Plugs and molds
When I started making my wheel pants, I experimented with a few different adhesives to use on the joining tape. I tried 5 min, 30 min epoxy, thin CA glue, Zpoxy finishing resin and then what i use for making the parts, Fiber Craft Aqua-set epoxy resin.
The 5 and 30 min are to thick and CA simply doesn't work well. Zpoxy finishing resin works well. What you need is a epoxy resin.
Now when you made the tube, did you put on 1 layer or multiple? Multiple is better. I think I seen the glass you have and it's probably a 6oz or higher thickness. That should work.
I also am very new to glassing and there is lots to learn, but this is what I have learned by trial and error so far. I hope others can reply with their experiances so we both can lean.