ORIGINAL: davidfee The epoxy makes effectively thousands of little rivets through the hinge material. I'd love to see you pull one apart without destroying the rest of the structure first.
David's right. I used to worry about this because the tape material I was sold as 'peel ply' was in fact was re-packaged 'something else'. It had a greasy feel to me almost like teflon coating, epoxy seemed to come off easy so I chickened out. I never did find out what it was. I have since pulled enough legitimate treated peel ply off of bagged sections & takes some effort. Sometime I worry about pulling the layup off a well released mold. So I dont worry about this anymore, peel ply is probably fine, I just prefer the toughness of kevlar. I think any problems are more related to insufficient epoxy application, or epoxy which has wicked into the balsa skin & starved the 'riveting' process or meat hands have delaminated the joint during the flexing step.