Over the last couple of years we’ve had a number of requests for a tutorial on splicing same sized bottles. We found that the technique we used to use ( http://www.aircommandrockets.com/construction_2.htm#SplicingBottles ) would work on 1.25L bottles but did not translate well to 2 Liter bottles. No matter how carefully we would do the symmetrical splices on the larger bottles we would often end up with a small leak and the whole splice had to be thrown away. Sleeves larger than 2L bottles which could be shrunk to size were also increasingly difficult to get.
So we developed a modified splicing technique, that we now use for 2L bottles. We posted the technique in outline form here http://ausrocketry.com/forum/viewtopic.php?p=26084#p26084 last year, but finally got around to actually finishing the tutorial this week. Talk about dragging our heels.
It’s by no means the only way to splice 2L bottles, but it’s a technique we’ve found reliable and haven’t had a single leak since we started using it. The splices hold up well to repeated launches and non-destructive pressure test cycles to 140psi. We are currently using it on our Acceleron V and Polaron VII rockets.
Here is the full tutorial that also includes a how-to video:
http://www.aircommandrockets.com/construction_6.htm
If people do end up using this technique, we would love to get feedback about what worked for you and what didn’t and perhaps ways to improve or even simplify it.