Cossor 378 Receiver. Warped Tuning Scale.

[jelida]

Hi Group,

I purchased a restorable Cossor 378 receiver in my local auction this week. The plastic tuning scale has become warped over the years, and I would like to flatten it if I can. Does any-one have any advice? I have tried softening it with a hair-dryer, but not hot enough. I could use an electric paint stripper, but I dont know how it would respond.
Also the grille-cloth is vary grubby. Any handy hints?

regards,
Jerry

[ekcobeach]

Hi Jerry, I have had success with warped celluloid dials by sandwiching between two sheets of clean paper and applying a medium hot iron.Once heated up place a heavy flat item and on top until cool.Works for me on Ekco dials. Regards, Colin.

[Hermit6345]

I had a similar problem with a deformed plastic scale for my Cossor 3733. I was afraid that I might damage the silk screen printing on my scale if I tried to flatten it. I therefore scanned it into the computer and made another. My original plan was to use waterslide transfer onto some 1mm thick perspex, but I changed my mind as the registration of the scale and the radio pointer meant that it was diffcult to do that. I finally printed it, in reverse, onto some transparent drafting film and then mounted this in front of the the 1mm perspex. I think it looks OK. I was easily able to make slots in the film to move it about once the radio had been offered up to the scale. Whilst it was still a file in the computer, I used MS Paint to clean it up as the original was very yellow. I still have the original and have put heavy weights on it but it still firmly resists going flat. I have not tried heat yet. Might be a good idea to make sure that you have a copy before you try to flatten it, as you might damage the original in the flattening process. I replaced my grill cloth with new as the original was very grubby indeed.

Ian.

[kalee99]

Hi,
I have not had much success with flattening these either. I think the celluloid they are made with is very unstable. Indeed the worst thing you can do is to try and warm it over a naked flame Flash woof and it is gone with only a small amount powder left. I remember making crude fireworks out of celluloid cinema film until I blew up Mothers old poss tub
Paul.

[Baggrus]

Same warning also goes for the yellow celluloid imitation bone handles used on EPNS cutlery. I had a shock many years ago when the handle of a knife I was using for some plastic welding virtually exploded on the gas stove with a brilliant white flame like magnesium, and a roaring sound.. It left a small pile of very fine white powder, just like wood ash. I'm just glad it went off on the stove and not in my hand...... Mind you.. the plastics and explosives industries were very closely linked in the early days.

I had some success with flattening celluloid in the same manner as warped vinyl lp's. Sandwich between 2 flat sheets of metal with bulldog clips and then hold in the steam from the kettle for a while. Suddenly everything will go flat, then just leave to cool. No risk of overheating or fire that way

[jelida]

Thanks all for your replies; I will scan it first, then try steam, then the iron if necessary. I have to say I'm also rather tempted by the idea of the magnesium type flame, but I'll reserve that for a special occasion.
regards,
Jerry

[jelida]

I have to say that the metal sheets, bulldog clips and steam method worked superbly!
regards,
Jerry