Nozzle Issues

[DogLover]

Here is the design I have for my nozzle:

Nozzle Assembly.png

I am having a problem with it leaking between the bottle and the nozzle.

Leaking Problem.jpg

What is the best material to seal against water leakage? I know I sound like a simpleton, but I have tried all sorts of material (rubber, foam, hose gasket, etc.) and I still have the leakage. One thing to note is that it leaks only above 40 psi.

Thanks!
-DogLover

[U.S. Water Rockets]

Here is the design I have for my nozzle:

Nozzle Assembly.png

I am having a problem with it leaking between the bottle and the nozzle.

Leaking Problem.jpg

What is the best material to seal against water leakage? I know I sound like a simpleton, but I have tried all sorts of material (rubber, foam, hose gasket, etc.) and I still have the leakage. One thing to note is that it leaks only above 40 psi.

Thanks!
-DogLover

Have you tried taking the plastic seal out of a bottle cap and cuttin a hole in the middle? Those make very good seals.

Your problem might be the newfangled bottles they came out with recently which try and save plastic by making the threads shorter. Pepsi started them first and coke followed suit. Now nealry all bottles have 2 threads on the top instead of 3.

We have a video explaining the differences:


If you stick a gardena in a cap with only 2 threads then it takes up the space of one whole thread and you get hardly any grip on the bottle and the cap will leak no matter what gasket you use.

If you can find an old-style bottle cap with the 3-thread (look at beverages which come in odd shaped bottles in the store because they are less likely to change their custom molds until the molds are worn out). If you use a 3-thread cap with the gardena inside it should still leave the 2 remaining threads for your new style bottle to grab.

[Azriel]

Here is the design I have for my nozzle:

Nozzle Assembly.png

I am having a problem with it leaking between the bottle and the nozzle.

Leaking Problem.jpg

What is the best material to seal against water leakage? I know I sound like a simpleton, but I have tried all sorts of material (rubber, foam, hose gasket, etc.) and I still have the leakage. One thing to note is that it leaks only above 40 psi.

Thanks!
-DogLover

Have you tried taking the plastic seal out of a bottle cap and cuttin a hole in the middle? Those make very good seals.

Your problem might be the newfangled bottles they came out with recently which try and save plastic by making the threads shorter. Pepsi started them first and coke followed suit. Now nealry all bottles have 2 threads on the top instead of 3.

We have a video explaining the differences:


If you stick a gardena in a cap with only 2 threads then it takes up the space of one whole thread and you get hardly any grip on the bottle and the cap will leak no matter what gasket you use.

If you can find an old-style bottle cap with the 3-thread (look at beverages which come in odd shaped bottles in the store because they are less likely to change their custom molds until the molds are worn out). If you use a 3-thread cap with the gardena inside it should still leave the 2 remaining threads for your new style bottle to grab.

Likewise generic soda bottles seem to be keeping suit with the 3 thread "old caps" rather than diving into the 2 thread "new caps". I am a huge fan of the old style. Better for water rockets and a lot of other uses for the bottles than the new caps are.

[Nick B]

Are you using a brass coupler?


I have plastic couplers, that I use, they do not match the bottle threads, but they engage enough for me to use them with just an added garden washer or two.
I'm good to 120 psi.

Your pressure leak is probably air going around your washer and leaking past the mangled bottle top OEM seal.

Unless you need high pressure and brass or some specific coupler that can be drilled out, IMHO, drilling a thru hole and grinding down a coupler and mating the two, is an often unnecessary application.

[Nick B]

If the thread height is too short, just grind down the cap or coupler entry side. It will alter the depth setup, to a more shallow seat.

[DogLover]

Thanks for all the ideas!!! One thing I forgot to mention is that I am not using a bottle cap, but a cap like item from a lotion bottle. I found one where the threads match very well. I will try a seal from a bottle cap. I have tried using a bottle cap before but once I drill a hole large enough for the nozzle to stick through, there is not enough area on the cap to hold the nozzle in. I will keep experimenting!!!

-DogLover

[Nick B]

You guys may be over evaluating the need for complete use of the threads.

Consider that tooling like pressure washers that use 1/8 turn slots and pins, and similar, do the job of retaining and holding pressure.


just sayin.

[DogLover]

Ok, I figured out my problem. When I cut the nozzle the cut end wasn't perfectly even. So after I sanded it down to a ultra smooth surface, and polished it, which might have been over kill, it doesn't leak near as bad. If I put thread tape on the threads, it doesn't leak at all.

-DogLover