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DMC

Plunge Moulding Tutorial: Macchi M.39 float

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Over the past three years I have learned a few things about plunge moulding (no expert, however). As a way of paying back the pleasure I have derived from being a BM member I was wondering if a modest tutorial would go amiss.  It would take a little time but i’d be happy to do one. 

 

Cheers

 

Dennis 

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Ok, that’s three interested so we’ve got a cuorum.  I’ve been thinking about how to do it, photos etc, so will get on it ASAP.

 

Cheers

 

Dennis 

 

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Yes, step by step guidance please, and definitely with photo's... otherwise it didn't happen!  :closedeyes:

I've always wanted to be able to do this type of mould making but never known how; however, for those of us that don't comprehend so well nowadays, :clif: could you type slowly? 

 

Thanks.

 

Mike

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I will second Mikes interest Dennis...……….I look forward to your tutorial with  interest

 

Thanks

 

Raymond

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6 hours ago, bootneck said:

Yes, step by step guidance please, and definitely with photo's.

Yes indeed, plenty of photos.  Not much point without them.  Managed to get a start today.

 

4 hours ago, rayprit said:

I will second Mikes interest Dennis...……….I look forward to your tutorial with  interest

 

Thanks

 

Raymond

Thank you, Raymond

 

4 hours ago, bhouse said:

Me too please!

Pick a pew, have a seat

 

3 hours ago, cngaero said:

Count me in please. 

Done, thank you.

 

Would have replied sooner but our wi-fi (Virgin) has been dropping out every day since this "heat wave" began.  Annoying!

 

Cheers 

 

Dennis

 

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Hi Dennis, apologies for being late to the party, can i blag a seat near the front please, don't want to miss anything.

ATB

Jim

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Just got here, so I'll stand at the back. Definitely something I'd look at.

 

 

Chris

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28 minutes ago, dieselweasel said:

Hi Dennis, apologies for being late to the party, can i blag a seat near the front please, don't want to miss anything.

ATB

Jim

Not late, Jim, haven’t started yet.  Wi-fi our all day.  In fact everyday since this so-called heatwave began.  Should get something up this weekend.

 

Dennis

8 minutes ago, dogsbody said:

Just got here, so I'll stand at the back. Definitely something I'd look at.

 

 

Chris

Welcome, Chris, proper crowd now.

 

Dennis

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 Yesterday I spent a considerable amount of time on a back story of sorts and then lost it all when this iPad recycled.  I’ve tried copy and paste on my laptop but had no luck. So, II’m going to tray again, quickly, with the iPad and try to get some text in before it recycles again.

 

Starting right away with the photos:

The first one up is the book that started all this scratch building off.  I found my first copy in a second hand book shop.  Long out of print (‘75) it really opened my eyes as to what could be done with “plastic card”.  Mr Woodman was a genius with the stuff.  Copies are still available on the auction site. A couple at ridiculous prices.  Pity.

 

Next picture is of an Otaki FW190.  My first real attempt at modifying a model.  Using wooden moulds, I plunged a cowl, cowl ring and canopy.  Took a few tries but I eventually got something I could use.  Thank you Mr Woodman.

 

Next up is a four-part photo of the clay I use for the male moulds.  The beige is Super Sculpey, the grey is Super Sculpey Firm.  The firm is indeed firm so I mix it about 50/50 with the Firm to make it a little more pliable.  I run it through an old pasta machine several times and then roll it around until it’s well blended.  The photo bottom right is a mould for a Testors U-2 camera bay hatch.  I vacuum formed it but in hindsight I think I could have plunge moulded it.  Bottom left are moulds for the canopy of my P-38 build(s).  I don’t use toothpicks anymore and I’ll get around to the reason why later.

 

Fourth photos show what can be done if a mould is not quite the right shape.  I use Liquid  Sculpey to fix a thin piece of clay to the already baked mould and then bake it again.   The clay will stand several bakings so additional clay can be added a bit at a time if needed.  

 

Next photo: balsa wood for the female moulds.  The platform is about 1/4” and the riser about twice that.  If I run out of the 1/4” stuff I glue two thinner pieces together.  The riser has to be thick enough to keep the plunge from bottoming out.  I use bulldog clips to clamp the styrene to the female platform leaving just enough room for the side clips to clear. 

 

Next, before I epoxy the clay mould to the handle, I take it out on a scrap of plastic and then transfer the outline to the female mould platform and then cut it out.  I discovered that cutting out the shape for the male mould was easier if I split the platform down the middle and then cut the shape(s) out to the pencil lines.  Then I glued the two halves together and,  when set, finished up by shaving thin slivers out until the male mould is a tight fit with no more clearance than the thickness of the styrene then I intend to use.  This is important as to much clearance will produce a sloppy plunge.

 

The last two photos are of the little Revell Camel that I started as I enlisted in BM.  The cowling, the hump and the “canvas” wheel covers were plunge moulded.  I used a dowel for the cowling mould and a piece of clay for the hump.  I really enjoyed working on the little Camel until I accidentally snapped the lower wing off.  

 

So, got most of what I wanted to say before I lost it again.  More yet to come.

 

Please, any criticism,, suggestions or questions have it and thanks for looking.

 

Cheers 

 

Dennis

 

 

 

 

 

 

d960a87c-58b3-4af9-973e-87667b3e1cef.JPG

 

6673b545-ce92-468f-8820-6795e310af4f.png

 

844857ff-4b26-494a-8540-78e00fe517ce.JPG

 

413a0079-4684-4ad3-bba4-48591a267c77.JPG

 

d333f801-192c-44b3-ae16-f5b153712b14.JPG

 

47a5ce37-2d42-4bcb-9516-d31915622361.JPG

 

1e985c9f-e8d5-444e-8217-2267831506b5.JPG

 

b6751ffc-f2aa-45f8-9ab1-7620b62504a9.JPG

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This looks fascinating.

 

If I'm ever doing something like this I type the text in word (or similar program), you can also add the URLs then cut and paste to the site, that way I have an easy to use backup copy if summat goes wrong. In the early days I lost too many long (for me) posts because I'm a sh[t slow typist and I was taking too long to "submit".

 

You can also just copy and past it all back into Word or editing if you're not happy with it before submitting. 

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6 hours ago, Murdo said:

This looks fascinating.

 

If I'm ever doing something like this I type the text in word (or similar program), you can also add the URLs then cut and paste to the site, that way I have an easy to use backup copy if summat goes wrong. In the early days I lost too many long (for me) posts because I'm a sh[t slow typist and I was taking too long to "submit".

 

You can also just copy and past it all back into Word or editing if you're not happy with it before submitting. 

Thanks, Murdock, it is I think and not just because I’m doing it.  It’s the sort of thing I’d want to learn myself.

 

Sorry about the mixup.  My wife has also suggested I try something like cut and paste so I will sort something out today.

 

Dennis

3 hours ago, stevehnz said:

Excellent. I'll be in on this too please. :)

Steve.

Jump aboard, I’ll sort things out today.

 

Dennis

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Okay, managed to add some text to the photos.

 

Dennis

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Posted (edited)
On 7/7/2018 at 18:24, DMC said:

 

 

 

 Yesterday I spent a considerable amount of time on a back story of sorts and then lost it all when this iPad recycled.  I’ve tried copy and paste on my laptop but had no luck. So, II’m going to tray again, quickly, with the iPad and try to get some text in before it recycles again.

Using Chrome, if I 'lose' a post, when you click the reply button, the browser will restore previous content.#

what browser are you using?

I also juts edited the below to get the captions next to the relevant pics

 

Quote

 

The first one up is the book that started all this scratch building off.  I found my first copy in a second hand book shop.  Long out of print (‘75) it really opened my eyes as to what could be done with “plastic card”.  Mr Woodman was a genius with the stuff.  Copies are still available on the auction site. A couple at ridiculous prices.  Pity.

 

d960a87c-58b3-4af9-973e-87667b3e1cef.JPG

 

The  entire book is available here, with the permision of the late Mr Woodman I think (form searching this down)

 

http://web.archive.org/web/20080122044909/www.wwimodeler.com/harry/woodman.html

 

I have some old Scale Models magazines, from the early 1970's, and they have some of Mr Woodmans work, which is still well worth a read, one from 1976 is about making your own photoetch!

 

 

 

Next picture is of an Otaki FW190.  My first real attempt at modifying a model.  Using wooden moulds, I plunged a cowl, cowl ring and canopy.  Took a few tries but I eventually got something I could use.  Thank you Mr Woodman.

Quote

6673b545-ce92-468f-8820-6795e310af4f.png

 

Next up is a four-part photo of the clay I use for the male moulds.  The beige is Super Sculpey, the grey is Super Sculpey Firm.  The firm is indeed firm so I mix it about 50/50 with the Firm to make it a little more pliable.  I run it through an old pasta machine several times and then roll it around until it’s well blended.  The photo bottom right is a mould for a Testors U-2 camera bay hatch.  I vacuum formed it but in hindsight I think I could have plunge moulded it.  Bottom left are moulds for the canopy of my P-38 build(s).  I don’t use toothpicks anymore and I’ll get around to the reason why later.

 

 

Quote

844857ff-4b26-494a-8540-78e00fe517ce.JPG

Fourth photos show what can be done if a mould is not quite the right shape.  I use Liquid  Sculpey to fix a thin piece of clay to the already baked mould and then bake it again.   The clay will stand several bakings so additional clay can be added a bit at a time if needed.  

413a0079-4684-4ad3-bba4-48591a267c77.JPG

Next photo: balsa wood for the female moulds.  The platform is about 1/4” and the riser about twice that.  If I run out of the 1/4” stuff I glue two thinner pieces together.  The riser has to be thick enough to keep the plunge from bottoming out.  I use bulldog clips to clamp the styrene to the female platform leaving just enough room for the side clips to clear. 

Quote

d333f801-192c-44b3-ae16-f5b153712b14.JPG

Next, before I epoxy the clay mould to the handle, I take it out on a scrap of plastic and then transfer the outline to the female mould platform and then cut it out.  I discovered that cutting out the shape for the male mould was easier if I split the platform down the middle and then cut the shape(s) out to the pencil lines.  Then I glued the two halves together and,  when set, finished up by shaving thin slivers out until the male mould is a tight fit with no more clearance than the thickness of the styrene then I intend to use.  This is important as to much clearance will produce a sloppy plunge.

Quote

47a5ce37-2d42-4bcb-9516-d31915622361.JPG

The last two photos are of the little Revell Camel that I started as I enlisted in BM.  The cowling, the hump and the “canvas” wheel covers were plunge moulded.  I used a dowel for the cowling mould and a piece of clay for the hump.  I really enjoyed working on the little Camel until I accidentally snapped the lower wing off.  

Quote

1e985c9f-e8d5-444e-8217-2267831506b5.JPG

 

b6751ffc-f2aa-45f8-9ab1-7620b62504a9.JPG

 

 

there are various tutorials up on youtube

for example

 

 

 

this is a technique I'd run across before,  and a maybe not much use for a small scale part, but could have some applications

 

 

 

Edited by Troy Smith

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Yeees, that’s much better, Troy.  Thanks for doing that.  I have two devices that I use to get text and photos on BM., an iPad and a Lenovo laptop.  My camera is an oldish Samsung NV7 that I use because it has that 2,3 or 4 in one photo feature.  I upload my photos on Village Photos, which is ok now that I have learned to use them. One thing, that you hit on right away was having to bunch all the text at the begging rather that in between each photo, which is how I did it when I used PhotoBucket (expletive deleted).  I tried to separate the photos with text when I first started with VP but had no luck with it so I just gave up on it and did it like I did it above.  

 

Anyway, as I admitted to over on Chat, I am the consummate Luddite and struggle sometimes with things of a technical nature.

Hell, when I was a tyke the telegraph was high tech (joking of course).  I have an old Blackberry phone with the keypad which I will not relinquish for any of the newer smartphones that everyone seems to have these days. 

 

Sorry, I digress.  Thanks again for rearranging everything.  Looks and reads much better.  I’ll have another look at VP the next time  I post more that one image to post.  Perhaps I overlooked something.

 

Cheers

 

Dennis

 

 

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Posted (edited)

Dennis

YEARS ago I formed a turret from a length of wood to plunge and I thought it VERY basic but it worked.

 

I wonder now if I could fill a canopy with AIR dried clay, let it set and use that to plunge ??

 

I am asking as I would like to know more about plunge forming rather than think about  a vacuum forming machine

 

Your thoughts and suggestions would be appreciated

 

Ian

Edited by Mancunian airman

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Hi Ian

 

I have done something similar with polymer (bake to harden) clay.  It was a kit canopy and I filled it wth clay and carefully removed it (it took a few tries) and baked it.   I then covered it with a thin layer of clay to enlarge it slightly and baked it again.

