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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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16th Mar 2023, 12:09 pm | #1 |
Pentode
Join Date: Feb 2018
Location: Cheshire, UK.
Posts: 121
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Use of MEK to restore idler wheel?
I have an idler wheel from a BSR 810 deck that has become hardened. I've seen threads that advise the use of methyl ethyl ketone to restore hardened rubber components. I'm wondering what the best way to apply the MEK would be. Should I immerse the wheel in the MEK? If so, how long for?
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16th Mar 2023, 1:47 pm | #2 |
Nonode
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
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Re: Use of MEK to restore idler wheel
MEK is a rubber restorer used in the offset litho print industry. It is very effective, but immersion is not a good idea. spin the idler and apply MEK with a cloth or cotton bud. Acetone has a similar formula and works quite well - also less toxic !
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16th Mar 2023, 4:15 pm | #3 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
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Re: Use of MEK to restore idler wheel
MEK is an exceptionally powerful solvent; I wouldn't go anywhere near a rubber idler wheel with pure MEK.
Whether MEK in low concentration in some other medium might be be effective is possible. B
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17th Mar 2023, 12:58 am | #4 |
Nonode
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
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Re: Use of MEK to restore idler wheel
I used it for many years when I was a printer to revive the rubber blanket of an offset litho machine. Acetone, however, is a more sensible domestic option simply because it is so common - nail varnish remover.
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17th Mar 2023, 10:11 am | #5 |
Dekatron
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Location: Worthing, West Sussex, UK.
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Re: Use of MEK to restore idler wheel
Personally I have had minimal success but some people say they have had good success with reviving/softening hardened rubber idler wheels using Glycerin.
David |
17th Mar 2023, 11:13 am | #6 |
Dekatron
Join Date: Aug 2003
Location: near Reading (and sometimes Torquay)
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Re: Use of MEK to restore idler wheel
I would not have expected MEK or acetone to be a good idea for idle wheels.
My understanding is that MEK is a solvent for rubber - but rubber is very cross-bonded so rather than dissolving the rubber it more likely dissolves into it. I think the offset litho folks exploits this to deep clean their rubber sheets and revive the surface. I have read that acetone will swell rubber worse than MEK. I have always used alcohols for cleaning rubber - like ethanol, propanol or brake fluid. I did once manage to soften some hardened rubber by soaking in brake fluid. |
17th Mar 2023, 12:52 pm | #7 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
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Re: Use of MEK to restore idler wheel
Glycerine fixed the surface of the rubber-coated metal disc of the variable speed adjustment mechanism of my Eumic cine projector. It worked by adjusting the radial distance at which a polished steel ball pressed against the rubber on the disc. The rubber had become shiny, resulting in slipping. Smearing the rubber surface with glycerine, leaving it for a few minutes, and then cleaning it off with water, completely restored grip to the rubber.
Last edited by emeritus; 17th Mar 2023 at 12:53 pm. Reason: typo |
17th Mar 2023, 1:53 pm | #8 |
Dekatron
Join Date: Sep 2007
Location: Oxfordshire, UK.
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Re: Use of MEK to restore idler wheel
Glycerine also softened the rubber surrounds on some vintage KEF B139 drivers I had. Their specified free-air resonance was at 25+/-5Hz and, presumably, when new the surround was compliant enough that they achieved this (one of KEF's datasheets says that the typical production spread was +/-2.4Hz). After 40-50 years the rubber had stiffened enough that the resonances I measured were more like 35-40Hz. Gently rubbing glycerine into the surround couldn't quite get them back to 25Hz, but it did get them comfortably below 30Hz.
Cheers, GJ
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17th Mar 2023, 2:31 pm | #9 |
Banned
Join Date: Dec 2022
Location: Peterborough, Cambridgeshire, UK.
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Re: Use of MEK to restore idler wheel
MEK, the railway modeller's adhesive of choice for decades as it welds hard polystyrene together beautifully.
