New to hybrids

[Juggernaut12121]

I know I must be pretty annoying since I only come on here to ask stupid questions... But stupid question time!
I was looking into building my first hybrid and upon studying I encountered a problem with the materials. I saw all sorts of people using what looked like sections of galvanized pipe (and sometimes black iron pipe), but at my local hardware store I can only find galvanized and black iron pipe with seams down the middle, and I thought that that stuff was only rated to 150 PSI. I also looked into some pictures and it looked like the pipe wasn't seamless. Sorry about my outstanding stupidity and noobishness in this area but I'd much appreciate some help

[MrCrowley]

That's the same stuff most of us use. I believe the WP rating of 150PSI is more for the threads/seals as these fittings can be a bit difficult to seal at high pressures (at least in my experience). Either that, or the main use of these fittings is for jobs where working pressure is below 150PSI. Probably not much point trying to get your material to be rated for high pressure when it only needs to handle 150PSI.

I'm not sure of the reason why the rating is only 150PSI but you can definitely take it higher. 10X mixes in hybrids should be fine for handheld.

[Juggernaut12121]

Thank you! I have another question if you don't mind, is black iron or galvanized better to use?

[noname]

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.

[mobile chernobyl]

Galvanized [probably] won't rust as fast - which in environments like a combustion chamber - tends to happen very fast (oxidation). I'd recommend it just based on that fact and having the safety of mind if you leave it in your garage over a year then want to shoot it again without having to worry about taking it apart and inspecting it - even though oxidation through a ~5mm steel wall doesn't usually happen that fast naturally lol.

[Juggernaut12121]

Thank you for all the help! Once again I wouldn't mind some input on another question; for the ignition system I thought of putting in a bushing, and putting some nails into it in a sort of V (the heads sticking out the back end of the bushing and the points coming close together on the inside to create a spark gap). Then I'd put a little hot glue at the top of the bushing to hold in the nails, and finally I'd fill the rest of the bushing up with epoxy and add a little bit around the heads (or just find something to hold the nails in and epoxy the whole thing). Then I could just use the heads and connect them to my stun gun. Would this work or would the plug of glue just be popped out?

Update: I could just clip the heads off of the nails, put them in parallel to one another, and glue the ends that the stun gun goes to so it won't arc. Sorry for the lack of pictures, I don't have a good drawing to put up.

[noname]

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 )
The picture up there is the inside view of the spark plug. I got a 1/8" NPT schrader valve, took the valve core out so it's just a hollow brass piece, screwed it into a steel bushing, poked a wire through, then filled the entire thing up with epoxy. What you're left with is a wire coming out of the schrader as one contact and the gun body itself being the other contact. Don't worry, it won't zap you. On the ignition end, you can bend/clip the wire to achieve whatever spark gap you want, then epoxy it permanently into that configuration.

[Juggernaut12121]

Thank you , I kinda figured my way was pretty bad xD

Alright, instead of a Schrader valve (can't find one) what about using a brass fitting like this

1/8'' barb by 1/4'' MPT

barb.jpg (20.43 KiB) Viewed 8723 times

I thought about using it in place of the Schrader valve, would this work? I also thought about using a spark plug but I heard a lot about them acting up so I wasn't sure

[noname]

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.

[Juggernaut12121]

Okay, once again thanks for all the help

[D_Hall]

Rather than a hose barb, I recommend moving to 1/4" air fittings for air compressors. Quick disconnects. Easier to work with. More robust. Readily available at any hardware store. Classy... But still affordable.

[Juggernaut12121]

Thanks! I'll probably go with that or a spark plug

[D_Hall]

Huh? Oh, crap. Somehow I got it in my head you were asking for advice on air/fuel lines and such. QDs are a bit more work but they make it easy to reconfigure/maintain the gun. As for ignition source, *definitely* go with a spark plug. It's what they were frikken designed for. Anybody who's having problems with them has *other* problems.

[Juggernaut12121]

Do you know where I can find any that have NPT threads? I've found a few online but they're all pretty expensive, that and should I insulate it with a pvc bushing or is that unsafe (I've saw some other people do it with success but I don't know what mixes they were going for)? And one lat question if you're willing, I thought using a tee in the middle of the chamber, then off of that tee I'd put another tee, one branch going off to a ball valve and fill port and the other to the spark plug. Would this actually be a viable ignition setup or would it create some sort of pocket creating trouble?

[noname]

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 insulating the spark plug from the rest of the gun.
Having your spark set back in a pocket isn't optimal. I've had ignition problems when I had a similar setup, but that shouldn't have happened so I'm still not sure what was going on. To be safe, I've stuck all my spark plugs directly into the main chamber with no turns or angles obstructing them. Seems to work.