This was just an experiment, however.

 

So, yes, you could try it but as I have never used air dried clay I wonder if it would be difficult to remove from the canopy without destroying it.  Is it a bubble canopy?  Bulged at the top?  You might have a problem getting the bubble shape by plunge moulding if the base as much narrower than the top.  

 

Hope this at least partly answers your question.  I plan on on dealing with this very problem in a future post.

 

Cheers

 

Dennis

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8 hours ago, dogsbody said:

A copy of Woodman's Scale Model Aircraft is available in PDF format here: https://www.scribd.com/document/180597548/Scale-Model-Aircraft-in-Plastic-Card-pdf

 

 

Chris

Thanks for that.  Troy also provided a link for access to the book. Worth a look.

 

Dennis

 

 

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Posted (edited)

Why clay?  I like using it simply because I like sculpting with it.   Also because I find it very versatile.  Make a mistake and it's easy to add a bit and re-bake it.  Polymer clay can stand several bakes without burning or crumbling.   The small bust of Pallas Athena was done in several stages.  

 

But wood, or some other material, can also be used.  The curved mould in the second photo was easier to carve from balsa then sculpt from clay.

 

I used it to plunge the concave section that the flaps mate up with on the Corsair wing. 

 

Some moulds would be difficult, for me anyway, to carve from wood.  The mould for the Corsair wing intake is an example.  Plunging the intake was a two step process.  After the first plunge,  I had to flip it over while still hot and plunge the rolled in intake. I admit it took me several tries before I got something usable.

 

Second photo: 

 

Canopies and windscreens are probably the most often plunge moulded replacement, or new, parts of a model kit.  Canopies that are too thick, lost or damaged can be replaced by plunge moulding a new one.  Canopy moulds can certainly be carved from wood but I think there might be some issue with the wood grain showing on the clear PETG.

 

Because I altered the fuselage of the Monogram Corsair I'm building, the kit canopy couldn't be used.  An aftermarket replacement would have saved a lot of time, and would have been the chosen way to go for most modellers, but I had to sculpt and plunge a replacement.  

 

Using the kit canopy, with a little petroleum jelly as a release agent (necessary), I pressed a thin layer in first to get a good fit and then added a, shaped, larger piece.

 

I got something like this after baking: third photo

 

I then enlarged those two pieces with more clay, baked them and shaped them using the fuselage as a guide.  I've made the female moulds to fit and later today I'll plunge the moulds in white styrene to see how close I was to getting a good fit. (Might have to edit this also as I can barely read the print using my laptop)

 

Cheers and thanks for looking.

 

Dennis

 

b0e53fe9-77fa-4391-b0db-219ffb262c6d.JPG

 

1b4ca993-fc4b-4d80-be46-bf0777ba911e.JPG

Edited by DMC

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Okay, not bad for the first plunge but I'm going to reshape the moulds a little and try another set.  These were done using .030 white styrene.  Using white initially gives me some idea of any changes I need to make.  In Detail & Scale I learned that the canopy actually raises up a couple of inches as it slides back.  Good book that!

 

Thanks for looking

 

Dennis

 

 

798238ce-3171-4a15-a4bd-3848e702abbd.JPG

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Text in a few minutes.

First photo is of the old toaster oven I use.  I’ve marked the dials with two settings, one for baking the clay and the other for heating the styrene for plunging.  I used the meat thermometer at first when I had the oven in the garage and it got quite cold out there.  The styrene takes anywhere from 12 to 15 minuets to heat up depending on the thickness.   Not sure what material the white pad is but I use it to keep the balsa, or clay, from coming in contact with the tile.  Doesn’t melt or burn.

 

Second photo top left: in, top right:  not ready although the styrene has started to sink into the opening, 

bottom left:  better, styrene should be very wet looking with a slight yellow tinge,  bottom right:  plunge

 

Let it cool a bit then remove clips and separate from the mould.  Looks ok but, as you can tell by the crease on one side, the mould wasn’t equal distance around the opening.  Try again.

 

Thanks for looking

 

Dennis

 

Apologies for the poor quality of the photos but it was a bit tricky trying to do this in front of the hot oven.

 

 

c929d0df-d23b-44cb-beca-7712a5404c01.JPG

 

1e6c04b0-e147-46b8-8f39-63aa675b9463.JPG

 

d303d69e-5995-4173-b31e-cffe5f89e630.JPG

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