In flight window loss

[kkmarshall]

I know it's impossible to see in photos and hard for me to tell what grit sandpaper was used,but there are sanding "scratches" in the fiberglass. I agree a good bond would not pull away cleanly like that,only the forward upper corner is well bonded and I tried chiseling it out with a gasket scraper. It's gonna take some work on that part. Contamination of some kind is my guess,whether wet or oily hands or whatever. Since it is confirmed that Weld-on was used,I am leaning towards using Lord from all the comments on the difficulty working with Weld-on. It is stuck really well to the plexi on the shards I have.

[snopercod]

If you don't mind a Lancair guy chiming in, that fiberglass (Looks like Vinyl Ester resin) looks shiny. That's not good. All I know is that when I bonded my acrylic canopy to the fiberglass frame, I was religious about prepping the bond area. First I cleaned the fiberglass with Prep-Sol, then sanded until dull with 80 grit, then cleaned with prep-sol again. I used Hysol structural adhesive to make the bond. Then I applied two bid over the joint on the outside.

[kkmarshall]

Glad for advice from anyone!

[Phil]

This isn?t exactly a one off. I know of 3 that have come out and one was actually on the ground. The belief is the hot sun reflecting off the unpainted wing popped the window out of the joggle as the window expanded.

So this isn?t a one-off as was previously mentioned. There is some history there and certainly more than the 3 I?m aware of.

That being said, there are several great adhesive choices out there that are more than adequate to hold a window in. But if the prep-work is sloppy they are all equally inadequate too. Regardless of which adhesive you choose, the quality of the bond is only as good as the prep-work performed on the mating surfaces and adequate mixing of the product.

[kkmarshall]

Interesting,Van's was not aware of any having come out in flight. I agree with you though, prep work is the key factor.

[RONSIM]

being "sucked" open as there was a definite venturi effect. I am sure the constant cycling of the pressure difference would eventually uncover weak bonding on the windows. (or poor door latching!)

Ron

[Aerosport1]

This might shed some light on adhesive. The aircraft was finished in January 2007. It shows airworthy certificate January 6 2007.
Lord adhesive for the window install was not being used till 2010 at the earliest.
JUST FYI
It looks like there was no sanding or prep done on the fiberglass.

[kkmarshall]

There are sanding scratches on the fiberglass but they are light,hard to tell what grit. I agree that prep seems the problem. I ordered some Lord from you,by the way.

[sblack]

Originally Posted by Aerosport1

This might shed some light on adhesive. The aircraft was finished in January 2007. It shows airworthy certificate January 6 2007.
Lord adhesive for the window install was not being used till 2010 at the earliest.
JUST FYI
It looks like there was no sanding or prep done on the fiberglass.

I think the original poster has said more than once that there are sanding scratches on the glass but they don't show up in the low res photos. I agree that it looks shiny, which is bad, but he says that is not the case. I agree that an internal joggle would be a better design as it would natural resist the pressure loads. That is an area of accelerated air so low pressure. Glad nothing valuable got sucked out!

[kkmarshall]

As for something getting sucked out,I wouldn't have believed it either,but I had a ball cap sitting on the back seat & it just sat there. Less wind in the cabin than in my pickup with the window down at 70 mph.