slider canopy weather stripping

[akorchak]

Does anyone have a good solution to seal an RV-6A slider canopy? I get water on the panel when I wash the plane.

[Bob Axsom]

(1) Install white "P" strip at the interface of the roll bar and the fiberglass layed up over the windshield that covers the windshield to canopy interface when closed. The canopy leading edge will seal against it when closed if done properly.

(2) Cut two ribs out of 3/16" bar stock that conform to the profile of the canopy deck and covers the space between the outermost protrusion of the canopy track extrusion back to the rear of the track. Rivet the ribs to the canopy skirt at the height above the canopy deck where the canopy track extrusion maximum otboard extension occurs (anout 1/2"). Use the pattern that you used to make the ribs to cutout flat rubber stock the is slightly larger than the ribs and glue them to the underside of the ribs so the rubber seals the parallel surfaces (rib edges and extrusion).

(3) Rivet upturned aluminum angle on the longeron from the rear of the side canopy tracks to the inside of the upper aft fuselage skin aund cut off those pait scraping canopy side skirt skirt skags as a better way to close the gap between the skirt and the fuselage aft of the sidetracks.

(4) Use 3M weather strip to glue on white "P" strip to the inside of the canopy skirt aft of the sidetracks to the rear center track. Set back the "P" strip so that it doesnt shjow but prevents aluminum contact between the skirt and the fuselage skin.

(5) Make a small aluminum hat to cover the center rail opening in the rear skirts and make a plug to slide on the rail with a rubber seal to close against the hat when the canopy is closed. Attach the plug to the bolt at the rear of the canopy with four individually tied pieces of nylon wire bundle lacing tape routed throug clear plastic sleeving to prevent snaging and breakage. You might make the plug out of balsa wood and use safety wire routed all the way through the plug and doubled back as the plug string tie points.

Implemented properly that will keep you and your cockpit very dry.

Bob Axsom

[tonyjohnson]

Bob,

Do you have any pics of that arrangement? I am trying to visualize it.

Tony

[Bob Axsom]

Part of it is hard to visualize (especially the side skirt ribs) but it is a very good solution. In 1996 when I went to one of the last training classes held by Van's Aircraft Ken Scott made it very clear that sliders do have problems with air leaks in flight. It took me 8 years to build the plane and I tried to make everything right the first time. Being forewarned of the problem I studied the function of the canopy for years in developing my solution. The problem is there are no two surfaces that remain parallel during the full range of motion of the canopy. I determined that the side canopy rail extrusions outer surface when viewed from above remain parallel to the canopy travel and if I provided a parallel surface on the inner skirt well above the canopy deck this could be used to seal the interface and it would not drag on the canopy deck when the canopy tilts down as it transitions from closed to open and back to closed. The details of implementation require careful methodical work but the results are well worth the effort. I may have to do a few posts to get this in. First the side skirt rib:








Bob Axsom

[Bob Axsom]

Bob Axsom

[tonyjohnson]

Bob,

Thanks for sharing your pics with us. I read an earlier post from you on this topic, but could not get it into my head how you did it. The pics help a great deal. I am doing my canopy now and I very much appreciate the information you are providing.

Please keep it coming.

Tony

[akorchak]

thanks Bob,
I'm mostly having trouble only with the top (roll bar) part of the canopy:windshield interface. I put some thin rubber weatherstripping on it, but now its difficult to close the canopy! Maybe I can form a clear gasket with caulking to compensate for the imperfect and irregular gaps?

[Bob Axsom]

With the leverage you have available in the latch it should feel snug but not difficult. The white "P" strip from aircraft spruce that I used in this area is hollow at the head of the "p" shaped material and the white rubber is so soft that it compresses to a very small size. Your approach my work but it requires some though on how you implement it. You do want some compression during closure to form a water tight seal, you do not want it to wear or fail after a short service life, you do not want it to be ugly. There will be some shrinkage with age (sort of like humans) that will degrade your seal.

I covered the leading edge of my canopy on two surfaces with aluminum tape (Actual aluminum with adhesive backing) from Aircraft Spruce. I wanted to cover the plexiglass to frame hardware (including fasteners and spacers that you put in there to allow the sliding part of the canopy to retain it's natural shape and conform to the curve of the windshield) and give a finished look to the front of the sliding canopy. I installed it very carefully to the outer surface of the plexiglass concentrating on a straight line at the trailing edge back just far enough on the canopy to cover the round frame tube (I understand that they are square tubes now) with the excess hanging over the front of the open canopy and provide a perfectly smooth tape surface with full area adhesion (no wrinkles or air pockets) on the outer surface of the plexiglass. Once that surface is done you can move on to the front edge of the canopy plexiglass. The idea is to fold the over hanging aluminum tape down so it also sticks to the front edge of the canopy plexiglass but it requires a little care and technique to do it right. The aluminum will stretch some but especially in areas where the canopy curves from the horizontal top to the vertical sides, a lot of slits need to be cut in the aluminum tape to alow it to overlap and lay flat with no wrinkles when it is bent down to cover and adhere to the front edge of the plexiglass. Cut off the excess aluminum tape after the front edge of the canopy is covered. A brand new very sharp blade in an Exacto knife worked very well for me. If mistakes are made it is not a problem since once you know what you are doing, it is relatively easy to take off and do again. I did not expect this to hold up long but I was wrong it holds up very well - after years of building with it inplace and three years of flying it is still like new. In anticipation of periodic replacement it told the painter in my 30 odd pages of instructions not to paint it but he did anyway. I expected the paint to scrape off but that hasn't happened either. Why is this important to you? Well, it is an additional gap reducing layer of material in the canopy to windshield interface.

Bob Axsom

[MrNomad]

Bob:

Be so kind as to identify the part number for p strip at Spruce?

Thanks.

[Bob Axsom]

Looking in the current catalog I believe it is 05-01200. Yes it is! I just went through my invoices and I bought a 17" rool on 1/16/03. It's on page 130 in the 2006-2007 catalog.

Bob Axsom