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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
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15th Jan 2023, 11:16 am | #1 |
Dekatron
Join Date: Apr 2019
Location: Worthing, West Sussex, UK.
Posts: 6,604
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Cleaning/Polishing of Tape Heads Using Metal Polish
Is this a valid servicing method ?
David |
15th Jan 2023, 11:27 am | #2 |
Octode
Join Date: Dec 2017
Location: Morden, Surrey, UK.
Posts: 1,560
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
Yes.
Brasso. |
15th Jan 2023, 11:53 am | #3 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,966
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
Should be fine so long as you don't overdo it. Take great care not to contaminate any bearings though.
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15th Jan 2023, 12:07 pm | #4 |
Pentode
Join Date: Nov 2020
Location: Bristol, UK.
Posts: 152
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
Record heads can withstand more wear than replay ones, and erase heads more again. This is because of the mechanical construction of each type of head.
I'd be very gentle with replay heads, especially if they have a significant wear pattern (i.e. an obvious notch and/or irregularities where the tape passes over them). Use isopropyl alcohol in the first instance, as some lamination lacquers are soluble in meths. I'd use metal polish as a last resort (on rep heads). Also keep metal tools away from them, as scratches can mess with the audio pickup. I'm not saying it won't help, mind, especially if they are really crusty. Obviously, too, the slower the tape speed and the narrower the tracks, the more the above applies. |
15th Jan 2023, 12:51 pm | #5 |
Octode
Join Date: Mar 2016
Location: London, UK.
Posts: 1,050
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
I haven't tried it myself, but I wonder if wadding polish might be better than Brasso liquid, as it's less abrasive?
If you are nervous about the abrasive media in the polish being too fierce, there is the Tamiya polish for using on models, i.e. aircraft canopies. The finest one is the 'finish'. I've used it on VU meters with very soft lenses (a particular lens I've seen dissolves when touched with IPA! You only have to look at it and it's scratched). Works a treat, but the 'finish' one is very time consuming as it's so gentle. https://www.tamiya.com/english/products/87070/index.htm NB - I have never gone near a tape head with an abrasive media, so the above are suggestions I haven't tried. I have a deck that has a yellow-ish discolouration around the heads (from Japan, and I suspect it's oxidisation due to humidity), but the heads are devoid of grooves and appear to have been replaced at some point. I was thinking about getting the 'Duraglit' (wadding - now rebranded as Brasso) polish on them... edit - I've read the toothpaste is too abrasive for heads. Be warned! |
15th Jan 2023, 1:59 pm | #6 |
Octode
Join Date: Jul 2006
Location: Perth, Western Australia
Posts: 1,969
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
In normal use, the head face is kept polished to a high degree by the tape itself. So normally the need to merely restore the highly polished finish should only be because the head face has become a little corroded for example and no longer mirror-like.
Another cause of corrosion or erosion especially on open reel machine heads seems to be playing a "Sticky Shed" tape and then failing to remove the sticky deposits before storing the machine. In my experience, over some time the moisture attracting substance (hygroscopic) can make a real mess of the head face. In one case the corrosion cut so deep into the Revox play head's alloy surface that I had to replace the head. I have an Otari machine with me now which also had some thick Sticky Shed deposits on the heads. Fortunately the muck hadnt been long on the heads (maybe it being summer and dry over here has also helped) so after a good clean the head faces though worn were found to have almost no corrosion. Photo of Sticky Shed muck before it was removed. Last edited by TIMTAPE; 15th Jan 2023 at 2:17 pm. |
16th Jan 2023, 12:15 am | #7 |
Octode
Join Date: May 2007
Location: Liss, Hampshire, UK.
Posts: 1,875
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
If a head needed that sort of abrasive treatment I'd probably send it off to Terry at Summertone so that it could be properly re-profiled.
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16th Jan 2023, 1:45 am | #8 |
Banned
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 2,704
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
Some of these methods remind me of a 12" ******* file and lots of elbow grease.
Heads "should " be mirror finish, or nearly so. Cotton buds and head cleaner is what I have always used. That being said, when I worked for Akai I was taught to lap heads on a surface plate specifically for tape heads. The photos from tim show pretty normal gunk that is easily cleaned with head cleaner, OR if its difficult to obtain, VCR head cleaner smells the same ( I dont know its formulation !! ) and is still around. Heads are extremely delicate, even if treated with respect. Joe p.s. a b-a-s-t-a-r-d file is just that. Its a course cutting tool. Last edited by joebog1; 16th Jan 2023 at 1:46 am. Reason: stupid Google spell check |
16th Jan 2023, 4:37 am | #9 |
Heptode
Join Date: Jan 2008
Location: Ashhurst, Manawatu, New Zealand
Posts: 571
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
I used the last bit of a roll of cloth tape that our secretary uses to secure documents. It's 1/4" wide +/- a few thou and wound onto a 5" reel does a wonderful job of cleaning everything in the tape path. A dribble of IPA through one of the reel slots gives a wet then dry effect and by the time the tape has gone through most of the IPA has evaporated so it then gets a polish with the tape turned over. Goodness knows where you would buy the stuff - it doesn't look like it's wearing out!
__________________
Cheers - Martin ZL2MC |
16th Jan 2023, 6:54 am | #10 |
Octode
Join Date: Jul 2006
Location: Perth, Western Australia
Posts: 1,969
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
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16th Jan 2023, 9:59 am | #11 |
Nonode
Join Date: Jun 2013
Location: Surbiton, SW London, UK.
Posts: 2,801
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
To clean a head in regular use methanol should be satisfactory.
To remove metal tarnish a fine polish, e.g. Greygate DTD770A plastic polish works well. Bakelite paste e.g. No.5 deals with more severe corrosion. Re-lapping (grinding) is only required when the head profile is so poor that the polepieces are not flush with the main head surface. Only works once or twice. |
16th Jan 2023, 10:06 am | #12 |
Banned
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 2,704
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Re: Cleaning/Polishing of Tape Heads Using Metal Polish
As resoration has said. If the pole pieces dont "meet " in the gap, the head is finished. No amount of polishing will restore a totally warn head.
If you dont know what I mean, it should be available on the net. Joe |