"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:
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":
I'm not sure what, if any, ramifications this could have.
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.
> Corey Bailey Audio Engineering
> 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