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prkaye

Well Known Member
So I installed the Duckworks light on my left wing last week. Pretty happy overall, except for one thing. The plexi is not tight up against the leading edge at the very front. The skin has a tighter bend there than the plexi. The gap would allow water to enter the landing light bay if it were pouring down the leading edge. I'm not one to get bent out of shape about the cosmetics of this, but want to do something to keep water out and avoid aerodynamic problems. RIght now I'm leaning towards using some proseal to fill this gap.
Comments? Anyone else experience this with these lights?
 
Phil,
I put a ductworks in each wing and have a very tight fit, although it wouldn't be watertight. In the instructions I believe they recommend using 1/8" weatherstripping just inside the opening as a seal. I plan on using it in the final assembly of the aircraft. I think you would like easy access for bulb replacement/adjustment, so I wouldn't use proseal on the lens. If your not happy you could always order a new lens and make it more pliable by heating it. This would allow it to conform to the leading edge a bit better.
 
Hey Phil

The Duckworks kits have been around a long time, like before the -9 was conceived, so I suspect that the curve of the plexi is designed for a rounder leading edge.

You could try taking a heat gun to the lenses and curving them a bit more.

My $0.02

Cheers
 
I used the weather-stripping, and the plexi is tight except at the very front. I used their "tape handle" method to pull the plexi up against the LE while marking the holes. For the next one, I think I'll try not installing the light mount until after I have drilled the plexi, so I can have a helper reach inside from the rear and push the plexi tight against the LE while I start drilling.

I started the drill for all the holse with the plexi held like that, and then finished the holes with the plexi on the workbench.

It's pretty close, and at this point I don't think it's worth getting a new lense... another alternative to sealing the gap could be some outdoor transparent caulking. Could be easily re-applied after a bulb change.
 
I put a drop light under the lense to warm it and it fit pretty well. I did use the weather stripping they supplied, but would use some kind of paintable caluking if I were to do it again. I'm sure Proseal would work, but you might want to use a little bit of some kind of release agent on the surfaces. That way you could get in to change bulbs more easily.

Richard Scott
RV-9A wings
 
There is a proseal that is designed for removable panels. I dont remember what flavor it is off the top of my head but Im sure some search engine work would get you close. This type of proseal is weather tight but will release resonable well. If I needed in every day I would not recomend it but for light changes..........its an option.
 
what about regular hardware-store outdoor caulking for sealing up things like this, where you only want an air/water seal, not structural rigidity? Is there a good reason not to use this?
 
Phil, I've tried experimenting the last couple of days and am going to try this for myself.

I bought some clear 732 RTV. Bent a piece of metal slightly so that "voids" would form between it and a flat surface. I then applied the RTV. put wax paper over the top and clamped a piece of plexi to it. This is to simulate putting the RTV on the inside of the wing lens opening, putting wax paper over it, then clamping in the lens. I let this sit for 36 hours. When I unclamped it and pulled the wax paper off, there was a very nice "gasket" left on the metal; flexible and compressible. Furthermore, it adhered to the metal nicely without being permanent; I could actually pull it off, then rub the remaining off the metal with my fingers.

I'm hoping this will give me a nice gasket without the bulk of the foam strips supplied with the Duckworks kit.

One thing I haven't determined. What is the affect of this arrangement for a prolonged period of time on hot days. Will it heat into a seal, making it difficult to get the lens off next time I need to change a light bulb? Don't know that.
 
Pam as a release agent

I just bought some CS3330, which is the access panel type proseal (I think it is red). From what I understand, it is only a little bit less than impossible to get off, so I don't think it would work to seal lenses. I plan to use it for the fuel tank access panels.

The nice lady at Sealpack did tell me that you can use Pam (the kitchen spray) as a release agent for Proseal. That might work. I also bet Proseal might not stick to parchment paper (used in the oven for baking)

I hope you guys figure this out before I need to do my Duckworks!

BTW - Vans is like way cheaper for a quart of regular Proseal than anyone else (like A/C Spruce, Sealpack, etc.), about $40 vs. $60+. The 6oz tube of CS3220 was about $30!
 
I'd give Duckworks a call. I've spoken with him and I believe he fits the lens pretty precisely to the airfoil of the specific model. You may just have the wrong lense or a bad one slipped through Q/A.
 
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