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- #61
Airframes
Benevolens Magister
Will do Andy.
1/32nd scale Mosquito FBVI conversion.
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- #62
Airframes
Benevolens Magister
I've now done a trial first moulding of the canopy which, although reasonable, could be better, as the moulded item shows minor signs of imperfection, indicating that the male mould could use another coat of clear varnish and more polishing.
However, for the purposes of test fitting, and to illustrate the process involved in moulding by this method, it will suffice for now.
After carving the male mould, and cutting the female from balsa sheet or other suitably stiff material, it is essential to obtain a glass-smooth finish on the male mould pattern, as any and all imperfections, in the way of grain, lumps and bumps or depressions will be transferred to the moulded part. This is not as noticeable on 'solid' plastic parts, but shows up easily on clear sheet.
PIC 1 shows the male mould sealed with a mix of clear gloss enamel varnish and talcum powder. When fully set, this is repeated as required, and then followed by two or three coats of clear gloss. (NOTE acrylic varnish is not suitable for this process.) This is then very lightly rubbed down and polished until smooth as glass.
PIC 2. A piece of clear plastic sheet, in this case approximately 1mm thick, is securely taped to the female mould, allowing a generous surround, to cope with stretch.
The female mould is then held under the kitchen grill, clear sheet upwards, at least four inches (100mm) away from the heat source (more if a gas grill) and gently moved around in a circular motion, until the clear sheets starts to become only just floppy. Any longer and it will rapidly sag and develop holes !
PIC 3. Moving quickly, the female mould is removed from the heat source and, in one swift movement, the male mould is plunged through from the same side as the clear sheet and held until cool. this takes only a few seconds.
PIC 4. For the purposes of this demonstration, a pic was taken showing the male mould in place within the clear moulded part. This may have contributed to the slight imperfections mentioned earlier, as it is a good idea to remove the male pattern as soon as possible, to minimise any possibility of the varnish, now quite warm, leaving marks on the clear sheet.
PIC 5. The clear part is now moulded.
PIC 6. The tape is removed from the clear sheet, and the part removed from the female mould. This can now be trimmed from the sheet, and the male can be re-inserted to act as a cutting guide if required.
Once I've trimmed the part, it can be checked for fit against the cockpit opening. If all is well, then i may still use this canopy, or possibly apply another clear coat to the male mould, re-polish and mould another part.
I hope this proves useful, and thanks again for the continued interest.
However, for the purposes of test fitting, and to illustrate the process involved in moulding by this method, it will suffice for now.
After carving the male mould, and cutting the female from balsa sheet or other suitably stiff material, it is essential to obtain a glass-smooth finish on the male mould pattern, as any and all imperfections, in the way of grain, lumps and bumps or depressions will be transferred to the moulded part. This is not as noticeable on 'solid' plastic parts, but shows up easily on clear sheet.
PIC 1 shows the male mould sealed with a mix of clear gloss enamel varnish and talcum powder. When fully set, this is repeated as required, and then followed by two or three coats of clear gloss. (NOTE acrylic varnish is not suitable for this process.) This is then very lightly rubbed down and polished until smooth as glass.
PIC 2. A piece of clear plastic sheet, in this case approximately 1mm thick, is securely taped to the female mould, allowing a generous surround, to cope with stretch.
The female mould is then held under the kitchen grill, clear sheet upwards, at least four inches (100mm) away from the heat source (more if a gas grill) and gently moved around in a circular motion, until the clear sheets starts to become only just floppy. Any longer and it will rapidly sag and develop holes !
PIC 3. Moving quickly, the female mould is removed from the heat source and, in one swift movement, the male mould is plunged through from the same side as the clear sheet and held until cool. this takes only a few seconds.
PIC 4. For the purposes of this demonstration, a pic was taken showing the male mould in place within the clear moulded part. This may have contributed to the slight imperfections mentioned earlier, as it is a good idea to remove the male pattern as soon as possible, to minimise any possibility of the varnish, now quite warm, leaving marks on the clear sheet.
PIC 5. The clear part is now moulded.
PIC 6. The tape is removed from the clear sheet, and the part removed from the female mould. This can now be trimmed from the sheet, and the male can be re-inserted to act as a cutting guide if required.
Once I've trimmed the part, it can be checked for fit against the cockpit opening. If all is well, then i may still use this canopy, or possibly apply another clear coat to the male mould, re-polish and mould another part.
