Canopy Scratches.

I was sanding around my plastic canopy with 220 grit, and accidently sanded a small patch on the canopy!

Is there any kind of polish for plastic canopies to remove scratches without making a bigger mess? I have some 2000 grit paper and some Happich SIMICHROME polish, (mostly used for metal), but I don't have any spare canopy material to test it on.

LAST EDITED ON May-10-06 AT 03:11 PM (CST)
 
I have some polish that works well to remove minor scratches. You can find this type of plexiglass polish at about any Motorcycle Shop. I got mine at the local Harley Dealer. Such scratches are common on the plexiglass windscreen of a Harley. This polish works great on your car or truck windshield to remove the haze that accumulates on the outside of windshields.

Frank Carlisle
proud member of R.C.C.D.

Floyd,
Don't take what I'm about to say as gospel until you get a few replies.

If I had a 220 scratch on my canopy I'd try filling it by spraying a few couts of clear on it then rubbing it out.

If I knew before hand that the clear would warp, discolor or distort the canopy then I would try sanding it out by going through the grits. 340-400-600-1000-1500-2000.

LAST EDITED ON May-10-06 AT 04:41 PM (CST)
 
You can pretty much take what Frank C. says as gospel. Make sure that you sand enough, but still just the bare minimum, to remove the prior grit's scratches. By the time you finish with the 2000 grit, it'll look fresh out-of-the-mold. Naturally the surrounding structure must be well-sealed, as it's best to use Wet-or-Dry paper, with water or a thin oil as the lube.

Tom Dugan's solution may work even better, but I don't know if you can try one and then the other if the first doesn't do the job.

On my last stunter, I was successful spraying Brodak clear over the canopy. Maybe that will hide the scratches?

I am still wary about spraying Brodak color on the canopy to simulate the metal frames. The masking tape job for these fine lines will be a challenge! If light coats of clear will work, maybe the color will also work?

>On my last stunter, I was successful spraying Brodak clear
>over the canopy. Maybe that will hide the scratches?
>
>I am still wary about spraying Brodak color on the canopy to
>simulate the metal frames. The masking tape job for these
>fine lines will be a challenge! If light coats of clear
>will work, maybe the color will also work?
>
>Floyd

Floyd,

do you know what kind of plastic it is? Sig plastic used to be butyrate based and you had to be real careful about spraying dope on it as it could soften the butyrate plastic and the canopy could collapse (don't ask me how I know). Sometime back they switched to a different kind of plastic that seems to be impervious to dope application. Don't know what it is but it takes dope real well.

If it's butyrate plastic and hasn't got any paint over it you should be able to smell a sort of "sewer" odor from it if you sniff close. If it doesn't have that smell you're probablyl good to go.

Might also tell us the source of the canopy. Is it from a kit? a commercial supplier? did you mold it yourself?

>I was sanding around my plastic canopy with 220 grit, and
>accidently sanded a small patch on the canopy!
>
>Is there any kind of polish for plastic canopies to remove
>scratches without making a bigger mess? I have some 2000
>grit paper and some Happich SIMICHROME polish, (mostly used
>for metal), but I don't have any spare canopy material to
>test it on.
>
>Floyd

Sand with 600 and spray Auto Urethane on the canopy, then sand with 2000 and buff. You will never know it was there. Trust me!

Robert Storick
AMA 12366
Saint Louis,MO.

Robert. Long ago, I learned to NEVER mix paint types. Starting with Brodak, I must finish with Brodak. Too much work already into this semi-scale Hurricane sunter to mess it up with paint.

LAST EDITED ON May-10-06 AT 06:21 PM (CST)
 
The urethane wont bother your paint job. If you dont trust it then sand the scratches with 400 and 600 grits wet paper, mask and spray canopy with a couple light coats of Brodak clear or whatever you used to begin with. The canopy will become bright and clear as new again. No big deal.
I always sand my canopies this way when finishing a ship. No problems in over 50 years of building stunt ships. SIG canopies are quite paintable for instance.

LAST EDITED ON May-10-06 AT 07:04 PM (CST)
 
Floyd,

Your best bet would be to use Micro-Mesh. You should be able to get it at your LHS. It's used by car modelers to polish their paint jobs to a mirror finish. Start with regular 800 wet sandpaper to get the scratches out, then follow up with increasingly finer grades of Micro Mesh, ending with 12000. If need be, finish by polishing with regular tooth paste. You should not have to use any kind of paint over it. I used this method on plastic model canopys with great results.

Hope this helps,

Gonzo

That Simichrome is great on car chrome. If you can stand the ammonia smell. Currell