4" Burst Discs

[MaxuS the 2nd]

What on Earth would I use?

[frankrede]

Paint can lids.
Sheet metal

[SpudUke5]

Aluminum (from a pop can), plastic (from something like a gatorade bottle), aluminum foil.

cant think of anymore atm.

Go with what frank said, i think that will be better.

[MaxuS the 2nd]

Ahh yes of course, very thin sheet metal..Why thank you.

[psycix]

Whole rolls of alluminium foil
Indeed, sheet metal would be better.
Though on a larger scale and pressure, burst disks become really expensive.
You may not need any projectile anymore because the BD shrapnel already rips stuff apart. (Larda's 200X hybrid)

What pressure are you using?
The thickness of your burst disk matters not only by diameter, but mostly by pressure!

You could also try other sheets:
Sheet pvc or other plastic, maybe wood if you can get it to seal.
Circles of sheet metal out of the doors and hood of your dads or neighbours car...

[MaxuS the 2nd]

It's only in 10bar rated PVC, but has a setup similar to that of sgort's burst disc pneumatic. With a pneumatic actuator. I'd be using it at around 100psi.

[VH_man]

where the hell did you get a 4 inch union?

[Hotwired]

Amazing the kind of things you can get in the UK

[MaxuS the 2nd]

I'm not using a 4" PVC Union. I'm using Camlocks.

[D_Hall]

God forbid that you actually use burst disks?

[JDP12]

4 inch cam locks wtf! Them things are expensive!

and i think burst disks at that size, could become pretty dangerous with the shrapnel and all...

[SpudFarm]

and i think burst disks at that size, could become pretty dangerous with the shrapnel and all...

lol! x)
you dont HAVE to be infront of the cannon and if you are i think the 2kg lead slug will get you first xD

[MaxuS the 2nd]

4 inch cam locks wtf! Them things are expensive!

Not really, it was the cheapest option.

£30 ($60) for both the male and female parts. Aluminium ones that is.

@D_Hall: Indeed. Although if I do eventually use Aluminium Foil, I will need like 200 hundred layers to take up to 100psi and not burst.

[Hotwired]

A 4" diameter port could be called a good time to transfer from foil to sheet metal.

[starman]

You could try those thick cardboard beer coasters from bars and restaurants. Probably won't make it up to 100 psi though at the 4" size.