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ARSCLIST  April 2013

ARSCLIST April 2013

Subject:

Re: tape chemistry/processing

From:

Shai Drori <[log in to unmask]>

Reply-To:

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

Date:

Sun, 7 Apr 2013 13:38:28 +0200

Content-Type:

text/plain

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Parts/Attachments

text/plain (151 lines)

I think it's 2.99 per tape.
Shai
בתאריך 07/04/13 11:32 AM, ציטוט Marie O'Connell:
> ummm, what is that from Roger Kulp?
>
>
> On Sun, Apr 7, 2013 at 10:43 AM, Roger Kulp <[log in to unmask]>wrote:
>
>>
>>
>> I could put together a group like that in a few months of buying at
>> Goodwill.The trouble is,most of them would be tapes of Trini Lopez or New
>> Christy Minstrels records,or some such.You will notice the seller does not
>> say what is actually on these tapes,as such the $2.99 per lot of 60 tapes
>> is about right.I don't see why for that money,it would even be worth the
>> trouble to list and ship them. Roger > Date: Sat, 6 Apr 2013 09:26:31
>> -0700> From: [log in to unmask]> Subject: Re: [ARSCLIST] tape
>> chemistry/processing> To: [log in to unmask]> > If we're looking
>> for how many different brands of reel to reel tape we're being sold in "the
>> good 'ole days", this eBay guy/girl seems to have bought them all......
>>
>> http://www.ebay.com/itm/60-Reel-Reel-Tapes-Buy-1-All-/390550178641?_trksid=p11021.m2364&_trkparms=aid%3D555001%26algo%3DPW.CURRENT%26ao%3D1%26asc%3D216%26meid%3D6768180066040736328%26pid%3D100084%26prg%3D1115%26rk%3D8%26sd%3D281088813854%26&ssPageName=ADME:B:SS:US:1120>
>>> --- On Fri, 4/5/13, Dan Nelson <[log in to unmask]> wrote:> > From:
>> Dan Nelson <[log in to unmask]>> Subject: Re: [ARSCLIST] tape
>> chemistry/processing> To: [log in to unmask]> Date: Friday, April
>> 5, 2013, 9:38 PM> > At DAK we got our binder and dry oxide from MagNox,
>> these were mixed in a drum mixer along with MEK as a thinning agent that
>> also improved adhesion to the base polyester (aka dupont mylar) film.> Mag
>> tape coating is similar to the first step in Offset printing. The oxide
>> (ink) is supplied to a roller and passes through a metering blade that
>> leaves a smooth thin layer of oxide on the roller that rotates against the
>> film base and transfers the oxide coating.  > Traveling through an oven
>> evaporates the solvent and begins to harden the coating, which next passes
>> through calendar rollers which smooths and compresses the oxide coating
>> under pressure and heat to finish hardening the coating.  > Two types of
>> calendar rollers were used with different tape surface textures. A Nylon
>> roller would leave a soft matte finish while a hard chrome roller would
>> give the oxide a highly polished sheen which looked nice but  would cause
>> increased odixe to tape head adhesion because of the lack of microscopic
>> air pockets in the oxide..... often to the point of squealing noise.> The
>> highly polished hard chrome surface was mostly used for video and high
>> speed instrumentation tape.> At DAK we coated on 6-8-12" web widths. Rotary
>> slitters converted the webs to 1/8" cassette and 1/4" reel stock into
>> master pancakes. > One step that could contribute to oxide flaking is the
>> calendaring processing where pressure and heat are critical to long term
>> adhesion.> The hard chrome finished surface of the oxide can contribute to
>> head/tape squeal due to surface adhesion. The hard chrome finish at one
>> time was promoted as providing few drop outs and more uniform output in
>> Master tape products when used at higher  tape speeds....  where did the
>> seconds end up ?  you guessed in the bargain boxed 3M and Ampex, which
>> accounts for the inconsistency of the bargain box stock. > Also the Melody
>> brand used reslit 1/2" computer stock that was returned to the mfgr for
>> credit toward new stock... it was part of a gov buy back program...  again
>>   nothing goes to waste, find a way to reuse it.> Even DAK  secured 1000's
>> of reels of computer and instrumentation tape to be reslit.> > d nelson
>> ward > > > Beautiful Music you will never forget, at;
>> http://www.americanbeautiful.podbean.com/> > > > > --- On Fri, 4/5/13,
>> Richard L. Hess <[log in to unmask]> wrote:> > > From: Richard L.
>> Hess <[log in to unmask]>> > Subject: Re: [ARSCLIST] Sticky
>> SHRED/tape chemistry> > To: [log in to unmask]> > Date: Friday,
>> April 5, 2013, 4:44 PM> > My understanding was that BF Goodrich> > Estane
>> was used widely as the binder.> > > > Dr. Bob Perry would not share any
>> Ampex secrets with me and> > said at the > > time they were still secrets
>> in his mind.> > > > PDF page 6 of my paper discusses this a bit more
>> formally> > than my > > previous post.> > > > This would be useful
>> information...> > > > Let's all rattle whatever cages we can.> > > >
>> Cheers,> > > > Richard> > > > On 2013-04-05 6:56 PM, Dan Nelson wrote:> > >
>> Back in the 80s i was working for DAK industries and we> > were coating our
>> own webs and slitting 1/8" and 1/4" stock.> > Before that i was familiar
>>   with Northridge magnetics> > who was making mastering quality 1/2" tape.>
