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ARSCLIST  March 2015

ARSCLIST March 2015

Subject:

Re: Distressing data point for upcoming ARSC tape playback workshop

From:

"Richard L. Hess" <[log in to unmask]>

Reply-To:

Association for Recorded Sound Discussion List <[log in to unmask]>

Date:

Mon, 2 Mar 2015 11:58:27 -0500

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (336 lines)

Hi, Corey,

What an informative post. Thanks. Thanks also for the credit, but I have 
to credit Friedrich Engel.

As to Naptha and Hexane: they are very similar. As you are undoubtedly 
familiar from grade-school science, petroleum is segregated (fractioned) 
by weight in "fractioning towers" (or at least that's how I recall it 
from the 1950s/1960s). The different length molecules have different 
weights. This is just another form of distillation, I think.

This Wikipedia article has a good description (it appears accurate or at 
least plausible) about the different types of naphtha.

The brand of choice for me has been Ronsonol but now that Zippo has 
bought them, they claim "no more naphtha" but, considering the use of 
the word, I think it's as much a marketing ploy as a chemical analysis.

Here is a pre-Zippo data sheet:

http://www.ronson.com/en/Safety%20Data%20Sheet%20Ronsonol%20Lighter%20Fluid%20Mar02.pdf

Chemical composition : blend of aliphatic hydrocarbons

Name 			CAS No 		Content %
Xylene 			1330 – 20 – 7 	1 – 5
Propylbenzene 		98 – 82 – 8 	0 – 1
n-heptane 		142 – 82 – 5 	10 – 30
mesitylene 		108 – 67 – 8 	0 – 1
1,2,4-trimethylbenzene 	95 – 63 – 6 	0 – 1
n-hexane 		110 – 54 – 3 	1 - 5

The Pennsylvania Right to Know law statement on the last page of this
http://secure.cooperbooth.com/datasheets/160606.pdf
is also of interest.

This article more clearly states that naphtha is an intermediate 
distillation product.
http://www.newworldencyclopedia.org/entry/Naphtha

"Naphtha is known by various names, depending on its source, 
composition, uses, and manufacturing company. Some names include 
ligroin, VM&P Naphtha (Varnish Makers and Painter's Naphtha,[1] Benzin, 
petroleum naphtha, petroleum spirits, and naphtha ASTM. Another name is 
shellite (Australia)—also known as white gas (North America), white 
spirit, or Coleman fuel—which is a white liquid with a hydrocarbon odor. 
Given its high flammability and low flashpoint (less than -30 °C), it is 
used in many low-pressure camping stoves. Ronsonol is a brand name used 
in North America and is marketed as a refill fluid for cigarette lighters."

...

"Naphtha is obtained in petroleum refineries as one of the intermediate 
products from the distillation of crude oil. It is a liquid intermediate 
between the light gases in the crude oil and the heavier liquid 
kerosene. Naphthas are volatile, flammable and have a specific gravity 
of about 0.7. The generic name naphtha describes a range of different 
refinery intermediate products used in different applications. To 
further complicate the matter, similar naphtha types are often referred 
to by different names."

So, I think it is convenient if you think of a huge column (let's say 50 
feet tall) of petroleum products, with very light ones on top and sludge 
on the bottom. Then perhaps Naphtha is considered 10 feet of that column 
in the upper middle. Hexane would maybe be 6 inches of the column.

I'm making this up, but this mental model helps me understand the 
differences of what we are talking about. I, too, have had Hexane 
recommended to me. Serious chemists use hexane, shop mechanics use 
naphtha <smile>.

Personally, I buy Ronsonol and I think it's still available here in Canada.

As to cleaning moldy tapes, I use a dilute chlorine bleach solution as 
it is my understanding that chlorine will really do in the mold. Instead 
of the hand-winding arrangement, I use an older Sony APR_5000 which I 
keep in the garage for that purpose.

I use a NIOSH two-cartridge respirator and gloves.

