News:



  • March 28, 2024, 12:03:09 PM

Login with username, password and session length

Author Topic: Polishing custom canopies  (Read 1420 times)

Offline Mike Alimov

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 379
Polishing custom canopies
« on: July 24, 2019, 07:36:07 PM »
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?

Offline Avaiojet

  • 22 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 7468
  • Just here for the fun of it also.
Re: Polishing custom canopies
« Reply #1 on: July 25, 2019, 06:28:55 AM »
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
Trump Derangement Syndrome. TDS. 
Avaiojet Derangement Syndrome. ADS.
Amazing how ignorance can get in the way of the learning process.
If you're Trolled, you know you're doing something right.  Alpha Mike Foxtrot. "No one has ever made a difference by being like everyone else."  Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten. "No amount of evidence will ever persuade an idiot."- Mark Twain. I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.   Proverb 11.9  "With his mouth the Godless destroys his neighbor..."  "Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Offline Wolfgang Nieuwkamp

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 198
Re: Polishing custom canopies
« Reply #2 on: July 25, 2019, 07:46:36 AM »
Nevr-Dull and elbow grease!

Regards,

Wolfgang

Offline FLOYD CARTER

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4458
    • owner
Re: Polishing custom canopies
« Reply #3 on: July 25, 2019, 10:07:13 AM »
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?
89 years, but still going (sort of)
AMA #796  SAM #188  LSF #020

Offline Dan McEntee

  • 23 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 6824
Re: Polishing custom canopies
« Reply #4 on: July 25, 2019, 08:29:46 PM »
   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
AMA 28784
EAA  1038824
AMA 480405 (American Motorcyclist Association)

Offline Don Jenkins

  • 24 supporter
  • Trade Count: (0)
  • Commander
  • *
  • Posts: 348
Re: Polishing custom canopies
« Reply #5 on: July 26, 2019, 05:01:34 AM »
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

Offline Steve Fitton

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2272
Re: Polishing custom canopies
« Reply #6 on: August 05, 2019, 05:50:38 PM »
Sometimes the distortion is in the plastic itself. I don't think that type of distortion can be fixed.
Steve


Advertise Here
Tags:
 


Advertise Here