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Goran Finnberg's claims got me wondering what was his baseline of audio 
distortion. Presumably with  a tape with significant binder problems, the HF 
distortion would not be measureable without having first baked the tape, 
hence hard to know how one could document the change in distortion after 
baking. Perhaps he used a tape which had already been adequately baked and 
so could be played without issues and distortion measurements made. Then 
perhaps the same tape was rebaked, not to increase playability, but to 
measure any changes in the signal distortion after that second baking. It 
would be interesting to read more details of the test procedure and the 
actual distortion increases that he measured.

Tim Gillett
Perth, Western Australia.


----- Original Message ----- 
From: "Corey Bailey" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, October 02, 2017 1:40 PM
Subject: Re: [ARSCLIST] Problematic reel (bleedthrough, shedding, mold) - 
basic advice?


> Hi Eli,
>
> To address your question: The tape would be baked when dry. All 
> contaminants (Mold, moisture, etc.) will have been removed and any leaders 
> replaced that need it. For me, baking an analog (or digital) tape is the 
> last resort. Baking has consequences and not enough research (IMHO) has 
> been done as to what those consequences are. In 2015, Goran Finnberg 
> posted to the ARSC list that he had measured an increase in AM distortion 
> with the first baking of audio tape and the AM distortion increased with 
> subsequent baking. This would possibly explain the changes in overall 
> fidelity that I and others have noticed as the result of baking. However, 
> there has been no follow-up by Groan so, at this point, I would have to 
> consider his comments as anecdotal. What I do for PVC based tapes, that 
> exhibit SSS, is to generously apply Tape Last from The Last Factory. I 
> have found Tape Last to be about 95% effective when it comes to making 
> problem tapes playable. If, after treatment, the tape is still cranky and 
> won't behave, it gets baked. I have been assured by The Last Factory that 
> baking a tape which has been treated will have no consequences and my 
> experience supports that claim. Last Factory has also said that treating 
> an analog tape with Tape Last will enhance the shelf life but I personally 
> have no evidence to support their claim. Tape Last is expensive and the 
> process is time consuming so institutions with large holdings will bake 
> first and ask questions later. It's simply a matter of economics.
>
> Disclaimer:
>
> I have no connection with The Last Factory and receive no compensation, in 
> any form, from them.
>
> Cheers!
>
> Corey
>
> Corey Bailey Audio Engineering
> www.baileyzone.net
>
> On 10/1/2017 11:40 AM, Eli Bildirici wrote:
>> <SNIP>
>> Also - to clarify, should I soak, wait for it to dry a bit, and then 
>> attempt to bake? I'm also not quite sure I understood re how 'removing 
>> the grille' helps. Isn't the issue that the central hole is to wide? It 
>> looks like we'd have to somehow modify one of the trays in order to get a 
>> 7"er on there, right?
>>
>> September 28 2017 11:34 AM, "Richard L. Hess" <[log in to unmask]> 
>> wrote:
>>> When I do moldy tapes, I use a NIOSH dual-cartridge respirator.
>>>
>>> Don't risk your health.
>>>
>>> On 2017-09-27 11:29 PM, Corey Bailey wrote:
>>>
>>>> Hi Eli,
>>>> Sorry, I didn't see your question about the "Soaking". I had a tape > 
>>>> similar to your problem tape
>>>> and here's what I did: I used a round film > can and (literally) 
>>>> submerged the 7" reel of tape in
>>>> medical alcoholfor > about an hour. You can submerge the tape for 
>>>> longer if you think it > needs it
>>>> because (IMHO) pure alcohol does not harm PVC base audio tape. > Others 
>>>> may differ. After the
>>>> "Soaking", I unwound the tape, slowly, by > hand, while wiping with 
>>>> pellon. Much the same as you
>>>> describe except I > use a modified 8MM film editor for this task. I had 
>>>> to replace every > leader
>>>> on this particular tape and there were lots of them. Mold is > serious 
>>>> business. Much of it is
>>>> microscopic and the spores get > everywhere. If you are indoors, you 
>>>> need a "clean room" that is
>>>> isolated > from everything else. I set up outside, away from anything 
>>>> that may be > subject to mold
>>>> contamination. Only after I was confident that I had > conquered the 
>>>> mold contamination, did I
>>>> consider baking the tape. In > this case, the tape did not need to be 
>>>> baked. The tape (Again, IMHO)
>>>> was > Scotch 206 and played fine after restoration*. * Restoration 
>>>> included > lubricating the
>>>> entire tape...Another topic for another time.