Cheers,

Richard


On 2015-03-02 4:31 AM, Corey Bailey wrote:
> Hi Tom,
> "Different coasts, similar methods"
>
> I too use alcohol for dealing with mold on tapes and vinyl records.
> First of all, I use the same safety precautions that you propose. I use
> the highest percentage alcohol I can find, generally 99% or medical
> alcohol (if I can buy it) so that the least amount of water is involved
> in the cleaning process. Weather permitting, (usually the case here on
> So. Cal.) I work outside. I will start by drenching the tape with
> alcohol, even if it has paper leaders. I then use an 8MM movie editor
> attached to a 2' X 4' piece of counter top to provide a work surface to
> transfer the tape from the mold infested reel to a clean one. During
> this process. I wind the tape through a piece of pelon, drenched with
> alcohol, so that the tape gets wiped as it gets wound to the clean reel.
> I've had tapes that take two or more passes through pelon wipes to come
> completely clean. I've learned from experience to judge when this will
> be needed and use some interim reels for winding. If paper leaders are
> involved, they will get replaced. This is where the work space comes in
> handy (otherwise, it's a PITA to store). If I have to use more than one
> take-up reel during the process, I will soak the reels in alcohol (you
> can use the cheaper stuff for this) for an hour or so to clean them.
> White vinegar will also work for the cleanup chores.
>
> Removing splice tape:
> I have found that sharpening the wooden handle of a medical type Q-Tip
> to a chisel shape works well to lift the tape just enough to get a grip
> with your fingernails. I'll have to try Tom's method of doing the same
> with a chop stick. Likewise, I have found naphtha to be the most
> effective for goo removal. Hexane works well but is more expensive and
> seems toxic to me.
>
> I have taken the wood handle of a cheap artist paint brush, removed the
> brush, and fashioned the wood handle into a screw driver shape. This is
> used to apply and remove Teflon tape to the record and erase heads not
> used for playback because I haven't removed them from the tape path.
>
> Playing acetate tapes:
> If I need to add pressure at the play head, I use an artists paint
> brush, held in place by an "electronic helper" alligator clip stand. I
> have trimmed the brush to make the bristle area a little stiffer.
> Sometimes, positioning the brush on the incoming side of the head gives
> a better wrap. Using Marie O'Connell's method of drenching the tape in
> alcohol while playing can help. That process is a mess though. Marie has
> modified her equipment to use the alcohol playback process.
>
> Humidifying acetate tapes:
> I have successfully used the method mentioned by Eric Jacobs. I got it
> from Richard Hess. However, before doing that, I will try the simple
> method of placing a dampened cotton ball in each corner of a cardboard
> tape box with the tape for about 24 hours then check it to see if there
> is any progress. I will usually try this twice before moving on to the
> method mentioned by Eric & Richard.
>
> Other thoughts:
> I'm not convinced of any connection between the long term conditions
> affecting acetate audio tape and magnetic film other than VS and the
> conditions that cause it and the methods for dealing with it are well
> documented. The two products share similarities in basic fabrication but
> magnetic film has a 5 mil base thickness and a much thicker oxide layer
> that, most likely, makes the big difference.........All anecdotal.
>
> Speaking of anecdotal, it is my considered opinion that storage
> conditions over time are the major factor affecting the condition and
> ultimate playability of audio tape and magnetic film.
>
> I personally find it incredible that with the varied amount of audio
> tape that has been produced and used over the years that more scientific
> studies haven't been conducted to address the various conditions that
> befall it. Although we have AMPEX to thank for providing the archival
> world with a method of retrieving the audio from tapes suffering from
> SS, no other manufacturer (to my knowledge) has come forward to lend a
> hand.
>
> And, speaking of SS, we are now finding digital audio tape affected by
> SS. Both consumer and professional products! A situation that, when
> compared to analog audio tape is supposed to be apples and
> oranges.....What's up with that?
>
> My $0.02
>
> Corey
> Corey Bailey Audio Engineering
> www.baileyzone.net
>
>
> On 3/1/2015 3:17 PM, Tom Fine wrote:
>> Hi Eric:
>>
>> I have encountered a few moldy tapes over the years. I also watched
>> (over a few years, because it was fascinating) mold literally eat away
>> a couple reels of acetate tape in a damp part of my parents basement.
>> This was really interesting because, in the end, all that was left was
>> a pile of brown powder in and around an empty metal reel. The boxes
>> completely decomposed later. I would say this process took 10 years,
>> but this was decades ago and who knows how damp the tapes had been
>> before I noticed the mold and kept them in place to watch the decay
>> over time.
>>
>> In the times I have been given moldy reels for transfer, I gathered
>> this wisdom to share:
>>
>> 1. ALWAYS WEAR A MOLD-BLOCKING MASK. You never know exactly what kind
>> of mold is on a moldy tape and how it will react with your respiratory
>> system. I'm very allergic to mold, so I know right away when it's
>> present because I get sneezy/coughy and my eyes get watery. WEAR
>> GLOVES, TOO. And change clothes and wash up when you're done
