SpudFiles

I'm guessing it didn't work out to well since your trying to use a spark plug, but the more I think about it, the more I say try the spark plug idea, its something different and would be cool if it worked out.

Looks like it can handle some pressure.

A few things, though. First, I would hydrotest it. You may say "What!? Nobody hydrotests their hybrids!", but since this is a homemade vessel, it'd just provide you with that extra piece of mind. It's a fairly simple process. Since you've gotta mount a gauge anyway to monitor mixture pressure, tap some 1/4" or 1/8" threads into the pipe and install a small 0-3000 PSIG gauge. Install the bushings to reduce the 1" FNPT end of the union to 1/8" FNPT, and install a grease fitting, (with check). Open the union and dunk underwater to completely fill with H₂0. Close the union, (underwater), and bring back out. Now, hook up a filled grease gun to the nipple and pump away. Test it to 3x you theoretical working pressure. If that's too high, then maybe just 2x.

Second, the union doesn't really have a "preferred" direction, but you most probably will have to install some sort of rubber gasket inside of it to seal completely with a burst disk in it. They seal great when there's nothing in them, but when you start sticking aluminum sheets into there, they start to leak. I've got simply a bored-out garden hose washer on my hybrid. Works great.

All in all great. Hope to see some progress fairly soon.

great job cant wait to see it in action. havent seen to many hybrids lately glad some one is making one

markfh11q wrote:Looks like it can handle some pressure.

A few things, though. First, I would hydrotest it. You may say "What!? Nobody hydrotests their hybrids!", but since this is a homemade vessel, it'd just provide you with that extra piece of mind. It's a fairly simple process. Since you've gotta mount a gauge anyway to monitor mixture pressure, tap some 1/4" or 1/8" threads into the pipe and install a small 0-3000 PSIG gauge. Install the bushings to reduce the 1" FNPT end of the union to 1/8" FNPT, and install a grease fitting, (with check). Open the union and dunk underwater to completely fill with H₂0. Close the union, (underwater), and bring back out. Now, hook up a filled grease gun to the nipple and pump away. Test it to 3x you theoretical working pressure. If that's too high, then maybe just 2x.

Second, the union doesn't really have a "preferred" direction, but you most probably will have to install some sort of rubber gasket inside of it to seal completely with a burst disk in it. They seal great when there's nothing in them, but when you start sticking aluminum sheets into there, they start to leak. I've got simply a bored-out garden hose washer on my hybrid. Works great.

All in all great. Hope to see some progress fairly soon.

Holy shit
Thats a great idea man!
Have you used this method before for hydro testing?
What threads do grease guns have?

The thread off the gun is 1/8 NPT I think. I could be wrong but the 1/8 brass fittings fit great.

I haven't tried it, but I believe it was plasticex009 on the Spudtech forums who did things like test a sprinkler valve and other things.

I think it's a good idea because I've destroyed by accident with a grease gun before.

frank, if you don't mind me asking, why did you choose to weld a piece of rectangular shaped plate on the arse end of the gun instead of a traditional cap?

looks like you will have one hell of a creation when you are finished with it.

good luck with it.

You could almost get away with acetylene!

chaos wrote:frank, if you don't mind me asking, why did you choose to weld a piece of rectangular shaped plate on the arse end of the gun instead of a traditional cap?

looks like you will have one hell of a creation when you are finished with it.

good luck with it.

I think he was too lazy to get a cap or too lazy to cut it round.
Or the cap didnt fit.

psycix wrote:

chaos wrote:frank, if you don't mind me asking, why did you choose to weld a piece of rectangular shaped plate on the arse end of the gun instead of a traditional cap?

looks like you will have one hell of a creation when you are finished with it.

good luck with it.

I think he was too lazy to get a cap or too lazy to cut it round.
Or the cap didnt fit.

Bingo!
And a cap would have cost me some more $
I could round it off but it helps work as a stand.

mopherman wrote:

Novacastrian wrote:Very solid looking set-up, gook luck with the piercing.

how did your peircing go? I remember you said you wanted to try it with your hybrid

I have not tried to pierce the steel plate yet. I was planning on making a discarding sabot designed like an anti-tank round.
My Hybrid has a barrel id of 23mm and the dart i made (now gone) was 6mm with a 4.5mm Penetrator (sharpened allen key), however to make a sabot that small was going to be a pain in my big lathe, i really need a smaller chuck because the smallest i can hold is 8mm dia.
Hence i scraped the idea of the anti-tank sabot for my Hybrid, i will however be making one for my 33.7mm Combustion.
I will be making a dart to be fired with a sabot from my Hybrid nontheless, then i can see if i can penetrate the plate steel.

My only advice would be to keep the penetrator dia small, like 4-5mm and use a super tough material like 4140 or some such, or an old allen key.

cant you also drill a hole and then weld a nut over it? then screw the spark plug into the nut. thats what id do anyway........

you can do, but the nuts for sprak plugs(in the uk anywhay) are bitches to find..

They make nuts for spark plugs?
Never seen them, not even in my automotive classes.
hmm.
but I think that maybe I might TIG the plugs to keep the heat down and help prevent the sparkplug from getting too hot.

Very nice creation! It looks great! Where did you learn to weld? I have wanted to learn, but just don't know where to start (though, considering I am the WORLD'S WORST SOLDERER, I don't know how welding would work out ).

I have that same union, but in 2" for my hybrid (which I have been working on for so many months; its all done, but I need to build the Generation II fueling chamber).

Can't wait to see this beast in action!