DaleB
Well Known Member
I bought a flying RV-12 that had some damage to the rear lower corner of the canopy on the right side. I intended to fix it later, when I had stripped the plane down for paint anyway. Over the past few months it's gotten worse, and I need to do something with it now rather than later. One crack is starting to propagate in a bad direction. Everything you see below is as I found it, other than some very cursory clean-up work.
Previous repairs seem to have been attempted with epoxy and hot melt. There was a triangular piece of .128 or so aluminum screwed in place of a missing corner (removed before these pics were taken, as was a loose piece of acrylic that you see missing). The whole thing was taped over to keep it from flapping in the slipstream. The good news is, the epoxy and hot melt didn't stick to anything and it's fairly easy to remove. The bad news is, stuff was still flapping in the breeze and cracks are getting worse.
From the outside, propped open an inch or two:
From the rear looking forward:
A view from the inside:
The pics look pretty ugly, I know, but it is what it is. Harsh lighting, and I haven't cleaned up all of the old adhesive and crud. One crack was stop drilled with a #40 bit, but a piece still came loose with that stop-drill hole at its apex. I have the piece, it's a clean break so it will go back in easily with the proper glue.
I can see a few possible ways to address this.
Previous repairs seem to have been attempted with epoxy and hot melt. There was a triangular piece of .128 or so aluminum screwed in place of a missing corner (removed before these pics were taken, as was a loose piece of acrylic that you see missing). The whole thing was taped over to keep it from flapping in the slipstream. The good news is, the epoxy and hot melt didn't stick to anything and it's fairly easy to remove. The bad news is, stuff was still flapping in the breeze and cracks are getting worse.
From the outside, propped open an inch or two:
From the rear looking forward:
A view from the inside:
The pics look pretty ugly, I know, but it is what it is. Harsh lighting, and I haven't cleaned up all of the old adhesive and crud. One crack was stop drilled with a #40 bit, but a piece still came loose with that stop-drill hole at its apex. I have the piece, it's a clean break so it will go back in easily with the proper glue.
I can see a few possible ways to address this.
- Replace the entire canopy and re-do all the fiberglass. Quite expensive, a lot of work, time consuming but a sure fix. I think it may be overkill though.
- Stop drill the new crack (5:00 from the screw in the first pic) with a #50 or so drill. Use a drop or two of Weld-On #4 in to close up all 3 cracks radiating from that screw hole. Glue the loose piece in place. Cut a piece of new acrylic to replace the AL piece that was there. Glue it in place, trim and polish. Flatten out the skirt as much as possible, and replace it when the plane is stripped for re-painting.
- Use Weld-On to repair the acrylic as well as possible. Either use countersunk screws with C/S stainless washers, or just remove the screws attaching the canopy to the rear of the frame, and re-attach it with Sika. Add a fiberglass or carbon fiber "Targa" strip across the back of the canopy to stabilize and cover everything.