>> mitigating the mold.
>>
>> 2. In my experiece, isopropynol alcohol will remove the molds I've
>> encountered on reel tapes. I use it liberally on the mold spots. It
>> has not damaged the tapes if I wipe it and the dislodged mold off
>> quickly. I wonder if Naptha will do the trick, too? Have not tried it.
>> You'd think that Naptha would be deadly to mold.
>>
>> 3. If mold is well established on acetate tape, good luck. It's
>> probably eaten away some of the acetate, and it's unlikely that the
>> tape will play correctly. If you're lucky and it's just on the edge,
>> isopropynol will work but now I'm thinking Naptha is better for the
>> tape. I'm not a chemist so I might be all wrong on that!
>>
>> 4. throw out moldy plastic reels and moldy cardboard boxes. Re-package
>> the cleaned tape on clean reels in clean boxes.
>>
>> 5. thoroughly clean the heads and tape path after transferring a moldy
>> tape. I'm sure spores fall off and get stuck on things.
>>
>> 6. if you accept for a transfer a box of moldy tapes, be fully mindful
>> of EVERYTHING in the box. Where there's mold there's liable to be
>> mice. Hantavirus is nothing to fool with. It's not just out west, it's
>> turned up in lean-tos and other places all over the northeast. Mice
>> carry all kinds of other nasty diseases. They are filthy vermin. Rats
>> and other rodents are just as bad and are just as likely to be around
>> an old box of tapes that got moldy.
>>
>> By the way, I had good luck cleaning mold off LP records with
>> isopropynol, too. I cleaned the mold and connect chunks of sleeve
>> material that way, then ran them through my VPI machine and they
>> turned out pretty much un-scathed. This was a pile of classical and
>> jazz LPs I saw dumped by the road after Sandy. DO NOT use isopropynol
>> on shellac records because it will melt them.
>>
>> -- Tom Fine
>>
>> ----- Original Message ----- From: "Eric Jacobs"
>> <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Sunday, March 01, 2015 5:28 PM
>> Subject: Re: [ARSCLIST] Distressing data point for upcoming ARSC tape
>> playback workshop
>>
>>
>>> Hi Tom,
>>>
>>> Thank you for starting this excellent thread.
>>>
>>> I wanted to chime in with two brief points that I think haven¹t been
>>> covered yet:
>>>
>>> 1.  When encountering a moldy tape, you need to weigh the cost of mold
>>>    removal against the risk of VS when segregating and storing moldy
>>>    tapes in sealed bags (with or without a desiccant like silica gel).
>>>    As noted by others, VS seems to be a function of storage temperature,
>>>    therefore moldy tapes that are stored and sealed should be stored in
>>>    a ³cold² environment to minimize the risk of VS.  If you can afford
>>>    to do it, it is still best to remove the mold.
>>>
>>>>
>>>> Another distressing datapoint ... This is the second batch of late
>>>> 1950s
>>>> Audiotape acetate-backed
>>>> tape I'm dealing with that has become very brittle, like most of the
>>>> plasticity has dried out of the
>>>> backing. I suspect this is made worse by over-dry storage conditions
>>>> intended to somehow "prevent"
>>>> or "mitigate" sticky-shed in later tapes (and remember that there is no
>>>> proof that dry storage does
>>>> either). I wish some scientists would do some chemistry on acetate
>>>> tapes
>>>> and come up with better
>>>> storage recommendations. There are millions of acetate tapes and films
>>>> being stored under the same
>>>> "keep it super-dry and cold" mandates that are imposed on polyester
>>>> media
>>>
>>>
>>> 2.  I have had reasonable luck ³de-brittling² acetate tapes by placing
>>> them
>>>    in a cool humid environment.  For example, I use a clear plastic
>>>    container and place a tray of distilled water on the bottom, and then
>>>    suspend the brittle reels above the tray.  The container has openings
>>> that
>>>    I can adjust to roughly control RH - I target a 60-70% RH.  I do this
>>> in
>>>    a room that is in the low-60s F and dark.  I monitor and check the
>>> tapes
>>>    daily - I worry about activating any potential mold spores. The tapes
>>> will
>>>    slowly become more pliable over the course of 1-4 weeks (every
>>> tape is
>>>    different, some do not respond).  Once reasonably pliable, I remove
>>> the
>>>    tapes and let them acclimate to the RH of the studio for about a
>>> week.
>>>
>>>    Certainly not a production method because it takes time and
>>> monitoring,
>>>    but it generally helps.
>>>
>>>    I do not humidify tapes that have known mold exposure.
>>>
>>>
>>>    From a chemistry point of view, this doesn¹t seem like it should
>>> work,
>>>    so I¹m not sure what mechanisms are at play.
>>>
>>>    The suggestion by John Schroth of using camphor is very interesting,
>>>    and I may try this - although I need to find the right container.
>>>
>>>    Would love to hear if anyone else has tried ³humidifying² acetate
>>>    tapes - intentionally or otherwise.
>>>
>>>
>>> ~ Eric
>>>
>>>
>>> _________________________
>>>
>>> Eric Jacobs
>>> Principal
>>> The Audio Archive, Inc.
>>> 1325 Howard Ave, #906
>>> Burlingame, CA 94010
>>>
>>> tel: 408-221-2128
>>> [log in to unmask]
>>> http://www.theaudioarchive.com
>>>
>>> Disc and Tape Audio Transfer Services and Preservation Consulting
>>>
>>> Please consider the environment before printing this email.
>>>
>>>
>>
>
-- 
Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada                             647 479 2800
http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.

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