>>>> Corey
>>>> Corey Bailey Audio Engineering
>>>> www.baileyzone.net
>>>> On 9/27/2017 1:27 PM, Eli Bildirici wrote:
>>>>> Shai wrote:
>>>>>
>>>>> "The bleed through could also be print through. It actually doesn't >> 
>>>>> look as
>>>>> bad as I thought. I would start with a low temp bake (about 40 >> 
>>>>> Celsius) for
>>>>> 24-48 hours.Next I would try to unspool and clean a short length of >> 
>>>>> tape to
>>>>> see if any flaking occurs. If not I would clean the rest of the tape 
>>>>> and
>>>>> try to play. If it still give trouble I would rebake for antoher 24 
>>>>> hours
>>>>> at 55 Celsius."
>>>>>
>>>>> Thanks. What we've had to do however, as nearly all of our content >> 
>>>>> left to digitize and
>>>>> catalogue
>>>>> are on 7" reels, is first transfer them onto a 10" one, as that's what 
>>>>>  >> fits in our dehydrator:
>>>>>
>>>>> https://imgur.com/sCyrUqK
>>>>>
>>>>> I'm realizing based on these comments though that this is far from >> 
>>>>> ideal (and follows logically,
>>>>> at that), so if anybody has advice as to >> particular models of 
>>>>> dehydrators that can accommodate
>>>>> reels of this >> size, I'm all ears.
>>>>>
>>>>> Corey - can you elaborate on the 'soaking' process? What we've been >> 
>>>>> doing until now is using a
>>>>> dedicated R2R solely for cleaning, playing >> through a tape while 
>>>>> holding a bit of Pellon with
>>>>> some 99% isopropyl >> alcohol against it as it spools. Soaking it 
>>>>> without unspooling is of >>
>>>>> course very different - how long do you think? How deep? Should it go 
>>>>>  >> straight from having been
>>>>> soaked (ideally) into the dehydrator?
>>>>>
>>>>> Would you guys propose checking the tape whilst it's being baked every 
>>>>>  >> 24 hours?
>>>>>
>>>>> Increasingly, many of our reels left to process appear to have a bunch 
>>>>>  >> of different, unrelated
>>>>> segments strewn together, sometimes in the >> wrong direction and 
>>>>> rarely with any kind of
>>>>> indication as to what's on >> there. Often if not always, if leader is 
>>>>> used to separate the
>>>>> segments >> at all, it is paper. In case there is no mold, but the 
>>>>> tapes are >> shedding, should
>>>>>
>>>>> I looked at Richard Hess's site yesterday and found this reference: >>
>>>>> http://richardhess.com/notes/formats/magnetic-media/magnetic-tapes/analog-audio/degrading-tapes 
>>>>>  >>
>>>>> I don't think there's a way to identify tape stock by sight though, so 
>>>>>  >> it looks like this
>>>>> doesn't help me much. I've been going through the >> Specs site, 
>>>>> meanwhile. Among the more
>>>>> interesting things is the >> implication that this white residue I'm 
>>>>> seeing...isn't actually mold?
>>>>>>> But instead may "indicate breakdown of various chemical components":
>>>>> http://www.specsbros.com/white-paper-basic-inspection-techniques-to-sample-the-condition-of-magnetic
>>>>> tape.html >>
>>>>>
>>>>> I'm not sure what, if any, ramifications this could have.
