Spitfire color help requested: radio mast housing

[Seawinder]

Eduard's painting instructions for their 1/48 Spitfire Vc Trop show the ovaloid radio mast housing either painted in the surrounding camouflage color or in a dark wood color (they call out Mahogany). I presume this item was made of wood, but was there any rhyme or reason for its either being painted or not?

Thanks! Pip

[Troffa]

Here is a thread on this very subject! I hope it answers your query, and I hope I got the link correct.

You are up early, or is that late?

 

Spitfire antenna base thread

[Ossington 2]

I think it was made from Bakelite, or similar early 'plastic'.

[NZTyphoon]

22 minutes ago, Ossington 2 said:

I think it was made from Bakelite, or similar early 'plastic'.

Bakelite generally didn't weather well and could become brittle and fragile. The material for the mast's teardrop-shaped base insulator was more likely to have been a compressed paper/resin laminate material, with the trade name of 'Tufnol' (still being produced) 

Quote

...Tufnol also produced parts for the iconic Spitfire fighter aircraft, leading the way for Tufnol’s long established contribution to the aviation sector...

 

Colour for the component was generally a dark brick-red and it was never painted over in service. 

Incidentally, the so-called 'Bakelite' Spitfire seats were also made from a similar material.

Edited March 14 by NZTyphoon

[Seawinder]

5 hours ago, Troffa said:

Here is a thread on this very subject! I hope it answers your query, and I hope I got the link correct.

You are up early, or is that late?

 

Spitfire antenna base thread

Thanks Troffa! Up late (=early in the morning). The older I get (currently 77), the more night-owlish I seem to become.

[Tigerausfb]

I think it's Bakelite, that plate looks moulded. Tufnol and Paxolin are in sheet, rod or tube format. Tufnol would need to be milled. Bakelite is made in a different way, under high pressure in a mould, rather like our models are injection moulded. Agreed it doesn't  like being immersed under water for months due to the filler flour used but a solid bit like that plate would not become brittle and having had bits of Bakelite in the garden for years, surface pits rather than breaks down. Ekco, who used to be in Southend-On-Sea, would have had the capability as their machinery for making Bakelite domestic radio cabinets was not needed for that purpose during the war. Ekco made countless parts for radio during WW2 as well as military radio. GEC tended to use a darker chocolate brown Bakelite for their moulding. 

[Troy Smith]

 

 

Colour visible here on Seafire.

 

 

[Tigerausfb]

Just to follow up here and why I'm as certain as I can be that part is Bakelite, I've dug through Andrews collection of ancient electrical items.  I found a Bakelite kV meter which shows a pretty good colour match to the Spitfire/Seafire photos above. 

 

 

 

And here's some Paxolin sheets for comparison

 

 

This is made from compressed paper or cotton matting and resin. You can see a sawn edge here.

 

 

In the linked post above mention was made of a 5M Ohm insulation resistance, this Megger is the sort of thing is that resistance value would have been tested with, itself made from Bakelite.

 

 

Andrew

[Seawinder]

The Tamiya instructions in their Mk. I kit call for black for the plate. I take it that's in error? That also begs the question, was it the same arrangement for a/c (like the Mk. I) with strung wire antennas and lead-ins?

[Troffa]

Hello again Seawinder, I do like an excuse to have a good search around the archives, here's a great reference that I have just found, it's going straight in the library!

 

Spitfire Boffin-ry

 

 

[Seawinder]

On 3/14/2025 at 3:38 PM, Troffa said:

Hello again Seawinder, I do like an excuse to have a good search around the archives, here's a great reference that I have just found, it's going straight in the library!

 

Spitfire Boffin-ry

 

 

Brilliant, Troffa! So Tamiya isn't necessarily wrong with their black call-out for the insulating plate.

[NZTyphoon]

On 14/03/2025 at 23:23, Tigerausfb said:

I think it's Bakelite, that plate looks moulded. Tufnol and Paxolin are in sheet, rod or tube format. Tufnol would need to be milled. Bakelite is made in a different way, under high pressure in a mould, rather like our models are injection moulded. Agreed it doesn't  like being immersed under water for months due to the filler flour used but a solid bit like that plate would not become brittle and having had bits of Bakelite in the garden for years, surface pits rather than breaks down. Ekco, who used to be in Southend-On-Sea, would have had the capability as their machinery for making Bakelite domestic radio cabinets was not needed for that purpose during the war. Ekco made countless parts for radio during WW2 as well as military radio. GEC tended to use a darker chocolate brown Bakelite for their moulding. 

I beg to differ: for one, the factory drawing, below specifies: SEAL AROUND EDGES OF ITEM 547 [the insulator plate in question] WITH ELLISON'S GRADE 'A' PLASTIC COMPOUND  something that would not have been necessary had the insulator been made out of moulded Bakelite (the screws were also countersunk into the material and the heads covered with the same compound). 'Ellisons', btw, was the manufacturer of Tufnol: the company was renamed Tufnol in 1944, in honour of the product.

 

Secondly, Bakelite was an inflexible, fairly heavy compound that could fracture with stress or impact: why would an aircraft manufacturer use such a material on an external air frame component, where a certain amount of flexibility, as well as good weathering qualities would have been required. Quietly weathering in a garden would be a completely different to being exposed to the temperature extremes, UV radiation and other stresses associated with flight, especially at altitude or during combat manoeuvres. What sort of stresses would have been set up by the mast, alone under such conditions? Would a fairly shallow moulding of Bakelite have withstood such repeated stresses, without sooner or later, fracturing or shattering?

 

Thirdly, the cross-section of the insulator shows that it was a single, fairly shallow,  curved plate with chamfered edges, which suggests that it was milled to shape, nor was it a 'solid bit' of moulding, as suggested.

 

Tufnol (more specifically 'Whale Tufnol') was also used for Lancaster instrument panels and numerous other military applications so it was just as likely to have been used for the Spitfire's aerial mast insulator

 

 

 

Edited March 16 by NZTyphoon
Questions about bakelite

[Tigerausfb]

Morning,  well we both beg to differ. It would be remiss to mention I've collecting and working on military and civilian radio sets for 30+ years (hence the pile of vintage electronic junk) so I do have some experience with early plastics. Never mind anyway, I will find out

 

Andrew

[Troffa]

Hi Mr NZTyphoon, the plastic sealant around the faying edges and covering the fasteners is still seen today on modern installations, and is a waterproof seal to prevent any water getting past the assembly, including by capillary action, I don't think it points to any material specifications of either component, it's just cheaper than a gasket.

 

Cheers,

Troffa