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 Faded plastic
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 Return to top of page · Post #: 1 · Written at 8:03:55 AM on 5 July 2013.
Scraps's Gravatar
 Location: Blue Mountains, NSW
 Member since 10 March 2013
 Member #: 1312
 Postcount: 401

I've got a maroon AWA 573MA that's faded to a powdery brown colour on the top and sides. The bottom, back and inside are still a rich maroon colour. I've taken to it with some 1500 wet and dry in an inconspicuous area followed by Brasso which brings up a brilliant shine but still brown.

I've read about the retrobright process but I don't think that applies to these early plastics. The colour must still be there somewhere but I suspect it's very deep. Has anyone had success with bringing back the original colour on these or do I settle for a shiny brown?

Warren


 
 Return to top of page · Post #: 2 · Written at 8:54:15 AM on 5 July 2013.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7395

This is probably the worst colour to bring back to its best, speaking from experience. I have a 500 series Radiolette in the same colour and found that when lightly sanded to bring back the shine, all I ended up doing was removing the 'top coat' altogether and exposing the asbestos and wood filler material which makes the radio look like it has freckles. Only the base of that radio looks original, although from a couple of metres away the radio does still look good.

As far as colour goes, you may be out of luck and may have to settle for what is there. I wouldn't be tempted to cut back too much. Lots of furniture polish (Tonizone or Mr Sheen) will definitely help once sanding is finished.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 3 · Written at 7:13:52 PM on 5 July 2013.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6761

I don't know about that particular AWA case, but I have a maroon Kriesler Duplex that was badly heat faded on the tops of the sides. They were pinkish white.

I didn't think I'd be able to rescue it but I did manage it. I used 1200 wet and dry soaked in a dish of tepid water lubricated with a few drops of dish-washing liquid in it to cut it back, and finished it off with Autosol polish. Lots of elbow grease but it worked a treat.

The dial plastic on this set had gone translucent. I managed to get it back to clear using the same process -- and was amazed that it worked.

Here it is:

http://i169.photobucket.com/albums/u218/gtc_photos/My%20Radios/DSC02283.jpg.

(All I need now is a set of the correct knobs, but hen's teeth are easier to find.)


 
 Return to top of page · Post #: 4 · Written at 8:58:40 PM on 5 July 2013.
Scraps's Gravatar
 Location: Blue Mountains, NSW
 Member since 10 March 2013
 Member #: 1312
 Postcount: 401

The Kriesler's come up well. I might try going a bit deeper with the wet and dry, I'm not too sure about the composition of this mid 1950's plastic. I'm worried it's like bakelite where once you've gone through the surface and hit the fillers there's no recovery, as Brad mentioned. It does polish up quite easily after rubbing it back though.

Warren


 
 Return to top of page · Post #: 5 · Written at 11:07:02 AM on 6 July 2013.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7395

I'm sorry, I was to believe it was Bakelite and it looks like you are talking about thermoplastic. Thermoplastics (all types) definitely need a much softer touch. The thing to remember though is that with most plastics, Bakelite included, once discolouration goes right through the product it is permanent and thus cannot be reversed or recoloured.

Painting the affected areas will work but the painter would have to be an expert and would need to use a spray gun and use the most appropriate type of paint for the finish to be flawless.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 6 · Written at 2:43:02 PM on 6 July 2013.
Maven's Gravatar
 Location: Canberra, ACT
 Member since 23 August 2012
 Member #: 1208
 Postcount: 584

For painting over patches or streaks, where Brad says "spray gun" I would suggest air brush (mini spray gun) as found in model and hobby shops, also used by artists, vehicle detailers etc. A general purpose spray gun is very hard to control at detail level, as is the pressure-pack spray can.

Maven


 
 Return to top of page · Post #: 7 · Written at 11:36:06 AM on 8 September 2013.
Duconbuster's Gravatar
 Location: Riddells Creek, VIC
 Member since 7 August 2009
 Member #: 526
 Postcount: 123

I also have found autosol very useful on Kriesler plastics.....recently on an 11-81A foggy dial lens which it bought back as new. That era plastic cases seemed almost soft & flexible compared to others.....I have a bright orange Astor GPM which seems to made of a thinner more brittle feeling plastic. It's faded at the top & on the sides, is it a thermo or different type of plastic? Would wet & dry be the way to go. It has a beautiful marbling swirl in it which has made me reluctant to attempt anything so far. Oddly the case presents with an excellent shine even though it's faded.....previous owners have probably polished it.


 
 Return to top of page · Post #: 8 · Written at 7:55:24 PM on 8 September 2013.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6761

Would wet & dry be the way to go.

Very fine wet and dry, lubricated with dish washing detergent seems to work wonders on most plastic surfaces.

Nonetheless, I would be cautious. Are you able to test it out on the interior of the case?


 
 Return to top of page · Post #: 9 · Written at 10:15:42 PM on 8 September 2013.
Maven's Gravatar
 Location: Canberra, ACT
 Member since 23 August 2012
 Member #: 1208
 Postcount: 584

There's a product called PlastX available in auto parts shops mainly for polishing scratched plastic light lenses. It has worked well for me on modern plastics including iPod screens and white plastic computer bodies. I think it is basically fine clear filler that bonds into the abraded surface of a range of plastics more permanently than a car or furniture wax. Certainly polishes up well.

Maven


 
 Return to top of page · Post #: 10 · Written at 10:54:39 PM on 9 September 2013.
Duconbuster's Gravatar
 Location: Riddells Creek, VIC
 Member since 7 August 2009
 Member #: 526
 Postcount: 123

Might try the wet dry idea on the rear of the unit, top of the rear on one side only is faded oddly enough....
Thanks for the tips Whoa


 
 Return to top of page · Post #: 11 · Written at 12:14:22 AM on 10 September 2013.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6761

Make sure you use very fine (say 1200 grade), and take it easy to begin with. Use tepid water with a few drops of detergent as the wetting/lubricating agent. That ought to do the cutting ahead of the polishing.


 
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