i recently posted pics of my molds in another thread, 800mm long tapered tube with 2 part aluminum female mold. ill be trying a few different methods for consolidation. vacuum, which is pretty straight forward and i think i have a good understanding of, also will eventually try expanding silicone plug. Also would like to try an inflatable bladder. I understand there might be options for things that could possibly be used as is, like balloons, bike inner tubes, etc., but im also curious how to make my own custom bladder. I have a pretty good idea of some of the process, but missing some details. i will mill some concave end caps for the mold with an opening at larger end for inflating bladder. for making the bladder i will use 1.5 to 2mm wax sheets to build up mold wall so bladder is undersized. beyond that, im not really sure what to do. First of all, what should i use? latex? silicone? what kind specifically? can i just pour some into the closed mold, spin it around to coat the walls, pour out excess, then let dry? maybe multiple applications to build up a good thickness? Whats the best way do this and with what material?  this will be prepreg cured at 120c so the bladder needs to hold up to that

Excuse me, maybe a lot of time has passed ... but I am interested to know how you solved this matter, how did you make the bladder?