>>>>>
>>>>> E
>>>>>
>>>>> September 27 2017 2:53 PM, "Corey Bailey" <[log in to unmask]> >> 
>>>>> wrote:
>>>> Hi Eli,
>>>>
>>>> You have a host of problems with this reel of tape (preaching to the 
>>>>  >>> choir here): Mold,
>>>> Shedding
>>>> which may require some baking, and segments separated by paper >>> 
>>>> leader. Paper leader is not bad
>>>> by
>>>> itself but, in this case, it's adding to the problem because of mold 
>>>>  >>> and moisture absorption.
>>>>
>>>> 1) Address the mold. Baking a moldy tape will contaminate your oven. 
>>>>  >>> Avoid (if you can) any
>>>> water
>>>> based mold killing products. Pure alcohol work well as a first or >>> 
>>>> second application. Soaking
>>>> the
>>>> tape with alcohol may reduce the sticky layer problem to the point >>> 
>>>> that it can be carefully
>>>> unwound
>>>> to move on to step 2.
>>>>
>>>> 2) Replace the paper leader with plastic leader. I've also used blank 
>>>>  >>> Polyester tape (reversed)
>>>> as
>>>> leader. Then, continue with mold removal because you want to remove >>> 
>>>> ALL of the mold.
>>>>
>>>> 3) Bake the tape if you think it is safe to do so. Bake looow (Temp) 
>>>>  >>> and sloow: Less than 49C
>>>> (120F) for as long as it takes. 24 to 48 hours would not be uncommon. 
>>>>  >>> I would suggest using a
>>>> dehydrator for this particular application or, any unit that you can 
>>>>  >>> safely dispose of because
>>>> contamination may be unavoidable, rendering the baking device >>> 
>>>> unusable for anything else.
>>>>
>>>> Check with Peter Brothers to see if Specs Bros. may have some advice: 
>>>>  >>> http://www.specsbros.com
>>>>
>>>> You may have to decide which is more important: Saving the tape or >>> 
>>>> saving the equipment.
>>>> Corporate
>>>> America, in my experience, would decide that the process is too >>> 
>>>> expensive and chuck the tape.
>>>>
>>>> Advise is free so, contact me off-list if you like.
>>>>
>>>> Sorry,
>>>>
>>>> Corey
>>>>
>>>> Corey Bailey Audio Engineering
>>>> www.baileyzone.net
>>>>
>>>> On 9/26/2017 1:56 PM, Eli Bildirici wrote:
>>>>
>>>> We all just double-checked and it looks like polyester rather than >>>> 
>>>> acetate. My guess is the
>>>> angle
>>>> of my phone and the way the sunlight was hitting the tape made it >>>> 
>>>> look wrong. Do you have any
>>>> advice re baking?
>>>>
>>>> September 26 2017 4:27 PM, "John Chester" <[log in to unmask]> wrote:
>>>> On 9/26/17 4:10 PM, Ted Kendall wrote:
>>>> If you are getting what I think you mean by bleedthrough, bits of > 
>>>>  >>>> oxide have already lifted
>>>> and
>>>> stuck to the back of adjacent turns. If > you have played it, it's >>>> 
>>>> probably too late to do
>>>> much,
>>>> but you could > start by baking and see what can be salvaged.
>>>> The loose end of the tape which I see in the photos is red oxide with 
>>>>  >>> no backcoating. Tapes
>>>> without backcoating rarely need to be baked. If any of the tape on >>> 
>>>> this reel is acetate base,
>>>> it
>>>> should absolutely not be baked. To check for acetate base, hold the >>> 
>>>> reel up to a light -- if
>>>> you
>>>> can see light through the tape pack, it's acetate.
>>>>
>>>> The nightmare scenario is a mixed reel that's got sticky-shed tape on 
>>>>  >>> the outside, and acetate
>>>> tape
>>>> further into the reel. In that case, you pretty much have to decide >>> 
>>>> which you will save,
>>>> because
>>>> you probably can't save both. Baking will ruin the acetate, and >>> 
>>>> unspooling the sticky-shed tape
>>>> without baking may leave large chunks of oxide stuck to the 
>>>> backcoating.
>>>>
>>>> -- John Chester
>>>>> Eli Bildirici
>>>>> (347) 837-8337
>>>> -- 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.
>> Eli Bildirici
>> (347) 837-8337 


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