Author Topic: Canopy (Read 4774 times)

Doug Moon · « **on:** September 12, 2012, 06:52:05 AM »

I am sure many of you have had this happen, Sun deformed canopy. It sucks!

Is there any way to get it back to its original shape?

I have a small depression in the canopy right near where it attaches to the front of the top block.

RC Storick · « **Reply #1 on:** September 12, 2012, 07:27:15 AM »

none that I know of.

Derek Barry · « **Reply #2 on:** September 12, 2012, 07:28:36 AM »

Don't paint them dark colors...

Derek

peabody · « **Reply #3 on:** September 12, 2012, 07:45:40 AM »

The plane is RUINED!
Do you have my address?

Larry Fernandez · « **Reply #4 on:** September 12, 2012, 08:43:20 AM »

Hi Doug,
I'm curious, did you happen to shoot any material with retarder in it over the canopy?
I shot the clear coats over a Still Stuka a few years back that was loaded up with retarder on the last two coats.
The canopy was a bit distorted a few weeks later as the dope shrank up.
Turns out the retarder softens up canopies and decals. It sucks to be stupid.

Larry, Buttafucco Stunt Team

Trostle · « **Reply #5 on:** September 12, 2012, 08:52:48 AM »

It sort of depends on what kind of plastic that canopy was made from. I have experienced two kinds of canopy deformation.

1. Some canopies that I have pulled over a form after heating the sheet plastic have deformed when they get really warm, like in the back of a car on a hot day. That plastic remembers it used to be a flat sheet and part of it tries to get back to a flat sheet which messes up everything. It will eventually resemble a pretzle if it gets hot enough. If that is what happened to yours, the only way I know to fix it is to replace it. Peabody would appreciate that before you send your airplane to him.

2. Is it possible that you did such a good job sealing your canopy over the cockpit that, again when it gets really hot (that old trick of being in a car on a hot day) and air pressure builds up inside the canopy. The canopy starts to think it can be a balloon and start to bulge. It will bulge around the painted strips of the canopy frame/wind screen. If you have just a small blister (as in a bulge), you might be able to take a heat gun or a monocoat iron and try to get that "bulge" to shrink back to its original shape. (You can work this stuff being very careful not to get the stuff too hot and wear some good leather gloves.) But it will not ever take its original shape back. So you might want to check out Peabody's address on this also.

2a. If air pressure building up inside the cockpit on a hot day is a problem, since your airplane is already finished, a small how (like a 1/32" drill) at the rear of the canopy next to the paint line would keep air pressure from building up.

In short, I do not think there is much you can do short of replacing it. And I have first hand experience with that and I know you can understand that is not a fun thing to do.

It will be interesting if anyone has any good ideas. I certainly do not.

Keith

Dave_Trible · « **Reply #6 on:** September 12, 2012, 09:18:00 AM »

Hi Doug! Well, I mold my own canopies but I haven't tried to fix one like this-but I'd sure try it. Mask the area around the canopy with foil to shield from some heat. Get a new 2 ounce syringe with hypo needle (Tractor Supply). Poke the needle through the canopy along an edge. Apply heat with a heat gun to the bad area while applying positive air pressure with the syringe. When the spot pops out remove the heat but hold pressure a little longer until it cools. Leave the needle hole so air pressure can equalize inside and out and maybe not do it again. Hope this works for you.

Dave

Steve Fitton · « **Reply #7 on:** September 12, 2012, 10:06:56 AM »

Stuff a whole bunch of M-80s in the pipe tunnel. The resulting massive overpressure will restore the canopy to the correct shape.....

Will Hinton · « **Reply #8 on:** September 12, 2012, 10:36:13 AM »

Quote from: Steve Fitton on September 12, 2012, 10:06:56 AM

Stuff a whole bunch of M-80s in the pipe tunnel. The resulting massive overpressure will restore the canopy to the correct shape.....

Peabody ain't gonna like that!

Doug Moon · « **Reply #9 on:** September 12, 2012, 10:52:16 AM »

Quote from: Dave_Trible on September 12, 2012, 09:18:00 AM

Hi Doug! Well, I mold my own canopies but I haven't tried to fix one like this-but I'd sure try it. Mask the area around the canopy with foil to shield from some heat. Get a new 2 ounce syringe with hypo needle (Tractor Supply). Poke the needle through the canopy along an edge. Apply heat with a heat gun to the bad area while applying positive air pressure with the syringe. When the spot pops out remove the heat but hold pressure a little longer until it cools. Leave the needle hole so air pressure can equalize inside and out and maybe not do it again. Hope this works for you.

Dave

Dave, thats a pretty cool idea for sure. In my case it wont work. Where the two top blocks meet under the canopy is a small gap to let the air equalize. It isn't sealed.

The deform happened on a Sunday Morning at about 8:30. It was around 85 degrees outside and the plane had been out for just a little while. I go to get it after a practice flight and get it ready for appearance juding. BOOM, there it is on the Sun facing side. A nice little indented area, about the size of a nickle. ARRRGGGGHHHHH DAMN IT!! 18 pointer GONE!!

