Want to make a clear canopy, looking for lessons learned

[Occupant]

Basically trying to make something that looks like a jet fighter canopy. have tried 3D resin printing in clear resin, sand, clear paint with mixed results on clarity. I also used a headlight restoration kit to get a clearer results but afterwards have had issue with the print warping and yellowing . So now i'm thinking of either vacuum forming one and wondering how well it will bond to a base and hold up or the alternative would be to make a silicone mold and cast one in clear resin. Anyone have useful shortcuts or Do NOT do that to save me some tine and aggravation? Please and thank you...


before and after sanding, clear painting resin printed canopy eventually warped and de-bonded headlight kit yellowed a bit over time

[He Who Shall Not Be Named]

Basically trying to make something that looks like a jet fighter canopy. have tried 3D resin printing in clear resin, sand, clear paint with mixed results on clarity. I also used a headlight restoration kit to get a clearer results but afterwards have had issue with the print warping and yellowing . So now i'm thinking of either vacuum forming one and wondering how well it will bond to a base and hold up or the alternative would be to make a silicone mold and cast one in clear resin. Anyone have useful shortcuts or Do NOT do that to save me some tine and aggravation? Please and thank you...


before and after sanding, clear painting resin printed canopy eventually warped and de-bonded headlight kit yellowed a bit over time

Try this on for size:

[Occupant]

Thanks ! Now i have more questions... Using a polycarbonate what thickness do you recommend as there seem to be options? In some of the photos the vaccum formed pieces look frosted (before pic?)??? is that what you use the Meguires for or is that for polishing the plug - in my case will most likely use a 3D printed piece as the plug? What are you using to bond the vaccum formed pieces to the model, How robust is it? the examples shown seem to be static models - how well will this hold up in and under the water?

[jphatton]

[QUOTE=He Who Shall Not Be Named;n195695]



David,

Intrigued by your Space Shuttle like model. Is this a model for film / tv or one of the late 1960's / early 1970's Space Shuttle concept studies?

[MFR1964]

I used clear Vivak plate 1 mm for the spirou, heated it up inside a standard home oven at 200 degrees, when you see the Vivak droop inside it's frame for a good amount got it on the vacuummachine and drew the air out around the cockpit mold.
For now it's staying clear, you can glue that stuff with 2K epoxy.

Manfred.

[Occupant]

Looks like the shuttle from Buck Rogers TV show

[He Who Shall Not Be Named]

Looks like the shuttle from Buck Rogers TV show

Yup. A heavily re-worked plastic model kit of the American Shuttle. I goofed: failed to represent the faceted surfaces that housed the clear parts -- I made it as a compound curved 'cockpit canopy'. Wrong! At the time I only had some sketchy photos out of Starlog magazine to go on.

[He Who Shall Not Be Named]

Thanks ! Now i have more questions... Using a polycarbonate what thickness do you recommend as there seem to be options? In some of the photos the vaccum formed pieces look frosted (before pic?)??? is that what you use the Meguires for or is that for polishing the plug - in my case will most likely use a 3D printed piece as the plug? What are you using to bond the vaccum formed pieces to the model, How robust is it? the examples shown seem to be static models - how well will this hold up in and under the water?

.080" Butyrate or Polystyrene, clear.

The smoother the plug/puck/form/positive (whatever the hell they call that item these days!), the smoother the finish on the vacuformed item. Duh!

I'll use clear epoxy (vacuumed before application) or 'bezel glue'. Avoid butt joints they are week.

Strive to design the fit of the clear part into a groove or deep inlay into the non-transparent elements of the model for structural strength That way you can work the seam without getting into the eventual 'clear' elements of the canopy (seen to good effect on the FIREBALL Jr. model).

And vent the cockpit area to the dry section of the model submarine. A tight cockpit on a hot summer day will pop the clear part off the rest of the structure without a high-volume air reservoir behind it to mitigate the expanded air pressure.

[Occupant]

Thanks for the full response, couple more questions / comments. Butyrate or Polystyrene aren't something i see readily of Amazon, more of plastic supply houses. Any particular reason for using it over Polycarbonate?

Was thinking of trying Polyurethane Gorilla glue to secure, have had good luck with it in the past (pulled rubber off glue roller ??? so yeah it sticks well )

i was thinking of making mor of a edge vs shelf it sits on to bond to for a better bond line.

My cockpit is an access panel, have it vented with lots of holes and the canopy will have a bleed hole at the apex allowing it to flood and vent



FYI the cockpit attaches via 3 screws in keyways and is latched in place with a magnet on the canopy and in the body.

[He Who Shall Not Be Named]

I like this stuff:

Amazon.com: 20 Sheets 1.0MM Dental Hard Splint, Thermoforming Materials for Vacuum Forming Machine 5''x 5'' : Industrial & Scientific

Since there's no differential pressure between the cockpit and outside world, no sweat, go with the Gorilla goo.

[jphatton]

Yup. A heavily re-worked plastic model kit of the American Shuttle. I goofed: failed to represent the faceted surfaces that housed the clear parts -- I made it as a compound curved 'cockpit canopy'. Wrong! At the time I only had some sketchy photos out of Starlog magazine to go on.

Yes, now I recognise it as the Buck Rogers "Ranger 3" Shuttle. Interestingly a couple of the early design concepts for the Space Shuttle done by industry in the 1970/71 timeframe are similar to this model with large conformal fuel tanks (either internal or external) connecting to the engines