Canopy Crack Repair Info

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1

Canopy Crack Repair Info

Posted: Wed Feb 14, 2018 11:40 am

by 8pointroll

So far I have been fortunate not to have joined the cracked canopy club but am in constant fear of becoming a member. Saw some discussion of crack repairs on the canard aviators group which had a link to the following product:

https://www.amazon.com/Weld-Acrylic-Pla … B0149IG548

as well as a link to an excellent canopy repair thread on the Vans forum: http://www.vansairforce.com/community/s … p?t=156810

I hope this is helpful to those of you in the club that I don’t want to join. Best Stuart

Re: Canopy Crack Repair Info

Posted: Wed Feb 14, 2018 5:50 pm

by Corby202

What a great write up. Thanks for sharing. I hope I never have to do it.

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“……link to an excellent canopy repair thread on the Vans forum: http://www.vansairforce.com/community/s … p?t=156810”

Unfortunately this link does not work - are you able to update?

Thanks :smiling_face_with_horns:

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Hi Skippy,

Unfortunately, I wasn’t able to find the original post referenced. It looks like the vans site also did some restructuring in the last seven years and I wasn’t able to find the original post. Sorry.

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I’m pretty sure the link is referring to Steve’s repair here from references in other posts: https://vansairforce.net/threads/crack-in-windshield.159097/post-1262512

There’s a number of other methods of repair on the Vans forum as well.

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This is a hairline crack, almost invisible from some angles. I have been recommended to use ACRIFIX 105.

I need to be sure of the canopy material . Its the tinted canopy supplied by Sonex - I have assumed that it is Perspex = polymethyl methacrylate.

Just found a reference on the Sonex web site Acrylic = polymethyl methacrylate

Pleas confirm.

:smiling_face_with_horns:

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Well some of us live & learn, others don’t. Such is life! ;

I got my ACRI-BOND 105 - be warned its heavier than water and pours very readily.

I have polished my canopy with Vuplex on numerous occasions.

Thinking it may be a good idea to remove any surface polish/dust residue, I wiped the crack area with isopropanol.

I think I may have been overgenerous with the isopropanol - some ran down the canopy, into the “sandwich” section of the frame.

Left the job to completely dry.

Came back 30 min later - Yea Gads!!! about 4 arcing cracks had appeared and the original had extended by another 20mm.

Canopy now not airworthy at all.

Have contacted Ian Linke (sailplanecanopies@ gmail.com) to discuss a new canopy.

In the mean time Ian has advised a temporary fix to get me back into the air. Fine fiberglass cloth, glued to canopy surface with superglue - he swears by this technique having used it to stabilise many glider canopies.

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Thanks for sharing, Skippy. Sorry to hear about the canopy. It amazes me how many liquids cause damage to the canopy and windscreen.

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Being a sailplane pilot, I have seen very many canopies with cracks, and a variety of repair techniques. Have never heard of using fiberglass cloth, but it makes sense. Typically they are stop drilled, something done to relieve the stress where the crack originated, then dremelling a small v-groove along/in the crack and using superglue and activator to cure it. Then sanding the glued crack line all the way up to 3,000-5,000 grit, then polish.

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Hi Kevin,

Thanks for the suggestion’s

The glass cloth/superglue is temporary to get me back in the air. Permanent fix will be a new canopy from Ian Linke .

The consensuses would seem to be that the Sonex supplied canopy is rubbish. There is just too much bending stress and the frame too flimsy. Most , if not all, will crack. :smiling_face_with_horns: