Jet Canopy

[wardebest]

Help,
I am somewhat new to the hobby and am trying to make a series of jets, but I am running into real problems getting the canopies to sit right. Mine are a total disaster. Does anyone have any useful techniques? Do you stuff them with cotton balls? Any advice is appreciated.

Ward

[peter taft]

Canopies can be fun but often aren't. Can you please state what you are doing...i.e What you are using, how you are trying to put them together..etc etc. Some pictures of your attempts will help us to help you ! Thanks.

[wardebest]

Here we go- this is a Fiddler's Green F-4. While putting the canopy on it seems to buckle and come detached. I used all the tabs and such as it came with the model and did not add any extras. I form the canopy first then attempt to glue it on. I have issues getting the curve of the canopy to match the body of the aircraft. So then I try to modify it from there. Then I hack it all up and print out another one and start over. I also have an A-4 Skyhawk that I did in a much larger scale which was a real disaster.

[Knife]

After gluing the canopy together (always glue from the middle out to the sides), try gluing a thin sheet of paper to the inside of the canopy to reinforce the joints. Thin paper such as regular printing paper works great. Once dry, this should keep the canopy from splitting at the seams and buckling. I use a ball bearing glued to a stick and rolled around the inside of the canopy to help round out the shape.

Good luck and keep practicing.

[airdave]

What scale is this?
What weight is the paper/card you are using?

Maybe your problem is too thin/light paper.
Try using cardstock.
Unless its really small scale...smaller than 1/72, say
...then you might try a little heavier paper than regular copy paper
(maybe 30lb or so. Regular paper is usually closer to 20-24lb).

Form and assemble the canopy carefully...then coat the inside with PVA glue.
Once its dry, it will be a bit more rigid.

Install it with a delicate touch.
If it doesn't match the shape of the aircraft, don't force it.
Maybe its not a well designed model?
FG kits are nice, but they aren't particularly accurate.

[Erik Zwaan]

Knife's comments are very useful and should do the trick.

If the models have a cockpit interior and you want to make a clear canopy, the vacuum technique yields the best results. It takes practice and you need a vacuum box but this is a tool you can build yourself.

On YouTube, check out tutorials and search for "vacuum forming canopy" and "vacuum box". That's also where I got my info from.

Success!

Erik

[airdave]

Vacuforming is a great idea to make more realistic canopies that are see through.
I agree with Erik.

But, as Erik says, more for a plane with a cockpit...
for a model that has no cockpit or interior, it can sometimes be less attractive than the paper canopy.
And, you still have to deal with the paper canopy frame.
This may be a challenge for a beginner, especially on a very small scale model.
Not to mention all the work involved in building a vacuforming machine, and the work involved in making a plug/mold.

Theres also something to be said for learning the basics of paper work, before running back to plastic.
I personally think its a good idea to learn how to assemble the paper canopy on this model
and learn more about paper building techniques that can be applied to other areas.

.....
Looking at your F4 photo, I think I see two problems with your building approach.

When making sharp angle folds, you need to prescore the card so it bends cleanly.
Find a dull, but thin tool that can leave a scoring impression (not a cut).
Use a straight edge wherever possible, and prescore anywhere that has to be folded precisely.

If a softer bend or curving fold is necessary, use a wooden dowel or some other cylindrical item of the correct diameter.
Your knife handle, if its round...paintbrush shafts...markers and pencils.
Anything to give your card a smoother curve without the creases and buckles you will get from freehand forming.

For that canopy, I might assemble the parts and once the glue is dry,
I'll use a wooden dowel with a rounded (sanded) end,
to burnish and shape the inside of the canopy, making it rounder and smoother.

The type of paper/card you are using is still important.
Cardstock will hold its shape better and will bend and form without wrinkling as easily,
but can be harder to shape at very small scales.
Some people prefer lightweight paper for small parts and smaller scale models.

[cfuruti]

Regarding a previous reply: instead of simply coating the inside of the canopy with glue, I'd glue strips of paper (first along glued edges for reinforcement). This will reduce the risk of deformation caused by oversoaking, especially with thinner paper. Also, a few layers of glue+paper make very strong structures.

Originally Posted by airdave

For that canopy, I might assemble the parts and once the glue is dry,
I'll use a wooden dowel with a rounded (sanded) end,
to burnish and shape the inside of the canopy, making it rounder and smoother.

I've rounded parts using surfaces like kitchen spoons (the best size depends on the scale and curvature of your part) as improvised dapping blocks: with a fingertip, firmly hold the inside of the part against the concave side and slide it around in circular motion (finger+part move together). Also, turn your finger back and forth like when taking a fingerprint.
The sliding also seems to flatten the paper fibers, giving a very smooth surface finish.
An advantage of this technique is that it works even if the part's inside is irregular due to tabs or reinforcement strips. It probably won't work on laser prints: I guess ink will flake or lose its shine.

Sigh, it's a long time since I have built something worth of note, but here's an old example:
http://www.papermodelers.com/forum/260721-post10.html

[Rubenandres77]

Try also gluing the edge of the paper. Do not force it.
The front and back of your canopy looks crushed.
It certainly allows for a bigger contact area, but kills the shape
of the canopy.
You can preserve the shape of it, and edge-gluing will surely
be effective.

[wardebest]

Excellent advice everyone! I will probably cut this one off and print out another. This was my second try at a jet and the canopy really put me off my game.

Just so you know I am not a total loser, attached is a pic of my very first model.