A Messerschmitt blueprint of Bf 109G-4 plywood instrument panel shows a strange extension on the lower right corner of the panel. Does anybody have any idea which instrument it might be for? Anything for a FuG? The blueprint shows an early version of the G-4 panel. The second photo is of a G-4 panel which I made about a year ago from this blueprint.
I do not know which wood I used. However, I can learn it for you. Before I made this part, I saw the same part on the instrument panel of "Black 6" which had a strong reddish-brown color. So, I looked for a wood with a similar color and I found one at a store but I do not remember the type of the wood. I made it more than a year ago.
thank you for your answer, with reddish brown color, an assistance was, takes times to it around Mahagoni wood it acts. would be possible still further pictures of this for instruments board?
in reality, a stuff called "Durcoton" or "Pertinax" was used, same as for the instrument cases, also known as Bakelit!
It was a Phenol-resin with fabric.
By the way, the same stuff was used for the bearings of the landing gear buttons in metal panels!
Thanks Harald. I did not know that. I dont have the blueprint with me now but if I am not wrong it was saying that the material was plywood. Pertinax is very logical cause the plywood was breaking apart especially at the thin walls on the sides.
I remember very well that the blueprint of this part had "wrong" dimensions. It was overlapping with the tachometer!
Some remarks on Bakelite, Pertinax and materials like Durcotton.
They are all based on Phenolic resin, but there are some differences.
Bakelite is in principle an anisotrophic material, meaning that it's properties (strength, flexibility) are the same in all directions (like in normal metals).
Bakelite is composed of phenolic resin and any, or a combination of the following additives : asbestos, mica, wooddust, cellulose, shredded paper, shredded cotton.
Bakelite is in principle free-form, as it is pressed in moulds under very high pressure and moderate temperature.
Examples are the housings of a lot of the flight instruments that we are all so interested in, and the radio cabinets and electrical outlets and plugs up to the 1950s-60s.
In normal high quality bakelite, the additives like mica, asbestos, etc. are not really discernable, but if you look at some of the late war production instrument housings,
where the ratio of filling material apparently is higher than in earlier samples, presumably to spare on expensive phenolic resin,
and especially the ones one that have worn a bit, you can sometimes easily see the shreds of fabric that were used as a cheap filling material. (see attached picture)
The one exeption here is that bakelite was also produced in (thicker) sheetform for special purposes, but this was still an anisothropic material.
Pertinax, Durcotton, and similar products known under other 'brand' names are isothropic materials, their properties are different for the different directions of the material (like length and thickness).
This is the result of them effectively being 'layered' materials (like plywood).
Pertinax consists of (stacks of) sheets of paper drenched in phenolic resin, hardened under presure.
Durcotton is the same, but using sheets of cotton fabric instead of paper.
These sheet materials were produced in thicknesses ranging from paper-thin (thin pertinax used for isolation by riveting the material to the insides of metal housings to prevent the risk of short-circuits through the housing ), to fairly thick ( around 2 centimeters in thickness, mostly the cotton sheet based materials) that in the 1930-1940 airplane manufacturing are used extensively for the manufacturing of bushings (like the control-wire guides in many airframes) and foundation blocks and isolation plates for small equipment.
The material can be fairly easily sawed, machined and drilled, and holes in the thicker materials can be threaded using normal metal threads. The thicker varieties can even be machined into gear wheels.
This kind of material is generally indicated by the generic name of 'Kunsthars-Pressstof' (artificial resin composite) in the 'Erstazteillisten' (parts lists) for the different airplane models, but is often specified by it's brand- or trade-name in the production drawings and assembly lists, names like Ferrozell, Canevasit, Durcotton (and others).
The interesting detail here is that apparently the first two brand names are still manufactured today, 70 years later !
Pertinax is nowadays classified as 'Hartpapier' (hard-paper) and Ferrozell and Canevasit as 'Bauwwollhartgewebe' (hard-cotton-fabric).
I did attach a picture of a late war bakelite instrument housing that clearly shows the excessive amount of cheap cotton shred filling material.
Hope this helps,
Is the the material called "phenolic fiber" the same material what we are talking about? I attach a photo of it. THe second photo işs from the cockpit of Black 6. The material of the rohr under the prop pitch gauge seems to have the same texture.
you are right, this is the material, Marcel and I was talking about. As Marcel said it has different brand names, depending on the supplier. That one you have pictured is the right one, with fabric layers. There is another existing, called Pertinax, which comes in similar way, but with paper layers, instead of fabric.
Thanks. Thats great. Marcel mentioned the name Kunstharz-Pressstof'. For those who may be interested, the ring shaped parts (8-109.954-0113) where the landing gear rods pass thru on the Bf 109F and early G panels were also made from the same material Kunstharz-Pressstof Kl. G. DIN 7701.
This material also was used for the main panel of the HE 219.
7mm of "phenolharzgetränktes Buchenpresschichtholz".
You can see it at pictures of the Smithsonian´s 219.
It had a reddish colour before it was restored.