I builded the fill tube folowing ideas of this UKHAS wiki page.
As I don’t have something to create a grove, I used a PVC waste water plug that already have some kind of grove by design.
- I strongly glued the flexible fill on it.
- To close the remaining space, I added some wet newspaper sheets to create a temporary “wall”.
- I used a hot glue gun, and let the hot glue fall all around the both sides of the newspaper.
- I drilled a small hole to attach a nylon cord to be used for weighting and to secure to the ground bebore launch.
I was very happy with it.
Looks strong and very easy to build.