Gluing Exterior Panel Products

Polyurethane glue is good for mounting and laminating exterior-grade composite panels. May 5, 2007

Would polyurethane glue be the best to glue laminate to Extria for outdoor use?

Forum Responses
(Adhesives Forum)
From contributor F:
Laminate will not hold up outdoors.

From contributor M:
I have to disagree. Polyurethanes (Excel, Gorilla Glue, etc.) have worked well for us on exterior laminations. Regarding Extira, I would check with your supplier; there are likely a number of options.

From contributor D:
Well yes, the glue will work fine out in the weather. However, the plastic laminate will not work, and the allegedly exterior grade MDF will not last in an exterior situation. Remember, p-lam is made of kraft paper, and will take on moisture to the point of failure when in prolonged exposure. Put a piece of Extira in a bucket, then contact the manufacturer with your application. While you wait for them to eventually respond, the Extira in the bucket will have swollen from moisture. Look to yacht work and materials for precedent. So, while there will be some that will say you can do this, the question is do you want to? And why would you want to push such a marginal process into questionable areas?

From contributor E:
I've got about twenty Extira signs with unpainted backs that have been out in the FL weather for three years now, including three hurricanes, and they are going strong. I also have built and repaired yachts for over twenty years and have seen a fair bit of p-lam used in sportfish cockpits over the years on tackle centers. Seems to hold up fine for 8 years plus. By then they're usually remodeling everything it seems. It will dull some with the harsh saltwater environment and UV, but the material did well. We usually epoxied it to a marine ply substrate.