How to Clean Audio Cassette Heads

When the heads are that badly contaminated, it's virtually impossible to get them clean without a small degree of scratching occuring. I usually use a plastic scraper to get the bulk off. The bit of a ball-point pen cap that clips over your pocket is usually good for it. Sometimes, with stubborn cases, some wadding-type metal polish will shift the oxide, but I'm afraid that occasionally, the oxide / corrosion is so firmly attached, that you just have to go for it and use a metal scraper, such as a blunt scalpel blade. It does leave some light scratching to the head surface if it's a standard metal type, but the chances are that this will be insignificant compared to the performance degradation it will already have at that age, from basic head wear. I'm not sure that rubbing alcohol is really pure enough for electronics use. It should really be 99.7% ( electronics grade ) isopropyl alcohol.

Arfa

Firstly, rubbing alcohol contains carnuba wax, which leaves a residue. I use isopropyl alcohol (over 90%) and for really crusted on grime, I use the little plastic bread bag closure tags as scrapers. Regards Lee

The common practice in Aviation repair shops to freshen up flight recorder heads that are scratched is to use Micromesh, a extremely fine abrasive. I'd assume it would be just fine on any magnetic tape head. Start with a 2400 grit, knock the worst off and then go up to 3600 and finish up. Also adjust the Azimuth, there should be screws on either side of the tape head to ajust the tilt of the head, if the Azimuth is off the sound will be noably lacking in treble and have a muffled sound.

One source for Micromesh-

Jammy

Not all rubbing alcohols are created equal. Some are just isopropyl alcohol and water.

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Auto reversing decks commonly have the problem of unequal playbacks, that why I always stayed away from them. It sounds like a tuneup is necessary, by making adjustments so the playback sounds similar.

That sounds like the best way of removing the corrosion. I once tried lapping a head. I was doing good, but then I really ruined it I will never figure out why my brand new reel to reel had a bad head. It was a floor unit, but was sold as new. I thought it was just me that the tapes were being eaten by the machine, and the tapes were expensive on those 10 inch metal reels. Solved the problem by buying new heads from Teac, well after the warrenty expired.

greg

The isopropyl/water alcohol can be recreated to 99% pure. Just put it in the freezer, the water will freeze & you can pour off 99% pure isopropyl ;-)

taharka

Lexington, Kentucky U.S.A.

I've found that most automotive fuel deicer products are pure alcohol. A single bottle of Heet will last a long time around the shop....

jak

You might try Brasso polish - it contains a fine abrasive and may safely remove the corrosion if it's not too severe. Follow the directions on the can and apply with a Q-Tip. Allow it to dry thoroughly, then polish it off with a clean Q-tip. Keep repeating the process until the corrosion is gone. Remove any remaining Brasso residue with 91% or better Isopropyl Alcohol.

If that doesn't work and you are feeling brave, you could try something more abrasive like CD scratch remover liquid or maybe even automotive polishing compound. Just work slowly and carefully and be sure to remove any residue afterwards with the alcohol.

Has anybody separated the two like they do when making ice beer?

If you put deicer in, its not going to freeze until it gets really cold.

Using near 100% alcohol is good for applications, however many times the near 100% will quickly turn to near 100% water as the alcohol dries and absorbs water at the same time, so using near 100% alcohol doesn't usually happen unless its with a heat gun to dry it quickly. I used to clean tape heads with rubbing alcohol, I thought the mineral oil or other things in it helped lubricate the head, or other things clean with it.

greg

Oh I just thought about me using Rain-X deicing fluid. It contains Rain-X. Its the bright orange washer fluid. If you have used this stuff I don't see anybody going back to plain washer fluid.

I also used to use the washer fluid that went a lot colder than the regular fluid for the extra cold months. I imagine it used a purer alcohol but may just be another form?

greg

Just be aware that setting reversing heads azimuth isnt as simple as with single directoin heads.

NT

I transfer reel to reel tapes to CDR as a hobby, and side line. If you think cassettes shed oxide, imagine a 30 year old reel to reel tape stored ina garage, being played for the first time in 20 years. Even after a mild baking, they shed! I use naptha (lighter fluid) (very sparingly!) on a q-tip. You want just enough to wet the crud, not enough to run where you dont want it. Let it sit for a bit, and then with a clean swab, also lightly moistened in lighter fluid, start scrubbing it off. Several applications may be needed. I would avoid anything plastic, metal, or generally harder than your fingernail. I've also used a #2 pencil eraser to encourage the crud to be gone. After you get it off, then use alcohol to rinse the head, and remove the slightly oily film lighter fluid will leave. HTH!

Peace Deke

Thanks, I will try the lighter fluid first, then Brasso.

Follow-up question: In the middle of the head there's a kind of cross-hatching, which I guess is where the head reads the tape. Do I need to be particularly careful when cleaning this part of the head? In contrast, the sides of the head are shiny and smooth (if they were clean), and seem less susceptible to damage from cleaning. I'm still not clear on why the tape plays fine in one direction, and sounds muted in the other direction. Are there actually 2 areas on the tape head, one for each direction? If so I guess they would be positioned one on top of the other.

Many thanks to everyone who took the time to answer my original question. What a great forum, and great group of people, to share their expertise.

Bill

-- Farmer Bill[/i][/color]

I transfer reel to reel tapes to CDR as a hobby, and side line. If you think cassettes shed oxide, imagine a 30 year old reel to reel tape

stored ina garage, being played for the first time in 20 years. Even after

a mild baking, they shed! I use naptha (lighter fluid) (very sparingly!) on a q-tip. You want just enough to wet the crud, not enough to run where you dont want

it. Let it sit for a bit, and then with a clean swab, also lightly moistened in lighter fluid, start scrubbing it off. Several applications

may be needed. I would avoid anything plastic, metal, or generally harder than your fingernail. I've also used a #2 pencil eraser to encourage the crud to be

gone. After you get it off, then use alcohol to rinse the head, and remove the

slightly oily film lighter fluid will leave. HTH!

Peace Deke

-- Farmer Bill

Google for how heads work.

Try this after you get the heads as clean as you can. Take a sharpened #2 pencil and gently run the lead point vertically down the face of the head. If there is a groove that is noticeable, (you'll feel it when the pencil lead hits it) the head may be worn past the point of giving you good sound in both directions. Theres several different methods of auto reverse mechanics. Not knowing the make and model, its had to say why it works in one direction and is muffled in the other. And it could be out of alignment, but its more likely either dirty, or worn. Dont go tweaking anything untill you have exhausted all other posibilities. Get it clean first, then go from there. And forget about the brasso. Not good, IMHO.

Deke