Water Rocket Forum

Looking to pick some of the great rocket minds out there, I'm just getting started and I have my first launcher assembled. My problem is in the quick connect (garden hose) My first rocket I used the male connect right onto a 7-up bottle. the fit wasn't air tight, so I used a little jb weld. The seal was good but upon lift off, It took a very hard arc, indicating what I think was maybe too much weight on one side of cap. My second try was to cut the male adapter, and put it inside the cap. This time I didn't have a good seal. I had to cut the adapters threads away with a dremal to fit inside the cap.
ANY THOUGHTS ON SUBJECT? of using quick connect and how to use bottle cap? I like the brass connects, but can't find a plastic male to fit into brass female connect. thinks for the time.

Hey there,

I use the Gardena method as well and I sure had some problems too...
That's one of my early nozzle designs, as yours it leaked. Now I make them like that: I use the male gardena as it comes and cut a new thread (3/4") in the bottle neck.
Here's how: With a hot knife I "melt" the existing PET-thread and make it even. then I cut the new thread. Very simple actually. Then I wrap some tape to make it tight around it and simply screw the the male gardena on. Here's a close up: As you I use a female brass connect. I never a the problem that the male didn't fit though. Here is also a video about my launcher. Maybe this helps too:
[youtube][/youtube]
About the stability: Try glueing some weight to the nose and/or add fins.

Hope this helps

Christian

This is my metod with 9 mm male gardena:


1 - With a hot knife melt the existing PET-thread
2 - Sand the area until it becomes even.
3 - Screw the male part and see if it fits correctly
4 - Remove the gardena.
5 - Put any super-glue on the melted area of the PET (doesn´t need to be poliuterane)
6 - Insert the the gardena.
7 - Wait 1h and then test it. That´s it !

RaZias wrote:This is my metod with 9 mm male gardena:


1 - With a hot knife melt the existing PET-thread
2 - Sand the area until it becomes even.
3 - Screw the male part and see if it fits correctly
4 - Remove the gardena.
5 - Put any super-glue on the melted area of the PET (doesn´t need to be poliuterane)
6 - Insert the the gardena.
7 - Wait 1h and then test it. That´s it !

You can take the threads off a bottle really quickly with a grinding wheel. You can even get one that mounts in a regular hand drill. It would be faster than melting and sanding the threads off.

U.S. Water Rockets1 wrote:

RaZias wrote:This is my metod with 9 mm male gardena:


1 - With a hot knife melt the existing PET-thread
2 - Sand the area until it becomes even.
3 - Screw the male part and see if it fits correctly
4 - Remove the gardena.
5 - Put any super-glue on the melted area of the PET (doesn´t need to be poliuterane)
6 - Insert the the gardena.
7 - Wait 1h and then test it. That´s it !

You can take the threads off a bottle really quickly with a grinding wheel. You can even get one that mounts in a regular hand drill. It would be faster than melting and sanding the threads off.

That's right. I did that too but then it was just a tiny bit too small. That's why I melt it now. It fits perfectly!

ah the nozzle, the main Obstacle for me....sigh.....oh well, Maybe i'll shove a piece of Card board in a cone shape up the neck and see if that works

Hi,

I can second on Chris´ method: Cement the male coupler over the throat of the bottle. Don´t use a cap.

I see that you have both a Dremel and JB Weld, so you are set to go!

Regards
Soren

chriswaterrockets wrote:

U.S. Water Rockets1 wrote:

RaZias wrote:This is my metod with 9 mm male gardena:


1 - With a hot knife melt the existing PET-thread
2 - Sand the area until it becomes even.
3 - Screw the male part and see if it fits correctly
4 - Remove the gardena.
5 - Put any super-glue on the melted area of the PET (doesn´t need to be poliuterane)
6 - Insert the the gardena.
7 - Wait 1h and then test it. That´s it !

You can take the threads off a bottle really quickly with a grinding wheel. You can even get one that mounts in a regular hand drill. It would be faster than melting and sanding the threads off.

That's right. I did that too but then it was just a tiny bit too small. That's why I melt it now. It fits perfectly!

Your message reminded me of an idea I used years ago to put threads on a PVC pipe when the threads were stripped. That time it worked very well and I thought it might work on a bottle.

I took an old hose nozzle that is made out of brass. I removed the rubber gaskets and then heated it up with a propane torch. Once it was very hot I screwed it onto the top of a bottle and it melted the existing threads into the shape of the brass nozzle threads. After it cooled off, I unscrewed the brass nozzle and screwed on a gardena connector and it went on perfectly. If glue were to be applied to the threads I think it would be perfect.