This blog covers the day to day progress of water rocket development by the Air Command Water Rockets team. It is also a facility for people to provide feedback and ask questions.

Sunday, October 25, 2009

Splice test #2 - Epoxy

After letting the epoxy splice sit for a week we pressure tested the spliced-pair to destruction today. At around 120 psi a small leak developed. We kept increasing the pressure until the splice failed at ~150psi.

This time it was the PET bottle that failed rather than the splice. It fairly cleanly tore itself off from around the edge of the sleeve. The epoxy glue though separated cleanly from the bottle that flew off. This means that the epoxy did not do as good a job of holding onto the PET, even though the 1cm x 1cm tests showed promising results.

The sleeve was glued on with PL premium.

We are now waiting for the sikaflex and PL to cure on the next splice test.

The reinforcing shells worked well and the bottles did not show any signs of stress in the neck area. We have taken them off again, and will use them on the next splice test.



Anonymous said...

Hi there,
I know a glue called ACRIFIX, that is made for Plexiglas, but it seems very good on PET bottles, as it appear to penetrate and diffuse through the plastic and you can't tell where the glue ends and the plastic starts.
I didn't use it for water rockets, though, so no idea how it will fares under extreme pressure, but I'm sure is worth a try.

...and keep going!

Andy Mc said...

Gday Geogre
I am trying this splice as well geogre, but i dont have PL glue. I only have sikaflex and i glue the two bottles together but i havent glue the sleeve on. I am going to try sikaflex and a sleeve with sikaflex and vice glue together. I am only using the 1.25L bottles at the moment.
Do you think this could work. What are you thoughs on vice glue and Sikaflex together.

George Katz said...

Hi Andy,

It will be interesting to see how you go with the VISE. The combination of VISE and sikaflex should work okay I think. VISE holds pretty well to PET so it should be good for the sleeve.

The 1.25L bottles haven't been too much of an issue for us, it's the 2L ones that have always given us trouble.

Please let us know how you go with your tests.


- George