>>>> In fact i set DAK up to buy the Northridge facility.> > > MagNox was a
>> prime supplier of  odixe and coating> > chemistry to the  industry as a
>> whole.> > > IM looking for my folder of spec sheets which i thought> > i
>> may have kept when the Air Quality Inspections in LA > > made it impossible
>> to use the  quantity solvents needed> > and DAK shut down the coating
>> plant.> > > Our next step was buying raw stock from Ampex here on> > the
>> West coast.> > > So any problems Ampex had in the 80s was passed onto> >
>> DAK labeled products.> > >> > > d nelson ward> > >> > > Beautiful Music you
>> will never forget, at; http://www.americanbeautiful.podbean.com/> > >> >
>>>>>>>>>>>> --- On Fri, 4/5/13, Tom Fine <[log in to unmask]>>
>>> wrote:> > >> > >> From: Tom Fine <[log in to unmask]>> > >>
>> Subject: Re: [ARSCLIST] Sticky SHRED> > >> To: [log in to unmask]>
>>>>> Date: Friday, April 5, 2013, 3:23 PM> > >> Richard, do any of these
>> researchers> > >> know the actual "recipes" for the tapes they are> >
>> studying?> > >> If not, is it possible to get that knowledge? Has> >
>> anyone> > >> interviewed in detail the tape manufacturers'> > chemists? It>
>>>>> sounds to me like we have a bunch of stabs in the> > dark and> > >>
>> theories. Are first-person details of actual> > recipes already> > >>
>> non-attainable?> > >>> > >> Also, I would think a modern manufacturer like
>> Mike> > Spitz or> > >> Zonal could shed some light, perhaps talking about>
>>> other> > >> companies recipes rather than their own?> > >>> > >> I really
>> think it's time to get down in the weeds> > with the> > >> chemistry, I
>> can't see why the whole process of> > sticky-shed> > >> is not
>> understandable, quantifiable and> > measurable???> > >>> > >> -- Tom Fine>
>>>>>>>>> ----- Original Message ----- From: "Richard L.> > Hess" <
>> [log in to unmask]>> > >> To: <[log in to unmask]>> > >>
>> Sent: Friday, April 05, 2013 6:02 PM> > >> Subject: Re: [ARSCLIST] Sticky
>> SHRED> > >>> > >>> > >>> Hi, Nigel,> > >>>> > >>> Thank you for this very
>> useful insight! This> > has been> > >> part of the mantra for a long time,
>> but it is> > wonderful to> > >> receive further confirmation.> > >>> We
>> cannot forget the "running changes" that> > Benoit> > >> Thiebaut
>> discovered specifically in U-Matic tapes,> > but I> > >> suspect that
>> process "improvements" were common as> > tapes> > >> were running and if
>> this 60-70 % factor is involved> > it> > >> doesn't even have to be a
>> process improvement.> > >>> Cheers,> > >>>> > >>> Richard> > >>>> > >>> On
>> 2013-04-05 4:53 PM, Nigel Champion wrote:> > >>>> At last year's IASA
>> conference in New> > Delhi,> > >> Dietrich Schueller presented information
>> gleaned> > from> > >> discussions with retired employees of the major> >
>> German tape> > >> manufacturers, BASF & AGFA. Some expressed the> >
>> opinion> > >> that subtleties in the manufacturing procedures had> > more>
>>>>> influence on the finished quality of magnetic tape> > than the> > >>
>> actual chemical mix by a factor of 60% or 70%.> > >>>> I infer from this
>> that, even if one tape> > has> > >> exactly the same chemical constituents
>> as another,> > a small> > >> variation in one step of the manufacturing> >
>> processes can> > >> result in pronounced differences in measures of> >
>> quality such> > >> as performance, stability and/or longevity. > > Such a>
>>>>> situation makes comparisons very difficult at this> > late> > >> stage
>> for those considering chemical analysis of> > >> constituents or assessing
>> differing degradation> > under> > >> controlled climatic conditions as
>> suggested> > recently on this> > >> list for sticky-shed.  It would also
>> explain> > the> > >> differing experiences of many on this list with the> >
>> "same"> > >> tape.> > >>>> Nigel> > >>>>> > >>>>
>> ________________________________________> > >>>> From: Association for
>> Recorded Sound> > Discussion> > >> List [[log in to unmask]]> > >>
>> on behalf of Tom Fine [[log in to unmask]]> > >>>> Sent: 06
>> April 2013 07:23> > >>>> To: [log in to unmask]> > >>>> Subject:
>> Re: [ARSCLIST] Sticky SHRED> > >>>>> > >>>> I think Dennis is bringing up a
>> really> > important> > >> point. Sarah and Richard, do you have any
>> contacts> > >>>> with original tape manufacturer chemists,> > people> > >>
>> who were familiar with the "brew" of the tapes?> > >>>> Before these people
>> die, it's important to> > get> > >> information from them about what
>> chemicals were> > used> > >>>> in the binders. There's no "state secret"> >
>> anymore> > >> -- all of those tape manufacturers are out of> > >>>>
>> business now (and I'm afraid, given how> > things> > >> work, that
>> corporate records detailing the "brew"> > are> > >>>> probably lost to
>> time).> > >>>> <SNIP>> > >>>>> > >>>> -- Tom Fine> > >>>>> > >>> -- 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.> > > > -- > > 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.> >
>>

-- 
בברכה,
שי דרורי
מומחה לשימור והמרה של אודיו וידאו וסרטים 8-35 ממ.

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