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echoooo

Member
In the last 2 years, I had problem with the Targa strip (weather strip) at the rear of the tip-Up canopy on my RV-7. It is a fiberglass one. It unglued twice on the right side of the canopy on a length of around 12-14 in. I glued each time with strong epoxy glue. Obviously, my partner in the plane and I were aware of the possible recurrence of this problem and took great care in opening and closing of the canopy.

This morning, at cruising speed, my partner lost the Targa strip. BTW, both corner of the canopy-plexi have broken (around 1in. by 1 in. triangle on one side and 1in. by 3 in. on the other side).

Is there a better way to replace that Targa strip than glueing it on place. We thought to install an aluminum one with glue in center and screw on its ends.

Any suggestions or comments.

Alain (QC)
 
Epoxy does not stick to plexy!

Hello Alain

Epoxy does not stick to plexy! If you scuff it well (60 grit), then you will get some mechanical "grip". But also then, the epoxy is more stiff than the plexy. After many thermal cycle or stress cycle, it will come lose. Also you are getting a crack prone plexy after scuffing with 60 grit.

Use Sikaflex UV295 with the recommended primer and you will not be able to tear it off! Place a few layers of tape onto your plexy where you want to glue the targa strip, this to simulate sikaflex glue during the fibreglas lay up.

When the epoxy is cured, take it of, cut and sand it until it is nice, then use primer and sikaflex to glue it.

In the process of gluing a canopy I made several tests. the strongest one was Sikaflex. But without primer, it will not adhere!
 
I removed every other screw when I layed it up, then countersunk and replaced the screws through the fiberglass and canopy.
 
N269SD said:
I removed every other screw when I layed it up, then countersunk and replaced the screws through the fiberglass and canopy.
Click to expand...

I wish I would have done this..... I've had a similar problem and have used a screw on both sides of the targa to secure it to the canopy
 
Thanks a lot guys for your answers. Not sure yet if I will fabricate a new Targa strip with fiberglass or aluminum, but I will sure use your recommendations to fix it on the canopy.

Alain
 
Before I fabricated the glass targa strip, I tried to make one out of AL... which I could not get to work.

As the canopy moves rearward, it tapers...I could get a great fit at the front of the AL strip, but at the back I had gaps due to the taper.

If someone had good metal working skills, I think you could use a shrinker to account for this taper, but that was above my skill level, so I just went with glass.

Jason
 
swisseagle said:
Hello Alain

Epoxy does not stick to plexy! If you scuff it well (60 grit), then you will get some mechanical "grip". But also then, the epoxy is more stiff than the plexy. After many thermal cycle or stress cycle, it will come lose. Also you are getting a crack prone plexy after scuffing with 60 grit.

Use Sikaflex UV295 with the recommended primer and you will not be able to tear it off! Place a few layers of tape onto your plexy where you want to glue the targa strip, this to simulate sikaflex glue during the fibreglas lay up.

When the epoxy is cured, take it of, cut and sand it until it is nice, then use primer and sikaflex to glue it.

In the process of gluing a canopy I made several tests. the strongest one was Sikaflex. But without primer, it will not adhere!
Click to expand...

This. I made a sample piece of canopy tube scrap and canopy trim plexi... and sikaflex'd them together. The contact patch is about 1.5" square, and I challenge anyone to rip them apart.
 
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