**** DONE: 1/48 Blackburn Roc – Sqn Ldr Clark RAF. BofB Group Build.
- Thread starter Vic Balshaw
- Start date
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- #42
Vic Balshaw
Major General
It's been a pig of a day. Apart from the index finger throbbing from closing the door on it, I managed to snap the canopy in half yesterday so I glued it together allowing it to set overnight in the hope that I will be able to rub the glue off with increasing grades of emery. Sadly when picking it up tonight, it again snapped in half, so if any of you guys have got any ideas................please HELP me.
Earlier on in the day I also discovered that a vital part of the cockpit instrument panel had gone missing and spent over 45 minutes hunting for it, eventually I found it stuck to the back of the building instruction sheets. It was the little bit on the left of the picture.
The next thing to be lost was part of the belt straps for the gunners seat. It just pinged away into oblivion when I lifted the whole belt to fit to the seat. A hunt for it came to nothing so I improvised and made a new set and not long after sticking the new bits together, painting them and setting them aside, the pinged away bit glistened in the evening setting sun............
To cap all this off, while test fitting the cockpit floor, Mr Clumsy ....
.....snapped off the top half of the control column, so that was a double pin drill job and a pin inserted to help reset the part. Anyway, despite all that, progress is being made as seen below
Earlier on in the day I also discovered that a vital part of the cockpit instrument panel had gone missing and spent over 45 minutes hunting for it, eventually I found it stuck to the back of the building instruction sheets. It was the little bit on the left of the picture.
The next thing to be lost was part of the belt straps for the gunners seat. It just pinged away into oblivion when I lifted the whole belt to fit to the seat. A hunt for it came to nothing so I improvised and made a new set and not long after sticking the new bits together, painting them and setting them aside, the pinged away bit glistened in the evening setting sun............
To cap all this off, while test fitting the cockpit floor, Mr Clumsy ....
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Airframes
Benevolens Magister
Ever thought of starting a new career in demolition Vic?!!!
Great work so far mate. That canopy is crying out to be moulded from clear sheet - easy peezy with that shape too.
Great work so far mate. That canopy is crying out to be moulded from clear sheet - easy peezy with that shape too.
T Bolt
Colonel
Nice progress Vic. I'd do what Terry said and use some clear plastic sheet for the canopy, it will be clearer than the original.
When I was building the Goblin for the last GB the panel went missing also. Spent quire a lot of time looking for it before I found it stuck to the bottom side of my fore arm
When I was building the Goblin for the last GB the panel went missing also. Spent quire a lot of time looking for it before I found it stuck to the bottom side of my fore arm
- Thread starter
- #45
Vic Balshaw
Major General
I've had that same thought myself, re moulding a new canopy and though I've seen how on a recent thread, can't quite remember how to form the shape. I know it is with heat over a mould, but was it with a warm hair drier or some other means...............
Doing ok there Vic, despite your best efforts to sabotage your own work.....
looks great so far Vic
Crimea_River
Marshal
Vic, your tale reminded me of Python's Mr. Gumby skits.
As for the molding bit, a few days back I had responded to Jason (Jayl) who did the same to his Spit I build. I suggested just using the broken piece as a mold, then heating the card over it with a hair dryer.
As for the molding bit, a few days back I had responded to Jason (Jayl) who did the same to his Spit I build. I suggested just using the broken piece as a mold, then heating the card over it with a hair dryer.
Airframes
Benevolens Magister
Try to avoid using an injection moulded canopy as a master for heat moulding!
The clear sheet needs to be heated until it starts to become 'floppy', and this = hot! The heat can deform the kit part very easily, especially as it (the male master) should be pushed through the clear sheet whilst the latter is fixed over a holder into which is cut the female mould former. (Injected clear parts are not as resilient or heat resistant as injected 'solid' plastic parts.)
It's sometimes possible to get away with it, if the kit part is filled with a suitable stiffener, such as Milliput, and an acceptable result is obtained first go, second attempt at a push. After this, the kit canopy will begin to deform, and/ or bubble.
BUT! The finished part will then be over-sized, as the male mould pattern needs to be smaller all round, to allow for the thickness of, and the stretching, of the clear plastic used !
The simplest way is to carve a master from balsa, seal it with a mix of talcum powder and clear gloss varnish (enamel or polyurethane, not acrylic), then sand this gently until smooth. This fills the wood grain. Then, apply another two or three coats of the same clear gloss, allowing to dry thoroughly between coats, and polish when hardened.
It's imperative to obtain an even, glass-like surface on the master, as even the tiniest imperfection will transfer to the moulded part. With this in mind, framework can be moulded in, by building the shapes of the frame with the relevant sized strips of thin masking tape, such as Tamiya tape, adding these after the talc/varnish/polish stage, but before the clear gloss varnish stage.
Hope this helps.
