Duckworks lens poor fit issues

[FlyGuy65]

Trying to install DW on 2003 vintage RV7. Made the cut out in the le - easier than anticipated. Cut the plexi - easier than anticipated. First lens - ugly gap. Figured I just didn't fit it right. Second lens, careful as I could be, pressed firmly into leading edge - still ugly gap with final install (with added bonus of a crack...) As someone pointed out in a previous thread, if it's not the right shape, it's just not going to fit.

Any ideas for either getting a better fit, or another lens kit that will fit in the hole from the DW kit? The le has not been attached to the spar yet. I'm torn between "fill the gap with clear silicone and 'build on'" versus scrapping the le and building another now while it's easy to do.

[Jvon811]

I'm in the same dilemma you are. I ordered replacement lenses for the 20+ year old originals that were cracking and hazing in my -4. I purchased them about a year ago. I noticed the replacements were quite a bit thicker (almost double) and didn't produce a very tight fit.

I gave in and order another replacement for the replacement about 3 months ago. I haven't installed replacement #2 yet, but just out of the box, I've noticed that #2 lens is thinner and on par with the thickness of the original lenses. It might make all the difference in getting it to fit. I'm wondering if there was a batch that was too thick/wrong shape that went out.

[Desert Rat]

I just went through this. Had a set of completed wings from 2007, ordered duckworks lenses, followed instructions with the tape handle method in the instructions on the first one and wasn't happy with the results. It was flush top and bottom, but there was a gap right at the L.E.

On the other side, I just reached through the lightening hole in the end rib and pushed it in from the back side while I was drilling the pilot holes. Worked out better for me even thought instructions specifically tell you not to do it this way.

I reordered a new lens and re-did my first attempt using the same method and got better results.

In my case, the cutouts were oversized a little to clean up an old home grown installation, so that may have made a difference for me.

If you absolutely can't live with it, there's a guy who makes an alternative. The name of the company is Big Sky Robotics. I have no personal knowledge of the company or product, just saw it on one of the RV7 facebook groups.

FYI- you mention clear silicone as a possible solution. That stuff is the devils brew as far as getting paint to stick.

[FlyGuy65]

I pushed like heck from behind on the second attempt - still not flush. Also, if the lens has to be coerced into the le, would that create stress points where the screws are, and lead to future cracks?

My lens is approx 2.5mm / 0.10 inch thick - is that the thin or the thick version?

[Desert Rat]

Thats the same thickness I have.

Hey, I don't want to give the impression that mine are perfect. The tape method gave me a gap of about 1/8" at the L.E. Pushing from the back got them a lot better, but there is still a gap of about 1/32" at the apex of the L.E. Assuming that it will all be pretty uniform at that depth when I get the gasket material in there that came with the kit.

As far as cracking, I guess time will tell. If they crack, I'll concede that they need to be looser in the hole, redo them and run a fillet of pro seal around the seam. We used to do that on the jets I worked on. The nav light blisters were glass and frequently didn't fit the tips quite right.

[Doug Rohrer]

I got my lenses to fit better by applying heat with a heat gun to slightly soften the material while pushing it into the desired shape. Definite improvement but still not perfect. Just be careful not to overdo the heat and warp it.