudtech way back in the day; I hadn't seen D_Hall's until now! Boomer58cal, that last picture looks good! I'm sure the fourth sprinkler really does help with piloting three others. That task would be a bit much for just a blowgun, I'm glad it's working out for y...

Whyyyyyyyyyyyyyy would you do this?!

Hate to break it to you, but it's been done! I tried searching for it for a good 20 minutes and came up short, but oh well.
You could always kick it up a notch and pilot the pilot with another sprinkler