I hope this proves useful, and thanks again for the continued interest.
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Coors9
Senior Airman
Cool ...
T Bolt
Colonel
Very nice "How-To" Presentation Terry. Very useful information.
very clever Terry
yeah, cool from here too!
hawkeye2an
Staff Sergeant
Nicely done. What material are you using and what thickness?
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- #68
Airframes
Benevolens Magister
Thanks guys. The material is standard clear plastic sheet, from the local Model Shop. Thickness is actually approximately 0.5mm, not 1mm as stated, in this instance.
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Looking good Terry!
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- #70
Airframes
Benevolens Magister
Thanks Hugh.
The first trial moulding has shown that perhaps a little filing and sanding may be required around the cockpit opening. This will be done, checking fit of the canopy as it proceeds. Fitting the actual clear moulded part will be slightly tricky, and may entail some 'botching' here and there, but any rough joints can be corrected at the painting stage, much later.
The first trial moulding has shown that perhaps a little filing and sanding may be required around the cockpit opening. This will be done, checking fit of the canopy as it proceeds. Fitting the actual clear moulded part will be slightly tricky, and may entail some 'botching' here and there, but any rough joints can be corrected at the painting stage, much later.
Crimea_River
Marshal
Excellent demo Terry. Thanks a bunch.
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- #72
Airframes
Benevolens Magister
You're welcome Andy.
tigerdriver
Staff Sergeant
Top Banana as every Terry
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- #74
Airframes
Benevolens Magister
Cheers mate. I've started the preparation work on the cockpit, but haven't got far yet, as life has been getting in the way this last week !
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- #75
Airframes
Benevolens Magister
With most of the preparation work completed, I'm now almost ready to start scratch-building the main cockpit components.
PIC 1. Shows the three parts of the damaged starboard fuselage section repaired, and the joints sanded.
PIC 2. To reinforce the joints, particularly for future work and handling, strips of plastic card were cemented across the areas on the inside of the fuselage. The nose windows were also blanked-off at this time.
PIC 3. Nose windows blanked with plastic card, to be filled later, when the fighter nose is made.
PIC 4. There are small depressions following the outline of the forward section of the wing roots on both sides. These needed to be covered to facilitate detailing later, and avoid an unsightly, shallow area. Note also the very basic detail moulded on the cockpit sides, which will be covered by scratch-built parts.
PIC 5. Pieces of plastic card were cut to shape and glued into the depressions, and the joints will be filled once set.
PIC 6. The kit showed two moulded circles representing the identification lamps. There should be three of these, so the moulded items were drilled out, with a third hole being drilled aft, and then blanked-off internally with plastic card. These will be painted and glazed during the final stages of the build. Forward of these, the engraving representing the bomber/PR camera port was sanded off, as this aircraft did not have an open, glazed port.
Thanks for your kind comments and continued interest in this project, and I hope to post another up-date fairly soon.
PIC 1. Shows the three parts of the damaged starboard fuselage section repaired, and the joints sanded.
PIC 2. To reinforce the joints, particularly for future work and handling, strips of plastic card were cemented across the areas on the inside of the fuselage. The nose windows were also blanked-off at this time.
PIC 3. Nose windows blanked with plastic card, to be filled later, when the fighter nose is made.
PIC 4. There are small depressions following the outline of the forward section of the wing roots on both sides. These needed to be covered to facilitate detailing later, and avoid an unsightly, shallow area. Note also the very basic detail moulded on the cockpit sides, which will be covered by scratch-built parts.
PIC 5. Pieces of plastic card were cut to shape and glued into the depressions, and the joints will be filled once set.
PIC 6. The kit showed two moulded circles representing the identification lamps. There should be three of these, so the moulded items were drilled out, with a third hole being drilled aft, and then blanked-off internally with plastic card. These will be painted and glazed during the final stages of the build. Forward of these, the engraving representing the bomber/PR camera port was sanded off, as this aircraft did not have an open, glazed port.
Thanks for your kind comments and continued interest in this project, and I hope to post another up-date fairly soon.
Attachments
Lucky13
Forum Mascot
Looking dogs sphericals old boy, top drawer and all that rot......carry on!!
Damn good recovery Terry....!
let the work begin, looks good so far Terry
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- #80
Airframes
Benevolens Magister
Thanks very much guys. With a bit of luck, I might get started on the cockpit scratch-building tonight.
