Canopy Frame Seal

[SeanB]

Hello everyone,

I'm in the final stages of my tip up canopy frame construction. Initial cuts of plexi have occurred and the Big Cut is drawing near.

I plan to use the Bulb Seal from McMaster Carr on the deck plates.

Questions:
Does this seal end up being the same thickness once compressed as the 1/8" gap we use during building?
Can I go ahead and drill my side skirts before installing the seal?

http://ifly7.smugmug.com/Canopy/i-wGs3BKz/A

It seems this seal will end up elevating the canopy frame more than the spacers, then causing a larger gap.

Looks like Brantel ran into this issue:
http://www.vansairforce.com/communit...5&postcount=15

Thanks!

[bruceh]

I used the McMaster-Carr part # 1120A111 and it works great for this application.



Cut several short segments of this seal material and stick them on the frame as spacers before you drill the side skirts. You'll probably see that the material squishes down to just a hair over 1/8". Adjust the location of the side skirts to sit flush before drilling anything.

[Rupester]

... what Bruce said.

[SeanB]

Thanks guys. What about the forward skin for the tip up canopy? It's already a set distance above the longeron. Does installing this seal make that part lift up and create a gap? It also seems this increased thickness, compared to the 1/8" spacers used in the plans, would affect the canopy height at the Big Cut compared to the roll bar. Am I overthinking this? I tend to do that......haha.

[bruceh]

At least on mine, the gap opens up to more than 1/8" between the forward top skin of the canopy frame and the downward bend of the longerons and fuselage side skins. The bulb part of the weatherstripping still seals up just fine, but it isn't fully compressed like the aft part of the canopy frame rails.

[Smilin' Jack]

Sean,
Although 99.9 percent of the tip ups canopy sit on the side rail, I have seen so many with wide gaps along the sides and sealing them with 1/2 foam and totally dependent upon the gasket to keep the air out of the sides.

I used a little different approach.

My side skirts actually fit over the bottom longeron rail. I had to order another set of skirts but it work out beautiful.

I used a stop bolt on the rear of the tip up to stop the canopy as it goes down This is adjustable and allows the top Plexiglas to sit snug all the way around the rear roll bar.

My gap along the sides is sealed with a the 1/16 gasket material that Van's uses for the forward part of the canopy. I am guessing my total gap between the top canopy and the side rails is about 1/16 inch.

Yes this took a lot of work. used up 3 sets of side skirts.
I had to take this approach because who ever manufactured the quick
build fuselage did not bring the top rails over the side skin of the fuselage. So I ended up running a straight edge over the side rails and trimming the skin down 1/16 inch. so my side skirts go over the top rail longeron and butt up to the skin. Thus my side skin is flush to the canopy skirts.

I am not at home but in Houston, but would be more than glad when I return to send you pictures.

It made a tight canopy with no air rushing in. around the sides of the canopy or the rear.

Smilin' Jack

[SeanB]

Jack,

Thanks. I would really appreciate your pics when you have time.

Bruce.....I refer to your site often. Thanks for all the detail!

[Smilin' Jack]

Sean,
When I get home on the 7th I will dig out the photo's. Used to have a web site but Shutterfly re-did their site and mixed up all the dates and pictures. Fortunately I have a complete set of pictures and the builders logs.


Jack