drilling holes in pressurised chambers

[revans]

This is specifically applying to a bbmg, but it can be applied to anything that takes similar pressures so I put it here ...

Is it alright to drill holes in a chamber that will be pressurised to around 100 psi with a bike pump? I would like to mount something on the side of my bbmg, using a bracket with two 7mm screws that will be screwing into the chamber. Will this be pressure tight or will the screws alone not be good enough? I was thinking of sealing it up with jbweld and maybe i could use some telfon tape as well. thanks for any suggestions or comments, I'm being paranoid because I've never done anything with pressure before and I don't want any screws to fly out (see I am paranoid)

[ghostman01]

as long as you drill in the end caps or something that is thicker than the pipe it self i personally would mount something using brackets that mount to it using something that stays on the out side of the chamber

[XxtriviumxX]

What exactly would you be drilling in to? (different materials offer different options on how to do this, there for making it easier to give better suggestions )... And what are you intending to mount beside the chamber?... Personly i dont really like the sound of screws at 100 psi...

[psycix]

Drill in the part where the pvc is double as thick, like where a coupler, endcap or other fitting is glued on.

[JDP12]

yep, drill through an endcap or something, you should almost never drill through straight up PVC

[jrrdw]

Why not use screw clamps that rap around the outside? JBWeld should hold the pressure, but it seems to me once you develop a leak it's hard to stop.

[biggsauce]

Yeah I agree with jrrdw. Although JB Weld is one of the worlds great wonders and it has the potential to stop a leak, screw clamps are what I would suggest using first. Possibly use a chopped tee the size of your chamber if aesthetics is your main concern.

But, if you must, do as others have said before me and drill through a double layer of PVC. Spend time picking out the right diameter drill bit though. Obviously you want a hole large enough to tread a screw into, but it should be small enough that the threads have the most "bite" possible. The hole should be almost the diameter of the "main shaft" of the screw (main shat being the diameter if the threads were ground off)

You probably know this stuff, just trying to help. As long as you're smart about it, your BB<G shouldn't turn into a magic screw shooter

[revans]

Cheers guys, with a bit of design reworking I've got a non pressurised section to screw into, so as biggsauce said I wont have a magic screw shooter. Thanks for the suggestions though.

[DYI]

The title "drilling holes in pressurised chambers" made me fear for your life before I actually read the topic. Perhaps "drilling holes in pressure vessels" would be a bit more appropriate - your title implies drilling the holes while the chamber is already pressurised.

[Blitz]

Your title IS misleading... I seriously felt the need to create this: