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PU glue in stead of epoxy
Posted: Mon Oct 29, 2012 7:59 am
by pep
I have a background in blades for wind turbines made of glass fiber reinforced epoxy. For gluing structural PU is commonly used. The advantage is fast curing down to a few hours. Do you have any experience with PU as glue for panels?
Re: PU glue in stead of epoxy
Posted: Mon Oct 29, 2012 9:01 am
by Phishtech
What exactly is PU ??
Re: PU glue in stead of epoxy
Posted: Mon Oct 29, 2012 11:04 am
by pep
PU is polyurethane
Re: PU glue in stead of epoxy
Posted: Mon Oct 29, 2012 2:48 pm
by jem
For butt blocking it would be ok on a paddle boat but not as strong as epoxy.
But unless you can find a way to thicken it up for seam filleting, it won't be very useful. Thickened epoxy not only bonds the panels and fills any gaps but also, when applied correctly, provides a smooth transition between angled panels so the fiberglass can properly conform. PU can't, to my knowledge, be shaped and formed in this manner. Some PU glue expand as they cure.
So you'll need epoxy. And long as you are using epoxy, might as well get the best bond you can and skip the PU glue.
The alternative is "traditional" plywood-on-frame designs which I don't have but am considering adding a couple in the future.