Fiberglass wrinkles

I have some 2.5 oz glass cloth that is wrinkled. The wrinkles don’t want to come out when I lay up the cloth. Is there a way to get rid of the wrinkles before layup? Ironing perhaps?

spray a light mist of 3M spray glue onto the mold surface, or whatever surface you are laying it up on. Then lay your FG onto it, pulling the cloth to remove the wrinkles. They do it all the time in the composites forum, building airplanes.

Don -

to further HEW565’s view - when using plastic packaging tape as a release for foam plugs, I use the very light spray of glue just to keep the cloth in place when brushing on/out resin. Otherwise the cloth gets “legs” and between stretching it, and having it “clump” in wrinkle - the glue keeps it in place - but still allows resin (epoxy) to cure and the glass to be removed. I second his recommendation.

What about the second and third lay?

It should work equally well there. I would rough up the hardened first layer to make sure the second layer adhered well.

Better yet, lay the second layer of glass on while the first is still slightly tacky, then you get great adhesion and don’t have to bother with the spray glue. much more than two layers, and maybe you would be better off with a thicker cloth. I like to use two layers of light stuff to try to prevent the thicker cloth from “printing” through, to show the weave in the finished paint job.

I have always had a problem using spray glue on waxed surfaces to tack the first layer down and as a rule only use it on Teflon release film or on surfaces prepared with a chemical release.
Have any others found the solvents in the spray glue (3M 77) attack the wax and create a “stick up”…??

I have only used it over wax/PVA molds. I’m afraid to do wax only! I have not had the need to use it over the Freecote treated molds I have…yet. I defer to Astute or look at: