Finishing Kit

January 26, 2012

Final Canopy Trimming and Deburring - 3.0 hrs.

January is racing past, and I've been out of town a great deal this month. In moments here and there, however, I'm still making some slow progress. I pulled the canopy off the plane again after carefully noting where the aft end needed a bit of final trimming to make it conform to the line drawn over the roll bar back when I first started working on the canopy. The canopy can actually be nudged slightly forward or aft at this point, so the critical part isn't an exact length, but getting the canopy's aft edge straight, smooth, even all across, and matching the line. Up to now, it had just been rough cut and rough deburred.

I don't have a lot of pictures to show for this work. It's not exciting at all, and it's time consuming to uncleco the side skirts and take them off, pull the canopy off and file a bit on the plexi, put it back on the plane and cleco the side skirts back on, check the fit, and then do it all over again. I probably went through this process 8 or 10 times before finally having the aft end of the canopy finely trimmed to match the line on the roll bar. Once again, I used my vixen file for this work, always carefully pulling it toward me and gently shaving off tiny amounts of plexiglass at a time. It works marvelously well. Then deburring the edges, at least roughly deburred, before putting it back on the plane to check the fit again. This process left a very flat edge, meaning it fits the line over the roll bar very accurately.

Here are the tools of the trade for the final deburring work. Not shown is the vixen file. I had a shot of it and my pulling technique on an earlier page. When the fit is finally right, the hand scraper is used first. This is a nice tool! I started with the "V" in the middle to remove the sharp corners of the plexi all along the edge. Then, you go to the curved openings to sort of round the edge. As you pull it toward you, it takes the plexi off very nicely with kind of a squealing sound. Then I have sanding blocks. I started with 150 grit, then went to 220. I used the next two gray-colored sheets without a sanding block, just the paper and my fingers. I have 400 grit and 600 grit to finish it. When you're done with 600 grit, the edge is almost polished. It's very nice, and I'm calling it done. I may get some extremely fine grade later, maybe 1500 grit or something, and see what that does, but I honestly think it would be overkill.

UPDATE: Much later, when my canopy was all finished, I discovered some products made by Novus. There are 3 of them, actually. Number 3 is a heavy scratch remover (I haven't tried it, don't have any). Number 2 is a fine scratch remover, and number 1 is a spray plastic cleaner. I bought #2 and #1, and love them both! I found that if I get a fine scratch in the plexiglass, I can actually sand it out, using the sandpapers shown above, and then using Novus #2 and a soft lint-free cloth, rub it with this compound until all traces of scratches are removed. You are left with clear, scratch-free plexiglass again. It's great stuff! I highly recommend getting some of these products and keeping them on hand. I found mine at TAP Plastics locally, but they are also on Amazon and other online retailers. I'm mentioning these products here because I used Novus #2 on the edges of the canopy after sanding as noted above, and the finished surface is completely polished out. Very nice!

It's hard to see in this picture, but if you look close you can see parts of the black ink line drawn on the masking tape over the roll bar months ago. This canopy now fits as well as I can possibly make it. It's ready to Sikaflex in place!

Before I do that, however, I'm wondering if I should do the final fitting and deburring on the rear window, so they can both be sika'd in place at the same time? I have at least one friend who's waiting to do his for that very reason. Part of the thinking, I believe, is that once you open the sika materials, you should use the primer and the adhesive in a reasonable time and not let it sit around, or you'll lose it. I'm going to have to research this some more. And then, obviously, before the rear window is put in, the last aft fuselage skin has to be riveted onto the fuselage. And I don't want to do THAT until I do the wiring runs through the fuselage. So it may be a while before the sikaflex is applied to finish this whole thing. We'll see. It also occurs to me that I want to finish painting the canopy frame with my interior JetFlex paint. This has to be done before the canopy is bonded to it. And the front "dash board" needs a nice flat black finish applied as well. So I have some work to do before bonding the canopy to the frame. But at least I can call the fitting portion of the job DONE!

<< Previous | Home | Next >>

Contact me: swayze "at" (replace "at" with the @ sign... no spaces... you know the deal)