many thanks for the tips
I'd been considering kevlar inside ( bummed some off one of the pipe repair contractors ) but the wood inserts would make it easier to get some higher density foam under control.
Should I try and get rid of the existing foam , it doesn't seem to have any strength & is friable ?
nearly have the plan now <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />