Mosquito Mold Question

[PbyCat-Guy]

Since I've started A&P school, I've been wanting to know. What is the difference in molds used to produce static vs flying Mosquitos? To me a mold is a mold, but is there something that is different for the fuselage molds for an airworthy mosquito? Just curious. My dad and I always discussed building a replica mossie if we won the lottery and could afford such a project.

[JDK]

I'm not sure I understand the question - AFAIK, no-one has ever made a mould to just build static Mosquitoes. The first fuselage off the Glyn Powell mould in NZ was sold to Canada for a static rebuild, but the second aircraft off the mould is an airworthy rebuild.

[RMAllnutt]

JDK's right... the first shell off was just to prove that the mold dimensions were accurate. They used non-airworthy grade material, which is why the parts were sent for use in a static, as opposed to an airworthy, project.

Cheers,
Richard

[Bruce]

Glynns moulds, as the original prototypes were, are made of wood.

The production moulds were made of concrete.

Remember, there is an awful lot of metal in the Mossie; a lot more than people realise!


Bruce

[JDK]

The durability of a wooden mould would be enough for the few Glynn's planning, I'd assume?

Remember, there is an awful lot of metal in the Mossie; a lot more than people realise!

And the wing wasn't moulded, 'only' the fuselage.

[Rajay]

Okay, the links...

http://www.nzfpm.co.nz/article.asp?id=mosquito

http://www.mosquitorestoration.com/feedback.shtml

Thanks for posting these. Made for some very interesting reading. And the Gallery...Glynn's craftsmanship is to die for! The wood is so beautiful, it seems a shame to cover it with fabric and paint it.

The shots which showed the interior of the cockpit section painted with a green zinc chromate struck me as ironic. On the original aircraft, with no aluminum to corrode, they must have just been trying to make the military crews feel at home.

The photos of the various parts, bulkheads, ribs, etc. being assembled should themselves be hanging in an art gallery.

Anyone have an idea of what Gerry Yagen is paying for a brand new Mosquito? I have a feeling that even if Glynn is eventually able to build a 100 of them, they will ALL still be priceless!

[Matt Gunsch]

Glynns moulds, as the original prototypes were, are made of wood.

The production moulds were made of concrete.

Remember, there is an awful lot of metal in the Mossie; a lot more than people realise!


Bruce

Only the Canadians used concrete molds, they tried the wood ones like the brits, but decieded that concrete was better.

[John Dupre]

I assume that the Mosquito fuselage plywood was produced in sections and joined in the mold. were the joints of the fuselage shells designed to match up with internal stucture, i.e. bulkheads and formers? I remember reading that when the NASM was restoring its Albatross D.Va they were surprised to find the joints in the fuselage shells did not always line up with internal structure! NASM was replacing the shell piece by piece and had to make temporary formers in order to provide backing for the various glue joints.

[gregv]

I assume that the Mosquito fuselage plywood was produced in sections and joined in the mold. were the joints of the fuselage shells designed to match up with internal stucture, i.e. bulkheads and formers?

As far as I know, the fuselage is made in two halves just like a model kit, then glued & screwed together once most of the equipment has been installed. Or at least that's how I thought they were made during the war.

greg v.

[JDK]

Only the Canadians used concrete molds, they tried the wood ones like the brits, but decieded that concrete was better.

I'd like Bruce's input on this. Certainly the de Havilland Heritage Centre in the UK has a set of concrete moulds on show outside, which, IIRC were for the fuselage of a DH Hornet.

As to the other questions, this film shows many of the details:

Australian Mosquito production.

http://www.youtube.com/watch?v=D3mGOLmWWbg

What the propaganda newsreel fails to show was the defective workmanship and resulting delays and accidents that ensured most Australian Mosquitoes didn't get to combat in the war, unlike the British and Canadian production. One of the less glorious aspects of the story, sadly.

An American film of Canadian production.

http://www.youtube.com/watch?v=d7pNBSRk ... re=related

Shows a bomber version (Canadian prototype?) but the voice over also discusses the fighter version with cannon and machine guns.

HTH.

[Cvairwerks]

The Fairchild skins were done in pretty much the same manner. Each section was formed and cured. When it was time to assemble, the forward skins were bonded to built up frames installed on the tubing work and then butt seamed with a doubler applied to the seams internal to the fuselage. The aft skins were bonded the same way, but the frames were located in assembly tools. The bonded aft section was then removed from the tools and bolted to the end of the forward section.

Wing skins were molded and then prefit to the wing section prior to bonding. Once the center spars were installed in the forward section of the fuselage, the center section was built up with the exception of the nacelles and the skins installed. Once that was completed, the nacelles were done and so on.

Within the fuselage, the skins were painted after bonding was complete. The color was a mixture containing a forest green, a bronze and instrument black, giving it a weird color. I've got the mix spec in one of the books with my files.

[herkman]

The Canadians were not the only factory to use concrete moulds, HDH Australia went down the same track.

The disadvanatge of the wooden mould, as the NZ guys found out was that you have to store and keep them in a stable area or the humidity affects the accuracy.

Regards

Col

[Bruce]

Couple of points.

As I said, the early moulds were wood; de Havilland switched to Concrete later in the run as it was more stable. UK as well as Canada and Australia.

The DH Museum does indeed have some Hornet moulds on display.

The Green colour, on British Aircraft isnt a primer; it was just a standard colour for cockpits - and quite different to the American one.

As James rightly points out, the wing is pretty conventional; not much moulded plywood there!


Bruce

[JDK]

Just found another good set of films on the Mosquito incluing UK and Canadaian production. Good detail of the build at the start and 2:30 point.

http://www.youtube.com/watch?v=-cb6SmK_c2g

I love the guys hand-sawing out the bomb bay walls.

The Fairchild skins were done in pretty much the same manner. Each section was formed and cured. When it was time to assemble, the forward skins were bonded to built up frames installed on the tubing work and then butt seamed with a doubler applied to the seams internal to the fuselage. The aft skins were bonded the same way, but the frames were located in assembly tools. The bonded aft section was then removed from the tools and bolted to the end of the forward section.

Sounds interesting. Which Fairchild are you referring to? It sounds like a mixed construction or semi-monocoque, whereas the Mosquito fuselage was a complete monocoque.

More details? Pics?

[Rhino-9-3]

There's a video on our website about the manufacture of Mosquitos during the war. There is also a nice article about the first mould that was made by Powell for the Mossie Group here in Windsor. (And yes the first fueslage was made from non-airworthy grade material, that is why this one won't be flying.)

http://www.ch2a.ca/MainWelcome.html
(you have to scroll down the side menu to the Mosquito part)