Finishing Kit

October 19, 2013

Canopy Guides - 6.0 hours

Well, it's been more than a year now since I made an entry in my Finishing Kit pages. Rather than put things in chronological order according to date, it makes more sense to me to put them in order like this. I've been jumping around quite a bit, working on this and that, and I don't want to put my readers through those gyrations. So I decided to present updates in the way that makes the most sense and easier to find things on my website if you're looking for something in particular. During the past year, I started on the electrical wiring, for example. Rather than jump around, I'll put all my wiring updates in a separate menu, and continue Finishing Kit items here. I'm nearly at a point where I'm ready to rivet the last top skin on the aft fuselage, and then install the rear window. Lots of exciting progress to report!

Meanwhile, after all the work I've done on the canopy, I have noticed that when it is lowered into place, it easily wiggles from side-to-side a bit. There's just no way to avoid a minimal amount of flexure in the structure. It's good and solid when it's all the way down and latched and locked in place. But this can present a real problem if the lug on the bottom of the frame is pushed over to the side just enough that it misses the hole in the canopy deck and lands squarely on it. This would cause dents in the canopy deck, or worse! So I noticed that other builders have been fabricating and installing these simple canopy guides for their tip-up canopies.Vans has one on their factory demo plane, too. I decided it was time to do it on mine, too. I've noticed some builders install a double-guide on each side. But I don't see the need. If one side is over too far, these guides will make the canopy go the right way. The canopy lug slides along the guide, straight down where it's supposed to go into the hole. It's a foolproof way of gently guiding the canopy into exactly the correct positioning, as the canopy is lowered.

So I took some Delrin blocks and carefully cut, drilled, countersunk, and fabricated them into these guides. Then I worked to install them on the roll bar. It took me a lot longer than I thought it would (seems to be the theme of the day, these days) but I'm pleased with the results. It should work real well, and it looks pretty good, too. I used pieces of aluminum scraps with some nutplates riveted on, to go inside the roll bar, for the screws to go into. They will never be seen. It will be easy to take these off or replace them if it's ever necessary.

Here's the one installed on the right side:

And here's a picture of the one on the left side:

Here's another interesting item. While digging through my stuff in the shop the other day, I pulled out my leftover SikaFlex supplies from my tip-up canopy job that I did back in April, 2012. That was over a year-and-a-half ago. I used less than one tube of Sika 295 UV on my tip-up canopy. The leftover cartridge has about 2" of material left in it and has been sitting on my shelf for 1-1/2 years. I figured it would have cured hard as a rock a long time ago. It expired in Jan 2013, 10 months ago. So out of curiosity I got out my tin snips and cut open the cartridge. Imagine my surprise when I found the material inside as soft, fresh-smelling, and gooey as brand new! Next, my can of Aktivator 205 (Sika Cleaner) was on my shelf, too. It's more than half gone, and it expired 11/10/2012, almost a year ago. Finally, I have a half-can of Sika Primer-209 D that a local friend gave me recently (I sent my original leftover Primer to a friend in California about a year-and-a-half ago). The can I now have expired in May of this year, 2013. So it's almost 6 months past expiration.

So I thought, what the heck, I'll see if this stuff is still any good. These materials are WAY out of date. This will be a good experiment. So I grabbed some scrap pieces of aluminum and plexi, and scuffed them up just like I did the canopy parts when I did it a long time ago. I used the expired cleaner to clean them. Waited 10 minutes, and applied the expired primer. Waited 30 minutes, and smeared some of the expired Sika on with a popsicle stick, and stuck them together. I left this sitting on my shelf for a few days to see if it would cure. It did. It's a little over 1 square inch in size, the black Sika under the plexi.

So what's the bottom line? You would not believe how strong this bond is!! I have used all my strength trying to pull these parts apart, and I can't do it! Mind you, again, this is using materials that were LONG expired when I put them together here. And again, it's only about a square inch of material. I have had more fun with this... especially with skeptics. I have taken it to chapter meetings, fly-ins, and showed it to friends and visitors who come to my shop. In every single case, I challenge them to see if they can pull it apart. I've handed this to some dudes that are much bigger, beefier, and stronger than I will ever be, and nobody can pull this apart.

Now, I'm not suggesting anyone should use expired materials on their RV. I just thought you'd like to know what I learned here. How much better is the fresh stuff? AM I SOLD ON SIKAFLEX, for my canopy and window installations? I love this stuff!

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