Water Rocket Forum

My widemouth launch tube is now happily curing. It is composite tube made 1/2" PVC, 2 female slip to female threaded couplers, and 1 male threaded to female threaded connector, and a thin wall aluminum tube sheath.

The widemouth tube will screw directly on to my existing 1/2" launcher.

Still need to come up with a release mechanism.

So the part that is curing is the metal tube to the pvc?

Water Rocket Expert wrote:So the part that is curing is the metal tube to the pvc?

Right, I used cement on the internal pvc connections and then sanded everything and coated the pvc couplers in PLP.

The slot where the O-ring will go is threaded so it can come apart there. Haven't decided on a o-ring yet.

How deep is that o-ring groove? You may have problems if the thickness of the o-ring is too small.

I could be wrong but I would imagine standard garden o-rings would work. I have used them with PVC and they fit.

Water Rocket Expert wrote:I could be wrong but I would imagine standard garden o-rings would work. I have used them with PVC and they fit.

Yep need a larger one.

U.S. Water Rockets1 wrote:How deep is that o-ring groove? You may have problems if the thickness of the o-ring is too small.

Right. Likely I will fill that in with something. Going to decide after I visit Grainger.

Looking good! I got a small collection of 3L bottles too that have been eagerly awaiting a launch tube. I was planning on using 1" PVC and getting it turned down a millimeter or two, since it such a close fit. I may try using your method.

Your lucky that you live near a Grainger :/

DogLover wrote:Looking good! I got a small collection of 3L bottles too that have been eagerly awaiting a launch tube. I was planning on using 1" PVC and getting it turned down a millimeter or two, since it such a close fit. I may try using your method.

Your lucky that you live near a Grainger :/

Very lucky. There are many things I would have purchased from Grainger if I could. Maybe online but not as good.

Tested up to 50psi tonight. Looks like it is going to work.

O-ring actually came from a hose variety pack at Stuffmart. The outside diameter is too small until you dial it in by screwing down the top lauch tube. Variable o-ring!

No milling, just shaved off the gripper ribs on the 1/2" pvc couplers.

Next I need to add a release and hope to test launch this weekend.

WRE looks like you nailed it on the o-ring comment.

I know what you mean by the variety pack of O-rings. Isn't that the pack of brown flat ones and black round shaped ones. The problems is when you remove the piece to take on off it breaks to easily.

Water Rocket Expert wrote:I know what you mean by the variety pack of O-rings. Isn't that the pack of brown flat ones and black round shaped ones. The problems is when you remove the piece to take on off it breaks to easily.

Not too concerned. My derby launcher has a male threaded coupling on tube 1 with over 200 launches on it. Regardless, at some point here I'll be switching my lowers over to steel.

I mean the slip that you store them with. It goes through them all. Well for me, that part keeps breaking and they get lost.

Water Rocket Expert wrote:I mean the slip that you store them with. It goes through them all. Well for me, that part keeps breaking and they get lost.

Oh ok you meant what the washers came in/on. Sorry misunderstood what you meant. These came loose in a bag. I have small parts drawers and trays for that sort of thing so I just toss em in there.

Oh I see for me they come on a rod with caps and I always end up breaking the caps.