Plexiglass crack repair

[984dm]

Hello fellow builders/flyers:

Asking for any wisdom from the group for how to repair a crack in the canopy? I had about a three inch crack that I'm fairly certain I successfully stopped from growing by drilling a hole at its end.

Has anyone used IPS Weld-On #16 Plastic Glue for Acrylic/Plexiglass to fill the drilled hole, and or to cover the crack? Or...any other recommended products?

What steps has anyone taken to repair a canopy crack that has lasted over time?

Thank you in advance for your help with this,

[GraemeSmith]

Section 3-24 in this document:

http://www.faa.gov/documentLibrary/medi ... w-chg1.pdf

[Kai]

No,

But the stuff I’ve using during my sailplane tech days for canopy crack repair, is something called Acrifix 192. It is specifically recommendet for crack repair in plexiglass (acrylic) sailplane canopies blown by a company called Mecaplex (Swiss, I believe).

It is a single component clear repair substance, which hardens with UV light. Subject it to sunlight or an UV lamp, it hardens very quickly. So fast, in fact, that small cracks form along the repair edges. No UV light at all, and it takes ages. During the hardening process, small bubbles tend to form in the substance- the only way I have found to eleminate them, is to puncture them with a sewing needle.

It is recommended to make a v-shaped groove in the plexi, and deposit the repair substance in this groove. This way, the groove repair is supposed to come out almost invisible to the eye, the ad says. The ad does not say anything about the substance shrinking substantially during hardening, so you need to make some sort of cofferdam with an eccess of substance to take this into account.

All in all it is a very time consuming and exhausting effort. The slightest anomaly and the end result is less than pleasing.

Sorry.