Canopy Damage

There was a recent incident that has caused damage to the sliding portion of my RV-9A canopy. Apparently, one of the 6-32 retaining screws backed-out of the WD-640 canopy frame, this resulted in a crescent shaped portion of the Lexan separating in the area directly adjacent to the protruding screw when the canopy was shut (see enclosed photos).

Frankly, I’m at a loss regarding any repair options. Of course replacing the canopy is the worst case option, therefore I would GREATLY appreciate any suggestion/options regarding repair.


Thank you for your advice…

Well, assuming you still have that crescent shaped piece, it could be glued back in place using some acrylic glue or cement. Try using the search tool for some examples…

I’ve just finished repairing a not totally dissimilar crack in an RV-8, and will report on the process in the thread I started about it, just give me a couple of days.

To achieve a decent repair in your case, the canopy glass would ideally be separated from the frame, since providing space for the repair glue requires chamfraining the crack on the inner and outer side of the canopy. Not sure how the skirts are secured, but if you could effectively remove the screws and separate the canopy glass from its frame, an effective and hardly visible repair could be made, using for instance Acrifix or Weld-on glue.

Fill with thickened epoxy.
Mix some thickened epoxy and test a blob on an off cut of plexi, there should be no reaction but just to be safe...
Protect the canopy frame and gently rough up the chipped edge.
Slack the screws and slide in a piece of mylar or similar.
Protect around the edge of the chip.
Fill with thickened epoxy and sand to shape.
Re-tighten screws, drill & countersink missing hole.
Think about painting a stripe over the canopy frame.

Repair

If you don't have the piece that broke off then blend/polish the damaged area to remove any stress risers and drive on as is. If you have the broken piece then epoxy it back on.

canopy fix

I'd first try and smooth the area carefully with a dremel tool to prevent any stress risers in the future. Then fill the area with epoxy/microballoon mixture. You'll need to make it thick enough to stay in place but not too thick it has trouble bonding with plexi. Maybe use a alum piece (waxed) as a 'dam' to hold the epoxy in place until it dries. I'd then sand it smooth and paint a black strip along the entire canopy edge to hide the repair.

regular epoxy has a poor bond to acrylic, suggest you avoid that for this repair. West makes G flex which bonds to acrylic much better and there are several products made specifically for acrylic - weld on has several. West marine DOES NOT recommend their epoxy for acrylic - onlytheir G flex. A cosmetic targa strip with vynal would cover this nicely and add a little flare to the looks of the plane. WOuld need to fill the void with something first though.

I just noticed yesterday the corner of my tip up on the passenger side was missing. I have not found the piece. I was going to do a fiberglass targa strip but considering an aluminum piece instead.

The OP didnt say if he had his piece to replace. I agree with the others to dremel out any places that look like they could crack more and find a piece of plastic to fill the void. I plan to cut a piece to fit the missing one and use gflex to hold in place. Im still trying to decide if I want to overlap the rear glass a 1/2" or make it flush.

Good luck John on your repair.

Instead of smoothing with a dremel, try some dichloromethane, aka methylene chloride. It's a powerful solvent, and melts the surface of the plastic. I've used it to micro smooth edges where the material will be bent, like at the top of an early Kitfox windshield. Even with very good abrasive polishing, those bent edges tend to crack. A little in a shot glass and a few Q-Tips get 'er done.

Caution...do not breathe it.

I use G/flex a lot on my RV-3B. When I was planning to bond the fiberglass canopy frame/faring (non-standard) to the canopy, I learned that acrylic is not recommended.

Thanks to a tip I checked 2216 B/A epoxy and not only is it recommended for acrylic, but they even give a simple process. I used that and so far, haven't flown it yet, it's been fine.

Dave

Damaged Canopy

First let me say thanks to all those who responded. You input is much appreciated. Unfortunately, I neglected to mention that the broken-off crescent shaped piece was never found. So, a fix is going to require some type of addition/incorporation of a replacement piece... If possible?

Sent you a PM.

Plastic repair

You can also "replace" the missing material. Here is an extreme example.

https://www.polyvance.com/pfxcanopy.php-1

The product is sold on on their site and at Spruce:

https://www.aircraftspruce.com/catalog/pnpages/01-00544.php

Kevin