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Cracked Canopy Repair

Posted: Fri May 10, 2019 3:09 am
by SavageB
According to the manual, you can repair cracks up to 6". However, I can't seem to find someone that does this work.

I pushed too hard on my new bird and cracked the canopy on the pilot side. It's 2.75" long.

2018 DA42-VI

Any thoughts?
cracked canopy.jpg

Re: Cracked Canopy Repair

Posted: Fri May 10, 2019 5:02 pm
by Don
Brian, the first thing you have to do is drill a 3/16" relief hole right above the crack so the crack will not continue to travel.
Also, can you elaborate where and how you pushed too hard to crack the canopy so others don't do the same.

Re: Cracked Canopy Repair

Posted: Fri May 10, 2019 5:05 pm
by SavageB
Thanks Don. I have the instructions. The problem is I can't seem to find anyone who will repair it.

It has not moved since I cracked it. According to the repair guide (diamond), they now want a 3/32 hole. Everybody else says 3/16

Thanks!

Re: Cracked Canopy Repair

Posted: Fri May 10, 2019 5:14 pm
by Don
My company works a lot with acrylic for large flight simulation rear projection screens. Believe me, it will travel from the vibration of the engines and when you taxi. 3/16" of a hole is standard practice for this type of crack.

Re: Cracked Canopy Repair

Posted: Fri May 10, 2019 7:57 pm
by Colin
The canopy is over five thousand dollars. If it were my plane, I'd not spin the engines until I had done Don's suggestion.

Re: Cracked Canopy Repair

Posted: Fri May 10, 2019 9:38 pm
by Steve
There seems to be some diversity of opinion as to what size bit should be used to stop drill acrylic sheet. Anywhere from 3/32" (Diamond) to 3/16" (Don). Probably means that anywhere in that range would be OK. I would tend toward the lower end of the range, or maybe compromise on 1/8".

I have done a fair amount of work assembling acrylic structures (for the lab and display cases for my Dad's ship models). If that were my canopy, I would (along with my IA) stop drill (1/8"), glue the crack with some thin Weldon 4 adhesive (it is extremely low viscosity and will wick into the crack. Use a very small amount (they make applicators for this purpose), applied from each end of the crack, and allow it to cure. I would also run a small amount under the edge of the vent latch "socket", since the crack runs under that piece, and the rear edge appears to have disbonded slightly. If you get adhesive on the canopy surface, you can polish it off after it cures. Lastly, fill the stop drilled hole with clear silicone. Here are a few online references which you may find useful:

http://www.eaavideo.org/detail/video/4922730282001

http://www.plasticgenius.com/2009/03/re ... glass.html

Like Don and Colin, I would refrain from operating the aircraft until you make the repair (or at least stop drill the crack). Good luck,

Steve

Re: Cracked Canopy Repair

Posted: Fri May 10, 2019 11:01 pm
by Don
Quite frankly if, it was my 2018 plane, I would be calling my insurance company for a new replacement canopy. Even if you structurally repair it properly so that the crack will not continue to creep, the repair will still be visible and cosmetically detract from the appearance of the aircraft. That said, my friends say I am anal about keeping all my toys and stuff looking like new so it may not bother others as much as it would myself. Just sayin.

Re: Cracked Canopy Repair

Posted: Sat May 11, 2019 12:42 pm
by Colin
I have now learned that Don is one of the few people I would be happy partnering with for an airplane. I hate when things start to look bedraggled.

Re: Cracked Canopy Repair

Posted: Sat May 11, 2019 1:10 pm
by Steve
Colin wrote: Sat May 11, 2019 12:42 pm I have now learned that Don is one of the few people I would be happy partnering with for an airplane. I hate when things start to look bedraggled.
Do I detect a DA62 partnership offer in the works? :D

Re: Cracked Canopy Repair

Posted: Sat May 11, 2019 4:34 pm
by Lance Murray
Definitely stop drill the crack before operating. If you are in So Cal I have a guy that may repair It but no one will guarantee the repair or results. PM me and I can forward the name. But as Don noted above I would report this to the insurance company.

Remember that acrylic drill bits are different. Don't use a standard drill bit. It can chatter and make the problem worse. Acrylic bits are sharper at the tip.