Neville,
Depends on what the canopy is made out of. Some canopy material won't accept dye. For those, I've used candy concentrate colors and shot the inside of the canopy with it until I got the tint I wanted. For canopies like the one I used for this plane (made of PET not PETG), I used Rit material dye in warm (maybe 100°) water. Let it soak for about 20 minutes checking the color every 5 minutes or so until I either get the tint I want or the canopy gets as dark as it's going to get. In this case, I got what I was looking for but that's probably because I was using a dark brown dye. I did a canopy that was dyed yellow and had the sucker soaking for almost an hour and still didn't really get it as dark as I wanted.
One thing to look out for, though. Don't get the water too hot or PET will start to curl up. Hotter doesn't really help all that much anyway. Warm will do it. Say 95°F to 110°F.
Eric,
Yea, I know what you mean. But truth is, I just couldn't stomach a Candy Fungus Green plane.
I probably would have put up with the surface flaws if the color had been OK. But the combination was just too much. So I figured that hey, sanding it down will kill two birds with one stone. I think I took a picture of the original color. I'll have to post it and you'll see what I mean. So by the time I got to that point I thought, well, I've done all this work to get a decent surface, I really can't put up with the substandard canopy and cockpit. The surface of the fuse under the canopy just had too many flaws, the color wasn't going to work with the new base color and I had that fog spot on the inside of the canopy, though considering the theme of the plane, smoke in the canopy probably wouldn't have been noticed.
So, now it's all prettified and ready for base color. There are a couple of spots that I'm concerned about but I'll have to see what it looks like after I shoot color. I plan to shoot a thin coat of base color and let it dry for a day then inspect. Hopefully, I can just go ahead and shoot a medium coat of color after that. If those couple of spots on the fuse I'm worried about end up sucking bad, then I'll see what I can do about fixing those then reshoot the area thinly again then go with the final color coat.
Man, when you get to the point where you're running your finger over the area over and over and you can't decide if it's a problem or not, you really need to just give up and shoot paint.