Clive,
I have always struggled to get consistent tension when winding peelply, so the tube ends up a bit bumpy. How do you recommend winding to keep everything neat?
Hi Phil,
It is certainly an issue.
To state the obvious for things that help:
We try to accurately double wrap.
We limit the max laminate thickness by doing multiple hits.
I am a great fan of getting it all really warm so that the resin viscosity is low and the peel ply can really pull down.
For mast manufacture we pre heat the resin and mandrel to 80C.
For repairs I use the heat gun and back off if the resin starts to boil or when I see smoke.
I always feel that even in the bumps there is significant pressure and consequent consolidation.
The dips show how much more it could be pulled down.
When Roger is making tubes he has a wall mounted high torque motor drive that makes it much easier to wind accurately with really high tension.
It is not unrealistic to get 50 ponds of tension in the peel ply doing it this way. On a 2" tube with a double overlap of 50mm peel ply that gives a consolidation pressure of 25PSI.
Heat shrink may give a pretty finish easily but I don't think that it really consolidates.
We broke the top mast on Subtle's Ctech just before Pwllheli and looking at the fracture it was clear that they had used prepreg with heatshrink. The fibres were not well bonded and this resulted in the compression failure when they buckled during a gybe.
Clive