Peel Ply
Contents
General Description
A layer of 2.7 oz. Dacron fabric strips or tape laminated into a layup as if it were an extra ply of glass. The peel coat wets out with epoxy like glass cloth and cures along with the rest of the layup. However, the Dacron does not adhere structurally to the glass and when peeled away it leaves a surface ready for glass-to-glass bonding without sanding.
Velocity Use
Peel-ply is technically optional, but it is very advisable. First and foremost, it tends to pull excess epoxy resin out of a lay-up, making the final assembly lighter for the same strength. Secondarily, it makes the lay-up immediately ready for additional lay-ups without further preparation/sanding. Finally, it makes the lay-up much tidier and helps it lay down flat and orderly, avoiding the infamous "fishhook" or "meathook" phenomena. This is where the edges of a lay-up (typically BID) start to fray and curl as you lay them out, then during cure some of the them always curl up, ready to grab the first suspecting finger to come by to check on the lay-up.
Packaging Weights
Aircraft Spruce sells peel-ply in sheets and tapes of various widths.
Directions for Use
Once your lay-up is down, cover completely with peel-ply and wet the ply with epoxy, carefully working out any bubbles. It's best when your peel-ply extends a couple of inches past the edge of the lay-up, and it's most important to leave a piece (a bit past the end of your lay-up) that doesn't have any epoxy. Otherwise, it can be quite difficult to get a edge to pull the ply up later.
Safety and Handling
Make sure that you remove all of the peel-ply before adding any additional glass!!
