28 Apr
2020
28 Apr
'20
3:56 a.m.
28 Apr
28 Apr
3:59 a.m.
On 4/28/20 3:56 AM, Al Kossow via cctalk wrote:
https://listserv.loc.gov/cgi-bin/wa?A2=ARSCLIST;d144d59c.2004
11:47 a.m.
I'm a bit surprised that this is even a "thing" in the audio business.
Restorers have been baking audio tapes for a long time.
One thing not discussed (maybe it doesn't occur in audio) is that there
can be issues in binder formulation, at least in digital tapes. In
particular, 3M tapes, most notably Scotch 701 and 777 formulations, have
an issue where the binder "liquefies" under motion and solidifies when
tape motion slows or ceases. So, you may be running a tape through a
drive just fine and then suddenly, everything freezes up as the tape
becomes firmly "glued" to the heads or other objects in the tape path,
usually with a loud squeal.
In the current batch of 60 tapes from the late 60s-mid 70s, every single
3M tape exhibited this behavior. It didn't matter if they'd been baked
or not. There was a note of this on Ed Thelen's site where someone had
encountered this and given up.
Isopropanol does not clean the sticky deposits from equipment--you must
use a stronger solvent. Acetone, Perc or MEK generally does the trick.
Rather than try to clean the gunk off the tape, which is probably a
fool's errand, I coat the tape with cyclomethicone, using a felt
applicator in my cleaning machine--it doesn't take much to create a
slippery film on the tape surface, perhaps 10 ml will do a 2400' tape.
Cylcomethicone is non-toxic and relatively inert--and is somewhat
volatile, so that it evaporates in a couple of hours, leaving the tape
as it was. Very slippery stuff, so don't spill it on the floor! It
does not appear to have a solvent effect on the binder, as nearly as I
can tell. It also doesn't appear to bother the equipment either.
I've achieved 100% success using this method.
I think it's interesting that tape quality tends to better the older the
tape. Audio Devices, Ampex and IBM Series 500 tapes tend to survive the
best. Memorex seems to get worse, the younger it is. (e.g. MRX III
tends to behave better than MRX V).
For whatever it's worth,
Chuck
1:14 p.m.
On Apr 28, 2020, at 11:47 AM, Chuck Guzis via cctech wrote:
Rather than try to clean the gunk off the tape, which
is probably a
fool's errand, I coat the tape with cyclomethicone
Just as a word of caution, I've had at least one catastrophic outcome trying this with
a QIC tape. Use too much (when "not enough" isn't cutting it), the belt
can't do its job, and what I ended up with was a big knot.
ok
bear.
--
until further notice
9:33 p.m.
On 4/28/20 1:14 PM, r.stricklin via cctalk wrote:
On Apr 28, 2020, at 11:47 AM, Chuck Guzis via cctech wrote:
Never tried it on QIC tapes; only 1/2" open-reel. I despise QIC-family
(and by extension) Travan tapes. Lots of frustration and heartache.
--Chuck
Rather than try to clean the gunk off the tape,
which is probably a
fool's errand, I coat the tape with cyclomethicone
Just as a word of caution, I've had at least one catastrophic outcome trying this
with a QIC tape. Use too much (when "not enough" isn't cutting it), the belt
can't do its job, and what I ended up with was a big knot.
29 Apr
29 Apr
10:47 a.m.
New subject: 1/2" tape shipping; was: tape baking
This had nothing to do with tape baking, but it's something nonetheless
that I think is important regarding tape handling.
After a couple of years of struggling with a customer to get them to
package tapes correctly, I've finally succeeded. Here's what I
recommend for ordinary 10.5" reels of tapes:
Get some double-walled cardboard "book boxes" from your supplier. These
are 1 cubic foot, 12"x12"x12" and are made for moving books. Your local
U-Haul store probably stocks these for a reasonable price, as do most
office supply stores.
Using some large-bubble (half-inch or more) 12" wrap, make sure that
there's a layer at the bottom of the box and that all sides are covered.
You can usually do this with two 40" long strips of wrap, forming a
"U" shape.
Place no more than 11 tapes in a box surrounded by the wrap; fold the
top of the wrap over the stack of reels and add wrap as needed to fill
the box. Seal the box securely on both top and bottom. Attach any
warning labels as needed.
A box with 11 tapes will weigh about 28 pounds; one with 10 will come in
at 25 lbs.
The thing to note is that shipping tapes in large boxes of 40-50 tapes
is likely to result in damage to reels. Reels can be repaired, but it's
an avoidable nuisance.
Using the "book box" method, we haven't lost a single tape to damage.
25 lbs. seems to be a weight and size that Fedex and UPS handlers are
comfortable with.
When working with tapes, plastic "milk crates" normally used for office
hanging folders are a perfect size to separate work in batches of 10
reels or so. One crate = one "book box".
If you require containers for 10.5" tape reels, a plastic film can made
for an 800' reel of 16mm film is perfectly sized. I get mine from Larry
Urbanski (https://www.urbanskifilm.com/).
For what it's worth,
Chuck
28 Apr
28 Apr
3:08 p.m.
On 4/28/20 11:47 AM, Chuck Guzis via cctalk wrote:
For whatever it's worth
Magnetic tape recovery people live in silos
I doubt anyone at LoC has ever even heard of you or me, or that they will ever
see the years of discussions we've had on this subject. I wonder if
they he even talked to the LoC teams doing digital recovery.
The only thing of value I saw in the discussion were some theories of what
is happening chemically to the binder with application of heat.
3:37 p.m.
On 4/28/20 11:47 AM, Chuck Guzis via cctalk wrote:
I'm a bit surprised that this is even a
"thing" in the audio business.
Restorers have been baking audio tapes for a long time.
That is acknowledged in the slides, isn't it?
"Thermal Baking: A popular, poorly understood remedy"
"Most common remediation (successfully used for decades)"
"No consistent baking procedures - to this day audio tape users argue
about about why it works."
Isopropanol does not clean the sticky deposits from
equipment--you must
use a stronger solvent. