Let us turn our attention to the canopy. You will have noticed that it has yellowed and I doubt it's going to get any better. So starts an adventure in canopy moulding!
For my birthday I asked for one of those (cheapish) dental vacuform machines that can be sourced from various suppliers but are all the same machine. I've wanted one for a while but starting this kit gave me an immediate reason to acquire one. So the first thing I did was to make a plaster of Paris mould of the kit part. This was a quick proof of concept I didn't take a lot of care over it and just used some clear packaging PET that I had to hand. Anyway, the results were surprising with very good duplication of the original parts detail - though not that great in itself.
I also decided to have a go with the thermo moulding plastic and some UV resin that was meant to be hard(er) than the resin glue. This worked in as much as I got a good copy, but the surface was not clear and the resin was not hard enough to be sanded/polished smooth. A two-part hard resin may have produced something that could be cleaned up but not worth the effort from this kind of mould.
I cut out the test vacform part to see how well it fitted, it was a bit meh and it was at this point I decided to redo the canopy from scratch. I taped the fuselage halves but CA'd the cockpit opening together. This was squared and levelled off. I used some plastic strip to move the step between the canopy and windscreen further forward - and help to tie the halves together. The area had a layer of clear tape applied to help the mould to separate later. From some masking tape templates, 10thou plastic card was applied with CA. This defined the rear and bottom edges. Using the plans formers were cut and added to define the canopy and windscreen framing. An additional piece gave the canopy profile.
Milliput was used to overfill gaps between the formers. Once dry I could prise it off the fuselage and remove the tape.
And then sanded back to the formers until they were just exposed. Tricky to make sure I didn't create any concave surfaces or undercuts.
Though Tamiya tape might have sufficed I didn't think it would create sharp enough framing. Vinyl tape is too thick and stretchy. I decided to try some Aluminium tape at least I was sure it would have other uses. This worked excellently and I managed to do all the framing at my first attempt. The tape can be burnished with a cocktail stick and you can remove wrinkles when you bend it around compound curves. The canopy and windscreen frames were done separately with the vague hope that the seam between them may be picked up.
The master needed to be mounted using some plasticine, this was by far the most fiddly task. A quick mould box from foam board and hot glue. I was worried the plaster of Paris might pull off the Al tape when demoulding so after reading around used some petroleum jelly thinned with white spirit as a mould release. This may have worked very well or been unnecessary as the master fell out when I came to remove it. I thought my vortex paint mixer would be a good tool for removing bubble but I still had a couple that I filled with putty after the plaster dried
The mould was far too deep so I used a surform to remove the excess plaster. Air holes were drilled at the extremes, use an unpopular drill size as this is a great way to blunt twist bits. I tried out the ball bearing that came with the vacform machine to lessen the depth of the draft around the mould. Following some advice from TeeELL I bought some 0.5mm PETG clear plastic sheet for better results. This softens quicker and doesn't smell like PET does.
In seconds I had an excellent pull. Would you believe it even the seam detail between the framing was clearly evident! However, I noticed it wasn't as clear as early tests and there was a streaky finish - good grief I think the brush strokes of the mould release had been captured! Looks like I will need to create another plaster mould for the final part but this has been a very enjoyable learning experience so far and opens up a lot of opportunities for future builds.
