Question on the use of peel-ply

When using peel ply over fiberglass with G-flex epoxy, do you wait until the epoxy has completed hardened before removing the peel-ply ?
Or do you remove it while the patch is still tacky?

In my limited experience the peel ply is left on for at least a couple of hours
To me this is is kind of clear as mud but it seem you can wait till cured
http://www.cstsales.com/peel-plies.html

Good heavens ! My little brain couldn’t keep up with all that info, so I gave up half way through.
I have always used a clear stiff plastic with good results except for the sharp bends on the bow and stern and was thinking of trying peel ply on a long inside curve that I am getting ready to do.

I had dinged up my RapidFire and was in the Adirondacks and made an appointment with Joe Moore at Placid Boatworks for repairs. There were a couple of soft areas that required reinforcement. He used Kevlar and Peel Ply with a vinylester resin. As I wanted to grab the last ferry to Burlington I was the little kid…when can I go when will it be ready… Two hours was what we settled on though longer would have been fine

I always wait over night before pulling it off - 8-12 hours. Leave enough material hanging of the end the get a good grip, and peel it away from the epoxy. Never had a problem with this timing.

Treated mold release fabrics can theoretically be left in place until the epoxy has cured. I usually remove it when the epoxy is still in a green state, however.

Some will use a tight weave nylon cloth as peelply. This is untreated and should be removed when the epoxy is still green, or it can be pretty tough to get off.

Thanks to all of you.
I’m still not sure if I’ll use it. The cost is more than the fiberglass, and the unknown make me want to do it as I always have, (with out it)

Unless you are really averse to sanding fiberglass, and some are, I don’t find peelply of great benefit for fiberglass cloth repairs. It is very useful for laminating aramid cloth because that is much harder to feather at the edge of patches. Fiberglass sands very easily. If you want a smooth fiberglass patch, just fill the weave of the cloth fully with epoxy, and feather the edges by sanding. A very smooth surface on the body of the patch can be achieved by wet sanding with fine grit paper.

Peelply also leaves a matte textured surface, so if you are going for a smooth surface you will need to apply another thin layer of epoxy anyway.

@pblanc said:
Unless you are really averse to sanding fiberglass, and some are, I don’t find peelply of great benefit for fiberglass cloth repairs. It is very useful for laminating aramid cloth because that is much harder to feather at the edge of patches. Fiberglass sands very easily. If you want a smooth fiberglass patch, just fill the weave of the cloth fully with epoxy, and feather the edges by sanding. A very smooth surface on the body of the patch can be achieved by wet sanding with fine grit paper.

Peelply also leaves a matte textured surface, so if you are going for a smooth surface you will need to apply another thin layer of epoxy anyway.

I always get a glass like finish when I tape a stiff sheet(s) of plastic film over the patch, but that is always difficult on a inside curve