The Steve Fitton option is looking like the way to go at this point. Well, not really but I sure felt like it then!

It is a painted Sig Canopy.

Mike Scott was thinking I could just tape it off, sand it down, and fill it with a little bit of bondo, sand it out and repaint it.

I think I still have Rich's address around here somewehere.....let me see if I can find it........

Dave_Trible · « **Reply #10 on:** September 12, 2012, 11:13:44 AM »

Well we tried. I'm just now going back to clear canopies after painting them on for a decade. Have to remember to cover them outside.....

FLOYD CARTER · « **Reply #11 on:** September 12, 2012, 11:23:25 AM »

What's even more disconcerting is when your pilot figure is painted with water-based "craft" paints, that don't stick very well to the plastic figure. Then, vibration causes the paint to flake off, coating the inside of the canopy with little bits of paint. No way to get rid of it!

On one of my planes in storage, a spider got into the cockpit and made a big web! I fixed that by drilling a 1/4" hole in the canopy and going in with a cotton swab on the end of a piece of coathanger wire to clear out the spider's effort.

Floyd

peabody · « **Reply #12 on:** September 12, 2012, 11:27:36 AM »

I'll wager Windy has. a video.......

Steve Fitton · « **Reply #13 on:** September 12, 2012, 11:32:32 AM »

Is this the Nats (winning) plane or the red Riff Raff you fixed up?

EddyR · « **Reply #14 on:** September 12, 2012, 11:46:09 AM »

A few years ago when I damaged a canopy landing inverted I cut it off 1/8" above where it joined the body and glued the new on on over the lip off the old one. I did not even need to repaint the edge.
Ed

Doug Moon · « **Reply #15 on:** September 12, 2012, 01:17:59 PM »

Quote from: Steve Fitton on September 12, 2012, 11:32:32 AM

Is this the Nats (winning) plane or the red Riff Raff you fixed up?

This is the winning plane.

I will get a close up of the offending spot later.

Bill Little · « **Reply #16 on:** September 12, 2012, 01:23:15 PM »

HI Doug,

Since it is a painted canopy, Mike's suggestion might be the best way out. I would treat it like a dent on a car fender. Maybe make a tiny hook and "pull" out the dent, refinish it and you're good to go.

BIG Bear
RNMM/AMM

Derek Barry · « **Reply #17 on:** September 12, 2012, 02:01:32 PM »

Clear canopy and cockpit detail...

Derek

Dick Pacini · « **Reply #18 on:** September 12, 2012, 04:52:53 PM »

My Free Spirit that I flew in the '73 NATS was a jet-style with a sleek canopy that I cut out of a long Sig RC canopy. I tinted it with Rit dye to have a reddish hue. The pilot was painted to have a Captain America look with tiny white stars all over the blue helmet. I wanted to have him smoking a joint and made a tiny cigarette which I glued into a small hole drilled in his mouth.

All was well until vibration finally took its toll on the glue. One day I was polishing the plane and had rubbed the cloth over the canopy a few times. Bingo, the static electricity caused the cigarette to jump up and stick to the top of the canopy. Nothing I did could make it drop out of sight. I cut the canopy loose in the rear and tried to lift it up high enough to remove the cigarette, but the canopy broke right across the top. I removed the joint and glued the canopy back together.

When ever I was asked why the canopy had a seam, I explained that one time during a bad hourglass, the pilot ejected and the canopy broke in the process. Those who had seen my hourglass understood.

RC Storick · « **Reply #19 on:** September 12, 2012, 06:03:01 PM »

Doug Moon · « **Reply #20 on:** September 12, 2012, 07:29:02 PM »

Quote from: Derek Barry on September 12, 2012, 02:01:32 PM

Clear canopy and cockpit detail...

Derek

I dont think I have the skills for that yet.

Doug Moon · « **Reply #21 on:** September 12, 2012, 11:25:40 PM »

Here are a couple of shots of the damage!

Sorry they arent very clear. No flash on this camera.

RC Storick · « **Reply #22 on:** September 12, 2012, 11:33:38 PM »

filler and repaint canopy

ash · « **Reply #23 on:** September 13, 2012, 04:05:39 AM »

If the canopy material is not permanently deformed into that shape you could try making a little handle/tab out of masking tape or perhaps something a little stickier and pulling the dent from the outside like this:

A bit of gentle heat might be tempting to try if all else fails, but it wil lbe hard to get it where it needs to be without causing distortion elsewhere. Aluminium tape insulation could help. Consider heat a last resort.

ash · « **Reply #24 on:** September 13, 2012, 04:09:06 AM »

PS, the heat approach might work better if you drill a 1/16-3/32" hole near the seam on the other side, somewhere less conspicuous, and poke a wire or stick through to push the dent out from the inside. Aluminium insulation and a bit of heat on the dented area might then be useful. Still a last resort before filling/refinishing, though.

PJ Rowland · « **Reply #25 on:** September 17, 2012, 04:10:25 AM »

Its fair to say If Direct sunlight caused the problem - Then my suggestion would be try Direct MOON light.

Don't under-estimate the power of a Moon.