Cloudy/Yellowed TR82 Dials - UK Vintage Radio Repair and Restoration Discussion Forum

Tractionist · 19th Apr 2023, 9:15 pm

Someone posted a question as to whether the 'Restobright' process worked on [formerly but now cloudy/yellowed) Bush TR82 tuning dial 'knobs' - but I couldn't locate the OP (sorry mods).

Well, I have a few of these - some of which I've attempted to re-cut with appropriate paste hitherto - without success. But fuelled with 'the joys of Spring' and abundant sunshine - I thought I'd give one the 'Restobright' treatment.

Result! It does seem to work and certainly doesn't do them any harm. I've got one 'cooking' at present and it certainly seems to be much improved.

Unfortunately I didn't take any 'before' photos - but if anyone is interested I will post some 'after' shots.

Philips210 · 20th Apr 2023, 7:28 pm

That's good to know Retrobright works.

I've had limited success with paint cutting paste such as T cut when the yellowing is only slight. For very discoloured dials I've used a very fine wet and dry abrasive paper, typically 1200 or 1000 grit and then progress to a cutting compound. It can take a fair old effort to obtain good results but should be successful given a little patience. Brasso may be worth trying too.

Regards,
Symon

paulsherwin · 20th Apr 2023, 9:27 pm

Cutting compounds don't work because the discolouration is too deep. I didn't know that the Restobright process works with cloudy transparent plastic - thanks for the info.

locknut · 21st Apr 2023, 4:32 pm

Certainly good info, I wouldn't have thought to try that.

Tractionist · 21st Apr 2023, 9:47 pm

Attached progress to-date - it's not perfect, but greatly improved ..... this was a particularly 'sad specimen' featuring some sort of etched or superglue type staining on the outer face too (so I cut and polished it after the Restobright treatment.

Tractionist · 22nd Apr 2023, 11:56 am

A couple more shots for your routine edification:

19th Apr 2023, 9:15 pm	#1
Tractionist Heptode Join Date: Apr 2016 Location: Cheltenham, Gloucestershire, UK. Posts: 853	Cloudy/Yellowed TR82 Dials Someone posted a question as to whether the 'Restobright' process worked on [formerly but now cloudy/yellowed) Bush TR82 tuning dial 'knobs' - but I couldn't locate the OP (sorry mods). Well, I have a few of these - some of which I've attempted to re-cut with appropriate paste hitherto - without success. But fuelled with 'the joys of Spring' and abundant sunshine - I thought I'd give one the 'Restobright' treatment. Result! It does seem to work and certainly doesn't do them any harm. I've got one 'cooking' at present and it certainly seems to be much improved. Unfortunately I didn't take any 'before' photos - but if anyone is interested I will post some 'after' shots. __________________ Red to red, black to black. Throw the switch and stand well back!

20th Apr 2023, 7:28 pm	#2
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,450	Re: Cloudy/Yellowed TR82 Dials That's good to know Retrobright works. I've had limited success with paint cutting paste such as T cut when the yellowing is only slight. For very discoloured dials I've used a very fine wet and dry abrasive paper, typically 1200 or 1000 grit and then progress to a cutting compound. It can take a fair old effort to obtain good results but should be successful given a little patience. Brasso may be worth trying too. Regards, Symon Last edited by Philips210; 20th Apr 2023 at 7:31 pm. Reason: correction

20th Apr 2023, 9:27 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,156	Re: Cloudy/Yellowed TR82 Dials Cutting compounds don't work because the discolouration is too deep. I didn't know that the Restobright process works with cloudy transparent plastic - thanks for the info.

21st Apr 2023, 4:32 pm	#4
locknut Pentode Join Date: Mar 2022 Location: Retford, Nottinghamshire, UK. Posts: 173	Re: Cloudy/Yellowed TR82 Dials Certainly good info, I wouldn't have thought to try that. __________________ Paul

21st Apr 2023, 9:47 pm	#5
Tractionist Heptode Join Date: Apr 2016 Location: Cheltenham, Gloucestershire, UK. Posts: 853	Re: Cloudy/Yellowed TR82 Dials Attached progress to-date - it's not perfect, but greatly improved ..... this was a particularly 'sad specimen' featuring some sort of etched or superglue type staining on the outer face too (so I cut and polished it after the Restobright treatment. Attached Thumbnails __________________ Red to red, black to black. Throw the switch and stand well back!

22nd Apr 2023, 11:56 am	#6
Tractionist Heptode Join Date: Apr 2016 Location: Cheltenham, Gloucestershire, UK. Posts: 853	Re: Cloudy/Yellowed TR82 Dials A couple more shots for your routine edification: Attached Thumbnails __________________ Red to red, black to black. Throw the switch and stand well back!