# PVC/plexiglass pressure cap

1. Nov 6, 2005

### elixirnova

Yes, I'm new here so forgive me if im in the wrong forums. I am currently assembling a submergable underwater camcorder housing of 6" diameter pvc pipe. I was wondering what is the diference between plexiglass and double strength plexiglass concerning the pressure it can withstand.

I am going to need to be able to submerge it at most around 2-3ft. I'm sure I can find information on what kind of pressure the water will exhert at 2-3ft below surface, but i don't have a clue what kind of pressure plexiglass itself can withstand. Also if anyone could inform me about double strength plexiglass, would it be any better, or is single strength plexiglass enough to withstand the pressure it will encounter?

2. Nov 6, 2005

### Q_Goest

Only 2 or 3 feet? Don't worry about it, you could make it out of your mom's best china and it would survive! lol If you take it down below about 100 feet, then you might want to do some calculations.

3. Nov 6, 2005

### Danger

Unless there's some other reason that you need that kind of housing, you might as well just tuck the camera into a Zip Lock bag. It might not be optically clear enough for you, but it would certainly handle more pressure than you'll be dealing with. (Plus you can work the controls right through it without any mechanical connections.)

4. Nov 6, 2005

### elixirnova

Well next time I'll remember to go grab a $.99 big bottle of Vess Cream Soda. And use it :rofl: . But till then i guess ill sell a few of these to make back the$30 I paid for PVC pipe :grumpy: .

Another odd question but ever use pvc threaded caps? can they withstand pressure or are they vaunerable to leakage?

5. Nov 6, 2005

### Q_Goest

Threaded caps are fine, the vast majority are pipe thread. Just put a sealant on the thread and tighten down. There are all sorts of pipe thread sealant. One of the most common is Teflon tape, you just wrap the tape (not sticky) around the male threaded half like a condom and screw them together. I haven't had a complaint yet....

6. Nov 6, 2005

### FredGarvin

Make sure you wrap the teflon tape in the right direction!

7. Oct 3, 2007

### mashsoccer

Plexi Glass

I have a similar question as did the man with the plexiglass pressure camcorder. I am wondering how much pressure plexiglass can withstand because I'm doing a submersible project and I need to know if I could use plexi glass for any part of the outer hull of my submersible going down 1000 feet!!!Please help anyone

8. Oct 3, 2007

### mashsoccer

I dont know anything abot plexi glass

9. Oct 3, 2007

### mashsoccer

Anyone know anything:rofl:

10. Oct 3, 2007

### mashsoccer

:rofl::yuck::zzz:

11. Oct 3, 2007

### FredGarvin

The depth allowable is going to be a function of the hull thickness (among other things). How thick is your hull?

Just as a measure, at 1000 ft, the hydrostatic pressure is going to be about 430 psi.

12. Oct 3, 2007

### brewnog

Is Plexiglass another trade name for Perspex? I.E. acrylic?

13. Oct 3, 2007

### FredGarvin

Pretty much. Yes.

14. Oct 4, 2007

### Danger

While regular acrylic is very strong, it's prone to scratching and thus becomeing cloudy. If the environment in which you're going to be using it is in any way abrasive, I'd consider bonding it to the back side of a thin pane of glass.