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Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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29th Apr 2009, 12:53 pm | #21 |
Hexode
Join Date: Dec 2006
Location: Norwich, Norfolk, UK.
Posts: 440
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Re: cleaning tuning capacitors
ok
Just to play devils advocate here, how about one of those ultrasonic cleaners ? Jewelers sell them for cleaning intricate rings, chains etc, might have a better effect, and might be able to be used with a safewash ?? type of solution, that wont damage the metal parts. |
29th Apr 2009, 1:09 pm | #22 |
Retired Dormant Member
Join Date: Oct 2003
Location: Leicester, UK.
Posts: 143
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Re: cleaning tuning capacitors
Been there, tried that! With the jeweller's type one problem is that the bath tends to be quite small and not terribly deep, so it's difficult to get a normal size ganged cap into it. To immerse and clean every bit of the cap, you usually have to do it once the right way up and again upside down. The machines also tend not to be very powerful, so it can take several goes to get the cap clean. I admit, I've only used water plus detergent rather than a 'proper' cleaner (whatever that might be), so maybe I haven't really given the machine a fair trial. Nor have I used a bigger, professional-type machine. However, all I can say is that in my experience the dishwasher route is definitely superior to the type of jeweller's ultrasonic cleaner that's readily available.
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29th Apr 2009, 7:11 pm | #23 |
Retired Dormant Member
Join Date: Nov 2008
Location: London, UK.
Posts: 49
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Re: cleaning tuning capacitors
Do pubs still use ultrasonic glass cleaners? They always struck me as being most unhygienic but a friendly local bar person might dunk your cap for you if the boss isn't around!
PC |
29th Apr 2009, 9:10 pm | #24 |
Tetrode
Join Date: Apr 2009
Location: Towcester, Northamptonshire, UK.
Posts: 92
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Re: cleaning tuning capacitors
I use baking powder in disolved in hot water. Immerse the capacitor with vanes open and leave for an hour. The capacitor comes out very clean. I got the idea from an old RSGB publication. I rinse under cold water when clean and dry with a hair dryer. Then grease the bearings. To keep them clean in storage, I store them in the re-sealable food bags you get in supermarkets.
Neil.
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An engineer makes for a penny what a scientist makes for a pound! |
30th Apr 2009, 8:31 am | #25 |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
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Re: cleaning tuning capacitors
I do have a large ultrasonic cleaner that I use for clock parts, which will easily cater for the largest tuning gang that you can find; however, I still use the dishwasher.
When you repair a US cleaner as I did when I got it, the standard test is to stick a piece of cooking foil in for ten minutes, with just water. It should resemble a lace curtain if it's working. Verb sap
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Mike. |
30th Apr 2009, 2:19 pm | #26 |
Hexode
Join Date: Jul 2008
Location: Toulouse, France
Posts: 406
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Re: cleaning tuning capacitors
Hi !
To grease the center contact, use what I think you Brits call petroleum jelly. It is used during aircraft manufacture to ensure perfect contact (it is conductive) and resist chemical aggression. You can use it also on the car's battery poles to get them perfect. the only problem is when you go to the chemist to buy one tube... |
30th Apr 2009, 2:33 pm | #27 |
Rest in Peace
Join Date: Dec 2008
Location: Burton upon Trent, East Staffordshire, UK.
Posts: 1,686
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Re: cleaning tuning capacitors
Petroleum jelly usually comes in a nice big tub marked Vaseline, although there are other 'own brands'. It is used on car battery terminals but that's generally to combat corrosion. I've no reason to believe it's conductive as it was extensively used in the manufacture of lead sheathed long-haul telephone cables way back when.
Alan |
30th Apr 2009, 2:43 pm | #28 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,861
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Re: cleaning tuning capacitors
More about Vaseline/Petroleum Jelly here: https://www.vintage-radio.net/forum/...ad.php?t=33174
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1st May 2009, 10:49 pm | #29 |
Pentode
Join Date: May 2009
Location: Stockton-on-Tees, County Durham, UK.
Posts: 154
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Re: cleaning tuning capacitors
be careful cleaning a tuning capacitor made of aluminium with caustic soda as it can produce hydrogen
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4th May 2009, 8:55 am | #30 |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
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Re: cleaning tuning capacitors
Vaseline is not conductive at all - it does resist acids, though, hence its use for battery terminals.
It is not a very good lubricant as a heavy grease for things like tuning gangs, though. When these devices were new, the grease used was a brown colour, and quite thick.
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Mike. |
5th May 2009, 4:53 pm | #31 |
Retired Dormant Member
Join Date: May 2008
Location: Preston, Lancashire, UK.
Posts: 428
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Re: cleaning tuning capacitors
Here is a different method that I have always found very effective, but you may regard it with some suspicion.
I play the flame of a small gas blowtorch between the vanes. This reduces any dust to ash very quickly and the residue it easily blown away or washed away. I don't mean heat the thing up until it is red hot. You have to be careful about any paxolin, but brushing the flame quickly across it in less than a second will usually clear it. Bob |