SikaFlex over alodine/PPG

[Flying Scotsman]

I'm creeping up on the canopy and within a few months, should be ready to cut and install it. I plan on using SikaFlex, but not sure which would be the best substrate. If I understand correctly, there are a couple of different primers...one for painted/powdercoated surfaces, one for bare metal, no?

I plan to paint the cockpit with a (very expensive) PPG automotive paint, colormatched to Van's powdercoat. It's a two-step process, with primer and then paint.

Everything that will get painted has (so far) been acid-prepped and scrubbed, then alodined. I'll do the same to the canopy frame. But should I go the next step and prime it, prior to bonding? (I'm thinking doing so will make final painting easier, maybe?). Or should I just leave the alodine and bond to alodined aluminum?

(Or don't even Alodine? ???)

After pounding a gazillion rivets, it's time to learn something new...and this definitely *is* LOL! So any help you can provide is much appreciated. I searched around, and read many threads and other builder's logs and photos and such...just trying to clarify things a bit.

TIA!

Steve

[Pilottonny]

Mine is steel! but I have a slider, don't know about the tip-up.

I grinded off some of the powdercoating, but made sure that the primer and Sikflex overlaps the powdercoating well, so there is no chance for corrosion of the steel frame, underneath the Sikaflex. Some builders just glue it on the powdercoating and theirs have not come appart so far, either.

Regards, Tonny.

PS use this information at your own risk.

[DGlaeser]

1) Painted the underside of the glaresheld and the canopy stiffener, but left all areas to be bonded bare metal.
2) Put a black matte vinyl cover on the glareshield, trimmed to match the fwd edge of the canopy.
3) Bonded the canopy to the bare metal. The bead at the fwd edge of the canopy went over the edge of the vinyl cover - made a nice fillet.
4) Painted the canopy frame, inside and out with the canopy appropriately masked.