WHO HAS BEEN SUCCESSFUL WITH 2 PART BLADDER MOLDS?

I made a 2 part bladder mold/tool to make sq carbon tubes. inch 1/2 X inch 1/2. Have made a sample 14" long, fg twill and some old epoxy. Turned out great but my tool is 5 and 1/2 feet long. Its a easy cf layup but l need to perfect my bladder/I used a bicycle inner tube & it did not stick but this was short piece.

Yea, saw that and like this too: Been hunting stuff!

Yes I use bladders quite often and use a range of materials but mainly bespoke Latex bladders which we make in house, unfortunately its not a process that I can cover in a few paragraphs .However just a few observations regarding your current method , as your mould is open ended your are going to be limited to the pressure you can apply.  It also helps if you have small  channels in the flanges for the excess resin to escape if you make a sealed mould. To make a suitable bladder for you current project you could use plastic tubing from a DIY store as a mandrel and build up your layers of latex on the outside.

Making own latex lil' later, now l like that idea if my nerves hold out.