Sika without fiberglass?

[Noah]

For those who used Sika on their canopy, did you fiberglass in the front intersection or did you strictly use Sika (no glass / epoxy)? Reports are that the Sika sands nicely and is easily shaped with 120 grit sandpaper which allows for a nice fairing at the front intersection; other reports are that the canopy gets a lot stiffer after the addition of fiberglass at the front intersection.

My concern is that the stiffness might be insufficient without the glass, and also that the strength of the epoxy is significantly higher than the Sika. Any comments??

[Radomir]

I did fiberglass on the front.. saw a plane that had Sika all around -- unfortunately, it didn't look good... Sika was painted over, and the paint cracked (exactly what I expected).. So I would not recommend Sika up front...

[Nehi]

Radomir;
I used sika on my canopy intending to paint over it but was concerned about what paint to use being the sika is so flexible. Should I decide to glass over the sika how many layers of cloth is recomended & how are the two properties compatable with expansion -contraction and adhesion ? thanks, Nevin

[lostpilot28]

I was going to only sika the bow and use the tabs with rivets under epoxy on the front. I ended up using screws because the 1/8th inch bead across the bow made the canopy sit just a hair too high.

Anyway, I think epoxy is the way to go around the front. Sika will soften if painted over, so don't paint it.

[DakotaHawk]

I did my slider using Sikaflex all around, with a custom-made fiberglass skirt. On the windshield, I Sika'd the plexiglas to the bow, and used epoxy filler and tabs to hold the plexiglass to the fuselage deck, then glassed over the epoxy to create the transition from plexiglas to deck. I didn't put any screws or rivets any where in my wind screen, and rivets only along the rear bow of my slider to hold the skirt on.

[N131RV]

Originally Posted by Noah

For those who used Sika on their canopy, did you fiberglass in the front intersection or did you strictly use Sika (no glass / epoxy)? Reports are that the Sika sands nicely and is easily shaped with 120 grit sandpaper which allows for a nice fairing at the front intersection; other reports are that the canopy gets a lot stiffer after the addition of fiberglass at the front intersection.

My concern is that the stiffness might be insufficient without the glass, and also that the strength of the epoxy is significantly higher than the Sika. Any comments??

On my bird, we sikaflexed the canopy and windscreen. I couldn't figure out how to eliminate the screws on the side skirts, so they are there,but no other holes in the canopy or windscreen.

Used a bead of sika to hold the windscreen in place (with clamps until it dried), then laid up fiberglass for a really clean and smooth transition.
At the rear, I put mold release on the fuselage and laid up fiberglass skirts directly onto the canopy. Very, very nice transition.

She'll be back in the air this week. Pictures to follow.

[dhall_polo]

I used the sika to form a fillet/transition from the plexi to the canopy frame. I applied superfil over this to refine and smooth the fillet.

No closeups handy, but I'm pleased with the result so far.

[DGlaeser]

I did most of the fillet with Sika, but added a couple of layers of thin cloth (the stuff called deck cloth) and filler for the final touch. Hopefully the cloth will prevent cracking - so far it has. Mine is a tip-up.

[BigglesRV7A]

I Sikaflex'd my RV7 tip-up canopy and elected to fibreglass the front transition. Despite using Sika 295 UV, with the plexi primer it still needs to be covered and protected from UV. Additionally it is near on impossible to sand Sika to a smooth finish. Across the rear edge of my tip-up (Fwd section) I fabricated a fibreglass shroud that snugs down flush with the rear section when the canopy is closed. This covers and protects the Sikaflex beneath these areas from UV light as well as stiffening considerably the entire tip-up. Happy to post pictures if someone is interested. Also wrote an article for local Aussie Sport Aircraft Assoc magazine if anyone would like.

Cheers and happy building,

Greg

[Noah]

Originally Posted by BigglesRV7A

Happy to post pictures if someone is interested. Also wrote an article for local Aussie Sport Aircraft Assoc magazine if anyone would like.Greg

Love to see 'em!

Dakotahawk / Lostpilot - What do you mean by "tabs"???

Dhall Polo- How will you protect the Sika from UV?