i got my dallas canopies from squadron the other day and was surprised to see that i had to cut it from a mold. im just now venturing into the realm of aftermarket so i was expecting something like what you would see in a kit.
i was at my LHS the other day browsing and come across what looked like sheets of plastic wrap. on the package, it had instructions on how to heat the plastic over a candle until it began to sag. they had a canopy from a kit pressed into some silly putty to hold it firmly and the silly putty was impaled on a piece of sprue or something. when the plastic was heated to the proper temp, it was lowered down over the canopy to allow to cool. when cool, it was a crystal clear, thin, excellent looking canopy! now im a rookie and would like to try this. how difficult is this process? please share your experiences with this or similar products as i would like to try this out. i have a F-16A that i would like to make a new canopy for as i cant find an aftermarket canopy for it. thanks. later.
I’d like to know more about that too, Saltydog. Seems to me that the clear plastic
would be in danger of picking up soot from the candle and getting discolored.
Maybe someone can fill us in.
You already have the basics in hand but instead of a candle use a 100 watt light bulb. What you are doing is using a male mold which will not give you good, crisp panel line detail. If you have a good eye for masking and painting this should not be much of a problem. One solution to this is to use painted tape or Bare Metal Foil to color your canopy panel frames. As with all new techniques - practise makes perfect.
thanks matt. later.
Salty,
I’ve used the “candle” technique many times with satisfactory results… the 100 watt light bulb would work fine too… never done it that way so I can’t speak from experience there. I’m currently doing a Modelcraft Cessna 172, and the windshield is way too thick, so I’m going to create another one using this technique.
I have used the candle to make all kinds of accessories, other than canopies, and localized a couple of tricks that can prevent frustration;
(1) Don’t use an ultra thin piece as your blank, or it will be too thin to work with after the mold (vacuform) is made.
(2) When heating the plastic, hold it parallel with your work desk and move it in quick circular motions over the flame in order to soften up the surrounding plastic (this prevents wrinkles between the heated and non-heated plastic)
(3) Before you remove the kit supplied canopy, use a permanent marker to trace out the cutting line.
(4) Before removing the mold, I will also lightly scribe the panel lines into the new canopy… this way, the original piece provides a solid background to work on.
Below is a link to an illustration I made of creating FOD covers for a 1/48 Chinook, using this technique:
http://modeling.gunsagogo.org/ec1.jpg
Like Swanny says… practice practice practice. [:)]
Take care,
Frank
thanks frank, that was a big help!! later.
Good tips, I’ll try them out. I’ve been holding onto some of those plastic sheets for awhile now.
I used modeling clay to fill the canopy you are making the mold of. you can cover it with thin plastic wrap to prevent it sticky to the canopy for easy removal later. I also put it in the freezer to harden the clay a little. I use a candle but will try the the 100wt bulfb trick.
What kind of plastic do you use? Thanks jkin1524.
You can buy clear styrene in various thicknesses at your LHS. But it’s easy to find plastic around the house that’s suitable. Look for the sort of crisp plastic that is used, for example, as the formed packaging of electric razors and other small electronics. You can use the back (unformed part) of the package.
As an alternative to the candle and 100 watt method, you can also hold it about two feet above the burner on an electric stove turned up to medium.
Good luck,
Mark
Thanks for that Matt. At a building supply store over here (Australia) called Bunnings they sell Plexiglass by the roll and they will just cut of how much you want. It is pretty thin so I think it might work. I will give it a try when I get nearer to finishing.
I agree with Frank -
A good source for thin, clear plastic is a 2 litre Coke bottle - it is a basic cylinder of flat sides with no other shapes - and it’s PETG - extremely clear and very easy to thermoform using the stretch-form method.
I have made a little frame from hardwood that has two handles on it and I attach a square of PETG to it using clothes pegs - and heat it over the flame on my natural gas stove top - it heats the entire sheet, allowing the plastic to basically “drape” itself over the male mold - this prevents excessive stretching which means VERY thin spots - which is NOT what you want. You want an even, uniform thickness throughout the entire canopy.
I used this method to make the windscreen on the Britten Motorcycle I posted the pics for - have a look - it’s in the automotive section (gasp - shock, horror - yes, they DO make models of things without wings).
Good luck, Chris.
you can use this technique with sheet styreen to. This way you create conversion parts such as ecm blisters, radardomes etc.
Thanks Frank I cant wait to try it.
Dang ! I could use my mattel vacufrom to make one. All I would need would be supplied thru the hobby shop.
This was not a joke either, if you knew what has happened to me, well, if you knew.