TO – we have something else in common

I spent a year early in my education as a polymer processing technician – which included compounding rubber from scratch on a 2 roll mill and a Winkworth. As well as spending part of my degree in polymer science.

Later I spent three years developing high tear strength silicone rubbers including transfer to production – hence my geekiness in this area.

TO – can I add to your summary:

There are 3 main forms of carbon – graphite, diamond and fullerenes.

Compounding of natural rubber uses a reinforcer of carbon black- which is in effect – – burned carbon products. Of all the forms of carbon it is most approximate to graphite. Without it – vulcanised natural rubber products are very weak. It is also why most tyres are black.

Graphite is a series of thin monolayers of carbon – loosely joined to otehr layers – which allows them to slide lubricate and conduct.

Silica and silanes are two separate compounds. Silica is a hard powder – which is used in the reinforcement of silicone rubbers and as a diluent in other elastomers.

Silanes are reactive silicone compounds which can be used to treat fillers and fibres to allow them to bind to organic substances. e.g. in tyres silanes are used to treat the fibres to allow them to bind in to the rubber. Silanes are small molecules based on silicone. Burning silicones – like carbons to give carbon black – gives silicas.

geek mode off

but he has got away with using Araldite resin, mixed with some black paint. .

Should have mentioned that I am a chemist – Araldite is a trade name of a 2 part epoxy resin – as mentioned above.

The epoxy group is in the clear part and the triamine compound is in the smelly darker second part.

If you have the broken piece – stick it back on with super glue – thick viscosity.

If you dont have the piece – I would use epoxy filler – metal body filler or metal putty. and sand down to the correct surface.

If the break is smooth and there is no keying – scarify the surface to get somewhere for the epoxy to stick too.

Bakelite is a phenol formaldehyde thermosetting resin. Epoxy Resin is a thermsetting resin of an epoxide and an amine.

Not an exact chemical match – but both have similar plastic structures.

PM sent

I am an apprentice clock geek and have around 10 at any one time.

The reference books are easy – Whitney for American clocks and Knirim for both German and British clocks.

The designation of which clock was used on which aircraft is subjective as most were general purpose.

Where to buy -there are usually a couple at NAM Aeroboot as well as Shoreham.

Some military dealers have some – Tiger Collectibles ; CJ Balm, Bomphoons etc.

Ebay is useful but you have to be careful- especially if you want working ones.

Generally Prices have doubled in the last 5 years. Only by experience will you know what is the right price.

On what clocks to have – the British are nice but you will struggle to get a full collection as the Mk3 are expensive and the mk1 extremely extremely rare (only used in a couple of Flying Boats).

Also there are very few people prepared to fix the Smiths clocks 2B, 2C, 2D and Mk 4, 5. The Mk2 Jaeger Le Coultre is expensive and repairable.

German clocks – are again nice – there are several types of the so called 109 clocks so you can be busy for a while. Several stalls at Speyer have them – but clocks in Germany are collectible and expensive.

I have had Junghans 109 clocks but as they are only 1 day clocks – As I am away a lot – I have restricted myself to 8 day clocks. I keep all my clocks running.

There are several US types – the A11 , A13, CDIA, Hamilton Elgin etc.

There are the Russian clocks – avoid the 2 day and restrict your self to the 5 or 8 day versions (far better mechanisms).

It all depends what you want to do with them.

I have also progressed to US Military ships clocks – Chelsea, Seth Thomas (and Max Low).