It also stuck the tops onto my chemistry teacher's pens exceptionally well, as he discovered when he taught me in particular about ketones. |
17th Mar 2023, 2:32 pm | #10 |
Dekatron
Join Date: Apr 2019
Location: Worthing, West Sussex, UK.
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Re: Use of MEK to restore idler wheel
The only time I have ever used MEK was long time ago, used it to clean ends of ABS pipe before bonding the pipe to ABS fittings using ABS cement.
David |
17th Mar 2023, 2:36 pm | #11 | |
Nonode
Join Date: May 2004
Location: Halifax, West Yorkshire, UK.
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Re: Use of MEK to restore idler wheel
Quote:
Alan |
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17th Mar 2023, 3:07 pm | #12 |
Octode
Join Date: Jul 2011
Location: Staffordshire Moorlands, UK.
Posts: 1,479
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Re: Use of MEK to restore idler wheel
I'm sure you all know this but keep brake fluid away from painted surfaces
Steve.
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17th Mar 2023, 4:17 pm | #13 |
Pentode
Join Date: Jul 2007
Location: London, UK.
Posts: 165
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Re: Use of MEK to restore idler wheel
For cleaning and restoring the grip on idlers and pinch rollers I have had great success with Platenclene a product designed for print rollers. I have been using this for nearly 20 years and unlike most solvents it does not degrade the rubber over time.
Colin |
17th Mar 2023, 8:36 pm | #14 | |
Dekatron
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Location: near Reading (and sometimes Torquay)
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Re: Use of MEK to restore idler wheel
Quote:
As I said, alcohols (i.e. things with OH groups) seem to be safe. Ethylene glycol and glycerol both fall into that general category. |
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17th Mar 2023, 10:11 pm | #15 |
Hexode
Join Date: Sep 2008
Location: Charlton Mackrell, Somerset, UK.
Posts: 315
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Re: Use of MEK to restore idler wheel
I've had varying success with MEK on idler wheels and rubber roller. I've found lightly roughing the rubber with wet and dry paper helps the softening process. Be careful with MEK it is carcinogenic.
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17th Mar 2023, 10:52 pm | #16 |
Dekatron
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Location: Lynton, N. Devon, UK.
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Re: Use of MEK to restore idler wheel
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17th Mar 2023, 11:30 pm | #17 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
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Re: Use of MEK to restore idler wheel
I thought the problem with MEK was that if you smoked a cigarette when using it, the glowing end was hot enough to break down the vapour to form a highly toxic gas.
After the potential health problems with MEK were identified, someone produced a plastic solvent called MEK PAK. I forget what it contained, but the bottle said it was not MEK. Nonetheless, I did buy a small bottle of genuine MEK at a pre-Covid model railway exhibition. I actually wanted Plastic Weld (dichloromethane), but the stall only had MEK. Last edited by emeritus; 17th Mar 2023 at 11:44 pm. |
18th Mar 2023, 12:01 am | #18 |
Heptode
Join Date: May 2005
Location: Adelaide, South Australia
Posts: 541
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Re: Use of MEK to restore idler wheel
I didn't ever think to use MEK as a product to restore idler wheels - explains why it causes rubber gloves to swell - I've used it many times to help clean laminations when repurposing transformers, it turns even the most stubborn varnish soft so it can be scrubbed off - not a pleasant job - rubber gloves swell and eventually become so soft they break so I've stopped using them. If it is a carcinogen then having it so readily available doesn't make sense, I can get a 4lt tin filled at the local autopaint supplier.
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18th Mar 2023, 12:51 am | #19 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,349
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Re: Use of MEK to restore idler wheel
Just checked the label on my small bottle of MEK. Nothing about it being a carcenogen, just warnings about highly flammable vapour, use in well-ventilated room, do not smoke, vapour harmful by inhalation.
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18th Mar 2023, 12:20 pm | #20 |
Octode
Join Date: Jul 2014
Location: Petersfield, Hampshire, UK.
Posts: 1,043
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Re: Use of MEK to restore idler wheel
What method do you use Colin ,just wipe the rubber or soak etc ?
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