Threaded PVC end caps- waterproof?

[m_g]

Hi all,
I am thinking of building a waterproof housing out of 6 inch PVC pipe (3mm thickness) reinforced inside to prevent flex, with a glued on, push on end cap on one end, and a threaded end cap (with o ring) on the other. All are just standard plumbing parts.

Has anyone tried this, or know whether the threaded end caps could be waterproof to 20 or so metres?

[bikerbones1968]

Hi m_g. I think 3mm is pretty small even at the depth you mentioned. Can you get your hands on any Schedule 80 PVC well pipe? Its at least 11.5 mm thick and is good for 60 meters without reinforcing. The other advantage with the thicker pipe is you can do what I am doing for a far better proven seal. Using a router or a lathe if you have access to one machine an oring groove in the face of the end of your pipe. Place your dome or your flat lens (depending on your design) against the oring, place your lens cradle to fit over the 6" PVC on and tighten the lathes down to hold everything in place. You don’t need much pressure to keep the water out at this point and the bonus is the deeper you go, the more pressure is placed on the seal and the better your seal will become.

1st Image: Toggle latch affixed to the hull, latch keeper affixed to the lens cradle.

2nd Image: Where to cut your oring groove.

3rd Image: Oring installed lens dropped in the lens cradle and ready to be secured. (sorry the protective paper is still on the acylic lens)

[james sowell]

ok o-ring so its pipe end with grove o-ring lens o-ring cap ? now is that just a end cap with the center cut out? thanks

[bikerbones1968]

It’s actually a handmade reinforced fiberglass lens cradle slightly larger in diameter than the PVC pipe. It was made first by turning out the basic shape on a wood lathe made from pine. Then ballistic gel was poured over the wooden "plug" while sitting in a larger diameter plastic pail bottom. The gel when cures makes the reusable "cradle mould".

Next, many small 1/2" x 2" pieces of fiberglass mat are cut and soaked in 2 part fiberglass resin. Using the gel mould all the pieces are crammed into the gel mould until stuffed full and left to cure overnight. When done pop it out of the mould and you have one very very strong reinforced part.

[james sowell]

ok thanks

[bikerbones1968]

James, I am sure a pipe cap with the center cut out for the lens and a little sanding to make it a loose fit it would work just fine.

[james sowell]

yea im thinking how to get the grove in it on the next 1, geting ready to do a leak test on my first 1 ,it helps looking at outher ways of doing it, all power wires in back pain to get batt. and camera in

[bikerbones1968]

Cutting the oring groove is easy to do using a router table and the appropriate size bit. First glue at least four wooden spacers to a piece of Masonite that tightly fit the inside diameter of your pipe. With the pipe in place glue several more small pieces of wood around the outside diameter. This will firmly hold your pipe in place when you cut the groove.
Use a pencil to trace the inner and outer diameter on the Masonite. Next drill a small hole through the Masonite in the center of the traced outline of the pipe. This will be for your router bit to cut the oring groove. The pipe has to be 100% flat and square before you begin to cut the groove. Measuring the diameter of the oring, divide the diameter in half. This will be the appropriate oring groove depth. Now with your router running, and the depth of the bit set, place your pipe on the jig and by hand, slowly turn the pipe a few complete revolutions and you’re done. Any slight imperfections can be smoothed perfect with very fine wet/dry sandpaper.

The image only shows a few guides blocks glued in place on the outside diameter but you can see the glue residue where they should be.

[james sowell]

very nice

[bikerbones1968]

Thought you might want a tip on how to get a perfectly flat, square and true surface before you machine your oring groove. First you must construct a jig box to hold the pipe. Using just a square and some scraps wood and woods screws build a simple box that tightly fits the diameter of your PVC pipe. Like this below.