West System GFlex 650 & 655

[Jesse23]

Anyone have experience with this West product? It’s a 2 part epoxy that is @30% more flexible than standard West epoxy resin. It also has vibration absorption and pressure properties for strength.

Thinking about using the GFlex 655 (toothpaste consistency) for the paint cracking at the top of the windscreen where a lot of RV 10 users have experienced. It’s usually just the paint has cracked. The windscreen is not going to come out.

Thinking about 1/4” to 3/8” wide (no filler) patch. Sand and paint.

Any thoughts?

 

[F18Sailor]

I’m a pretty big fan of the G/Flex 655 product, especially where dissimilar materials come together. I used it to repair some minor separation of the fiberglass windshield frame from the fuselage sides on my 9 and it’s held up. For the area you are describing however I might opt for an epoxy fairing compound-I tend to make my own with resin research composite pro 2050 and microballoons, though totalboat makes a good product. The reason being is the sanding required; g/flex is pretty tough and not all that easy to sand. I’m also not a fan of the West Systems products in applications where paint or gelcoat are being applied. It amine blushes badly, meaning you need to do a good job sanding then cleaning (acetone+IPA) to ensure a good bond with the paint.

 

[David Paule]

Those epoxies are structural adhesives, not caulks. They don't stick well to acrylic, either. I recommend something else.

Dave

 

[Richard Connell]

Based on my experiences in a marine environment (and the inability to get the right weld-on down here) I used the Gflex to do all of my windows and windscreen.
I used an acrylic primer and also glassed over the joints.
That was about 6 years ago. No sign of any movement anywhere. Paint is perfect. Plane is hangared but probably spends about 3 weeks a year outside. So it’s been exposed to some decent thermal cycles.
Just one data point.