How much hairspray?

[Flying_Salt]

Hey I'm using my new combustion spud gun, but I put it away for a few days and now it seems to hate me. I'm using an average aresol hairspray, I want to know how much and how far away from my sparker I should spray it from. My sparker is a grill ignitor, and it's about 3'' from the end

[FreakyShotGlass]

Hairspray isn't very good for combustions, it leaves a sticky residue that insulates the electrodes. If you can try changing to a cleaner propellant, ideally propane or MAPP but even deoderant or butane will suffice. If you must use hairspray I suggest a very small amount and spray it as far away as possible.

[Extrusion]

It all depends on your chamber size but normally 2-4 seconds is good just exeperiment with the times.

Btw: after a few shots you chamber will have a thick layer of slimey hairspray in it.

Propane is a million times better and burns alot cleaner just letting you know, it is also very cheap.

EDIT: Shot glass beat me

[Flying_Salt]

Yes I have noticed the sticky residue. I'm not sure if I should use propane, because my PVC is only sch. 40

[FreakyShotGlass]

Sch 40 is fine for propane, I can't remember exactly the pressure created by the combustion but it is only around 50psi max. Sch40 pneumatics are safe to 100 psi and some have taken them to 120 and they haven't exploded.

[Flying_Salt]

If I were to use propane, how should I mix it?
I'm sorry, I'm really new to this.

[FreakyShotGlass]

You can start off by just using a propane torch head to insert the propane, you only need a little bit. But ultimately you need a regulator just search this site for Propane Regulator and you will find something, I'm pretty sure thaere is something in the how-to section.

[Extrusion]

just search for propane metering system there a bit costly i think (in my mind) but well worth it youll get the perfect mix everytime.

Just a thought but is propane heavier or lighter then air?

[Flying_Salt]

In a liquid form heavier, but in a gas form I think it's almost the same or lighter

[Extrusion]

I did some research on the density of gas propane and found out it is heavier im not sure bye how much but i got this quote "A bag filled with propane would drop like a baseball." so im thinking that means its heavier i havent got a metering systen so i inject propane manually and i normaly hold the propane tank under the chamber and fill it and i found out most of the propane sinks out when i do it this way (no wonder it takes me 100 tries to get it to fire.) i was still suspicious so i filled a bag with propane and tied it i let go and boom it hit the ground lol so its heavier no i will load my gun with the tank above the chamber form now on.

[Pete Zaria]

Just to clear a few things up (I hope):

I agree, PVC or ABS sch40 is safe for propane (as long as it's not cell core).

Theoretically, a stoichiometric (perfect fuel/air mix) propane combustion would generate 102psi. In practice, 85-90psi max.

A good propane meter system can be built for about $35. If you want to know how, search around this forum or ask me.

Yes, propane is significantly heavier than air.
Propane becomes liqiud above a certian pressure, I think it's around 110psi.

Peace,
Pete Zaria.

[Pyro Ninja]

would anyone have any ideas how to make some sort of nozzel for the end of a butane cans that they use for little portable stove things. so that its like an arasol can.

[FreakyShotGlass]

Get the lighter refill cans and then just pull one of the nozzles down by hand or with pliers and the butane will come out.

[Pyro Ninja]

thanks i didn't think of that

[Flying_Salt]

man I just scrubbed all that sticky junk out of my gun. Next time I see some propane I'll see if I can use it