Peel-Ply Removal

[bluwtrlynn]

I am getting ready to lay-up some superstructure panels from foam-epoxy-glass for a fishing boat to trawler project. I will lay the glass up then vacuum bag to, hopefully, save sanding. I will use peel ply on the outboard surface which will eventually be painted. My question is how long I can leave the peel ply on? Does it have to be removed when the glass is still green? Can I leave it in place until I am ready to paint, possibly several months, to protect the surface from collecting?

[Ssor]

I always leave it on until the resin is cured but never had occasion to leave it on long term. If it is shielded from UV degredation I suppose you would be alright but nylon doesn't have much long term resistance to UV. If it broke down you might find that it would not be storng enough to pull without tearing. It does give a nice smooth finish.

[AVMan]

Some composite sandwich panel manufacturers purposely leave peel ply on after manufacture so that the builders will have a clean bonding area when they need it, no "shelf life" is ever given (at least to my knowledge), but as bluwtrlynn says, if its been exposed to intense UV for extended periods of time you might have trouble removing it.

[bluwtrlynn]

We don't get too much intense UV here in Seattle. Just kidding. Actually the boat is tented so I probably don't have anything to worry about. I'll just check periodically and strip the peel-ply off if it seems to be falling apart. Thanks for the input. Lynn

[Ssor]

Lynn, you really need to pull it off about a week before it starts to fall apart. What you need to find is a "failure anticipator".

[fhrussell]

also, take into account the quality of the peel-ply. i purchased some awhile back that was at a much lower price than i was used to paying and it only comes off with quite a bit of muscle. if this stuff were left on for very long, it would be a real challenge to remove if it deteriorated. i like to leave it on until i'm ready to prime and paint, leaving an uncontaminated surface when it's removed. with the less expensive peel-ply, i've been removing it within 48 hours of application.