The clear sheet needs to be heated until it starts to become 'floppy', and this = hot! The heat can deform the kit part very easily, especially as it (the male master) should be pushed through the clear sheet whilst the latter is fixed over a holder into which is cut the female mould former. (Injected clear parts are not as resilient or heat resistant as injected 'solid' plastic parts.)
It's sometimes possible to get away with it, if the kit part is filled with a suitable stiffener, such as Milliput, and an acceptable result is obtained first go, second attempt at a push. After this, the kit canopy will begin to deform, and/ or bubble.
BUT! The finished part will then be over-sized, as the male mould pattern needs to be smaller all round, to allow for the thickness of, and the stretching, of the clear plastic used !
The simplest way is to carve a master from balsa, seal it with a mix of talcum powder and clear gloss varnish (enamel or polyurethane, not acrylic), then sand this gently until smooth. This fills the wood grain. Then, apply another two or three coats of the same clear gloss, allowing to dry thoroughly between coats, and polish when hardened.
It's imperative to obtain an even, glass-like surface on the master, as even the tiniest imperfection will transfer to the moulded part. With this in mind, framework can be moulded in, by building the shapes of the frame with the relevant sized strips of thin masking tape, such as Tamiya tape, adding these after the talc/varnish/polish stage, but before the clear gloss varnish stage.
Hope this helps.
vikingBerserker
Lieutenant General
Ouch! But the work is looking nice!
- Thread starter
- #51
Vic Balshaw
Major General
Thanks Gents had a much better day today though it did start with me dropping the pot lid off the tea caddy.................thank god for super glue.
Thank you also Terry for the explanation, I've started on the balsa mould and maybe tomorrow will be able to seal a couple of times, smoothing down between applications. When you say clear plastic sheet, would the clear plastic used on a folder/file that you can get from a stationers be the same thing, it's kind of very thin but very similar to a vacform canopy.
Did do a bit more work, fitting up the cockpit into one half of the fuselage, had to then fit a fire line from the extinguisher at the back of the fuel tanks to the engine and put in a voice pipe..............fiddly stuff. Hop to have pics tomorrow.
Thank you also Terry for the explanation, I've started on the balsa mould and maybe tomorrow will be able to seal a couple of times, smoothing down between applications. When you say clear plastic sheet, would the clear plastic used on a folder/file that you can get from a stationers be the same thing, it's kind of very thin but very similar to a vacform canopy.
Did do a bit more work, fitting up the cockpit into one half of the fuselage, had to then fit a fire line from the extinguisher at the back of the fuel tanks to the engine and put in a voice pipe..............fiddly stuff. Hop to have pics tomorrow.
Sounds like a better progress day Vic! look forward to them pics mate!
Airframes
Benevolens Magister
Only some small demolition jobs today then Vic?!!
That plastic might work, but it might be a bit thin, which can cause uneven and unmanageable edges, as well as possible thin spots, bubbles or holes. This is because the clear plastic looses dimensional stability when heated, and of course goes thin as it stretches over the former. I'd suggest you try it on a rough balsa mould first, unless you can get some clear sheet from a model shop. Most good shops sell it, in 8 x 10 inch or slightly larger, in various thicknesses. For this job, anything between 0.5mm and 1 mm thick (approximately) will be fine. Once moulded, the 0.5mm will be down to around 0.25 to 0.025 mm thick, and the 1mm around 0.5 or maybe a bit less.
As a rough guide, cut a piece which is approximately 4 to 6 times the size of the balsa male mould in length and width in plan view, and attach this firmly to the female mould, with the moulding aperture centralised.
If you have a kitchen stove with gas hobs, these are ideal to heat the sheet, as there is more control, and the effects are immediately visible, compared to electric or infra red hobs, or an electric grill.
The clear sheet can be fixed to the female mould sheet (this something like 1/4 inch balsa sheet, or equivalent hard, stiff card.) with ordinary masking tape or 'Sellotape', but ensure this is well stuck down, with the ends wrapped around the clear sheet and the mould, and on the opposite side to the heat source. (this to prevent the heat from lifting the tape ends.)
Hold this combination over the flame/heat source, with the clear sheet uppermost, at a height of no less than around five or six inches (wear gloves or use tongs!), and gently move it around in a circular motion to prevent fogging or melting. When the clear sheet starts to go 'floppy' and wants to curl up and pull away the tape, immediately plunge the male mould through the sheet in one smooth, swift, but gentle motion, until the base of the male mould is level with the top surface of the female mould, or at least inside the thickness of the female mould.
Allow to cool for a few seconds, then remove the male mould. Allow a few more seconds to cool, then remove the now baked-on tape, and take the moulded sheet off the female mould, carefully lifting the moulded shape through the aperture.
The male mould can be placed into the moulded shape to act as a cutting guide, and the part removed by cutting with a new blade in the scalpel. The best way is to continuously, but gently and carefully score the cut lines, to avoid splits or slipping of the blade.
The part can be fixed to the model with poly cement or PVA.
