Perspex as dial glass replacement material

[Bushbaby]

Hi All,
I don't believe I've ever seen this mentioned but has anyone tried this at all. Is it successful and how does plastic cope with dust attraction? Will the build up of static affect the radio?

Thanks

Rob

[Nick]

Perspex is made from polymethyl methacrylate, sometimes known as PMMA or just "acrylic". Trade names are Lucite, Perspex & Plexiglass etc.

Its actually quite soft and scratches easily.

I would use genuine polycarbonate - sometimes called Lexan - its far far more scratch resistant and will last far longer - its easy to cut straight lines by scoring & snapping...

I've used both Lucite & Lexan extensively in many projects (e.g. http://4hv.org/e107_plugins/forum/forum_....php?90019) - both are easy to weld & cut, but Lexan is much tougher - note you can polish scratches out of Lucite, but Lexan, once scratched (say by a craft knife) is difficult to get clear again.

I'd buy a bit of each from eBay and see how you get on.

Both are easy to weld (note you don't glue this stuff, you chemically weld it) with chloroform or, nowadays, something like Polyweld (which is what I use).

Regarding static, you can get anti-static sprays to reduce dust pickup... Google is your friend here

[Robert Darwent]

I don't believe I've ever seen this mentioned...

Rob,

For example, the dial on the Ekco A22 was made from Perspex or at least something very much like it, add to that quite a few 1950 valve portables that favoured it instead of glass. Its use in vintage radios is more widespread than you may have thought.

...how does plastic cope with dust attraction? Will the build up of static affect the radio?

In my experience, no different to a genuine glass dial as regards attracting dust. As for static being an issue with the functioning of the radio - in a word 'no'.

Regards

[Radio Fixer]

If its glass and a simple shape I would stick with glass ... square and even round are cheap to have cut.

I have made several moulded ones used in US radios from acrylic sheet. Its not too difficult a technique to master, actually fun, and I have written about it if thats what you are interested in.

Gary

[Yorkie]

Polycarbonate is shatter-proof.

We've just bought a sheet of clear to use as a safety screen for our lathe at the woodturning club from a well-known firm which - on internet trades as 'The Plastics People' (AKA 'Barkston's). The sell a very wide range of just about every type of plastic available in sheet, tub, rod, in a wide range of colours as well as clear. A committee member of our club runs a light engineering firm and has a trade account with Barkston's Hull branch. He arranged for a price for the polycarbonate sheet we need, and was quoted a prices in excess of £100 plus VAT. It sounded expensive to me so I went on their 'Plastics People' website, where you enter your requirements and get an instant quote. The quote was £55.00 inc VAT. My chum was not best pleased, and after a bit of haggling on the phone, got them to honour the internet price. If nothing else, this demonstrates that on internet, where all the buyers can see what all the suppliers are charging for identical commodities, (what economists call a 'perfect market'), competition drives down prices. Local suppliers on the other hand, charge what the market will stand.

Well worth a browse, especially at the special offers and clearance lines.

http://www.theplasticpeople.co.uk/

As Gary says, if it's just a flat screen, why not use glass. Local glaziers are very obliging and charge a pittance, even if you need holes drilling, leastways they do around here.

[Bushbaby]

Hi All,
Many thanks for your comments.
I'm thinking of my VHF90 which has holes in the glass for the tuner and volume controls. I think that it would be nigh on impossible to do this well in glass without breaking it.

Regards

Rob

[Radio Fixer]

Basildon Glass can drill the holes for you. Did for me for an HMV650 (and put on a beveled edge. I guess they can even do odd shapes as they have NCR cutting. 'Cause it may be a little too expensive for you.

Gary

[Skywave]

Somewhere, sometime I have heard that with a sharp pair of scissors you can cut (thin) glass if you do the entire operation under water: I've never tried it. Has anyone here tried that? . . . Or is it just another 'urban myth' - as I suspect?

Al.

[pwdrive]

Hi Al, not very well I would have thought, conchoidal fractures and all that.

Lawrence.

[Bushbaby]

Hi Gary,
I have no idea of cost - can you give me an idea of what you had made and how much they charged? The holes in the VHF90 are about 15mm at least.

Thanks

Rob