Looking for options.
Are there any non styrene or acetone based sprayable primers that won’t react?
I have been using epoxy based sealants with less than ideal bond properties.
Any help would be appreciated.
I am laminating extruded polystyrene paneling.
Why not regular epoxy laminating resin? Or do you mean the PE resin doesn’t bond well to the epoxy?
Duratec Styroshield is made precisely for this if it’s available to you?
I usually would hot coat the foam with epoxy. I’ve also used foam sealers that are water based like the one Hanaldo mentioned. Or you can use latex paint, though that doesn’t bond very well to the foam but can work in a pinch.
I checked out all the info online and a hot coat of epoxy may be better than the duratec. The duratec says 20 mill working thickness. Also at 6lbs a gallon for my project it may be too heavy. I am going to try a few adhesives as a test. I’m going to see if a skin coat of mastic will do the trick and provide a decent bond to pe resin.
U could also use drywall spackle. Its what we use in the surfboard industry real easy to sand and finish
What is the bond like using the spackling? I just tried a pva glue to seal using peel ply to give a texture and it works really well.
$11 for a gallon of the pva glue is pretty cost effective. But it takes about a day to cure and sands like crap.
Mahalo.
What are u using as a topcoat or finishing coat? What process? We have used it in hand layup and vacuum bag with no problems. Next I will be using it in an VIP project for a Bodysurfing Hand plane.
Wet lay vacuum bag. Polyester resin.
I’m only using the polystyrene to strengthen the composite with shape than as an actual core. But I still don’t want disbonding if I can help it and also really don’t want water to be a bummer later.
I used 80 grit to rough the foam, blow and wipe with water. Then squeegee the pva glue on. Lay peel ply and let cure. The pva glue grips the foam well and the polyester grips the pva well too. Just wondering the cheapest best way that works.