Although it can happen, don't expect a perfect result first time, even with experience of doing this, as the control parameters are ... er... there aren't any !
Forgot to add - it's best to make the male mould deeper than the required shape of the part, to allow room for pushing through the female mould, and for ease of cutting. With a part for say, a Hurricane canopy, the male mould would have the required sloping sides, but from the base (of the canopy shape) to the bottom of the male mould would be vertical all round.
That plastic might work, but it might be a bit thin, which can cause uneven and unmanageable edges, as well as possible thin spots, bubbles or holes. This is because the clear plastic looses dimensional stability when heated, and of course goes thin as it stretches over the former. I'd suggest you try it on a rough balsa mould first, unless you can get some clear sheet from a model shop. Most good shops sell it, in 8 x 10 inch or slightly larger, in various thicknesses. For this job, anything between 0.5mm and 1 mm thick (approximately) will be fine. Once moulded, the 0.5mm will be down to around 0.25 to 0.025 mm thick, and the 1mm around 0.5 or maybe a bit less.
As a rough guide, cut a piece which is approximately 4 to 6 times the size of the balsa male mould in length and width in plan view, and attach this firmly to the female mould, with the moulding aperture centralised.
If you have a kitchen stove with gas hobs, these are ideal to heat the sheet, as there is more control, and the effects are immediately visible, compared to electric or infra red hobs, or an electric grill.
The clear sheet can be fixed to the female mould sheet (this something like 1/4 inch balsa sheet, or equivalent hard, stiff card.) with ordinary masking tape or 'Sellotape', but ensure this is well stuck down, with the ends wrapped around the clear sheet and the mould, and on the opposite side to the heat source. (this to prevent the heat from lifting the tape ends.)
Hold this combination over the flame/heat source, with the clear sheet uppermost, at a height of no less than around five or six inches (wear gloves or use tongs!), and gently move it around in a circular motion to prevent fogging or melting. When the clear sheet starts to go 'floppy' and wants to curl up and pull away the tape, immediately plunge the male mould through the sheet in one smooth, swift, but gentle motion, until the base of the male mould is level with the top surface of the female mould, or at least inside the thickness of the female mould.
Allow to cool for a few seconds, then remove the male mould. Allow a few more seconds to cool, then remove the now baked-on tape, and take the moulded sheet off the female mould, carefully lifting the moulded shape through the aperture.
The male mould can be placed into the moulded shape to act as a cutting guide, and the part removed by cutting with a new blade in the scalpel. The best way is to continuously, but gently and carefully score the cut lines, to avoid splits or slipping of the blade.
The part can be fixed to the model with poly cement or PVA.
Although it can happen, don't expect a perfect result first time, even with experience of doing this, as the control parameters are ... er... there aren't any !
Forgot to add - it's best to make the male mould deeper than the required shape of the part, to allow room for pushing through the female mould, and for ease of cutting. With a part for say, a Hurricane canopy, the male mould would have the required sloping sides, but from the base (of the canopy shape) to the bottom of the male mould would be vertical all round.
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- Thread starter
- #54
Vic Balshaw
Major General
Well as promised folks here are pictures of the latest developments, though the beast is now together and all clipped and braced up while glue sets.
Thanks also again Terry for the instructions, having read them several times, I've chickened out and hunting high and low for a replacement canopy, something will come up, it always does.
In the pics, the brown tube on the stbd side is the voice pipe twixt the gunner and the pilot, one has to remember that this rotating turret gun was the only armament the aircraft had and even then it would not traverse below the horizontal, no wonder they were soon converted to target towing. The blue pipe is the engine fire extinguisher which I'm proud to say is all my own work..............applause please...
............thankyou, thankyou, thankyou (as I take the bow). Needless to say the extinguisher is that red blob between the fuel tanks. OK, enough of the chat, here's the pics.
Thanks also again Terry for the instructions, having read them several times, I've chickened out and hunting high and low for a replacement canopy, something will come up, it always does.
In the pics, the brown tube on the stbd side is the voice pipe twixt the gunner and the pilot, one has to remember that this rotating turret gun was the only armament the aircraft had and even then it would not traverse below the horizontal, no wonder they were soon converted to target towing. The blue pipe is the engine fire extinguisher which I'm proud to say is all my own work..............applause please...
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Wildcat
Major
Looking good Vic!
Good stuff Vic....give yourself a pat on the back!
looks awsome Vic
Crimea_River
Marshal
Are you still bowing. You should be `cause I`m still clapping! Nicely done Vic.
Airframes
Benevolens Magister
Excellent work Vic!
Still using a Gosport tube eh? I suppose, being Navy, the gunner whistled down the tube, and gave instructions such as "Full Ahead" and "Ten degrees right rudder" !!!
Still using a Gosport tube eh? I suppose, being Navy, the gunner whistled down the tube, and gave instructions such as "Full Ahead" and "Ten degrees right rudder" !!!
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