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Building Tips and technical articles. => Building techniques => Topic started by: Mike Alimov on July 24, 2019, 07:36:07 PM
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Every clear canopy after heat forming has minor surface defects and distortions. What steps are needed to turn it into a perfectly optically clear canopy? I’m assuming sanding and polishing, but what would be the starting grit and the subsequent steps and materials? Should this be done only on the inside, only on the outside, or both? Are there defects that make some canopies beyond help, or can just about anything be polished out with enough elbow grease and patience?
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Every clear canopy after heat forming has minor surface defects and distortions. What steps are needed to turn it into a perfectly optically clear canopy? I’m assuming sanding and polishing, but what would be the starting grit and the subsequent steps and materials? Should this be done only on the inside, only on the outside, or both? Are there defects that make some canopies beyond help, or can just about anything be polished out with enough elbow grease and patience?
I would send the plug to Park Flyers. He pulls great canopies.
But that's me.
CB
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Nevr-Dull and elbow grease!
Regards,
Wolfgang
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I once tackled the plastic (plexiglass?) front windshield on my Cessna 172, which was pitted. I started with block sanding with 600 wet or dry, ending with 2000, 4000, and polishing with Maguire's "Mirror Glaze". Lots of work, but the results were perfect. The same can be done with any plastic canopy. I think the secret is using a block to sand, with plenty of patience. Can defects be detected from 6 feet away?
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Hi Mike;
There are all sorts of polishing kits for head light lenses on the market these days for when they get crazed over from road grit and dust and dirt. Those should work, or any other kind of plastic polish, like for what boat owners use for their wind shields, which are usually plastic of some sort, or aviation plexiglass. I think you would be impressed with how well toothpaste might work with a clean, soft cotton cloth and some elbow grease. A common practice among plastic model builders is to just buff the canopy of the airplane kit back and forth over the leg of your jeans pant leg! Pick out an expendable canopy to test the different methods on. I think you will find that they polish out fairly easily.
I'm still working on the pics I need to send you!!!
Type at you later,
Dan McEntee
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I wet sand with 2000 grit then shoot with clear. My last few planes were shot with 2 part auto clear, but dope works too. Good luck.
Don
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Sometimes the distortion is in the plastic itself. I don't think that type of distortion can be fixed.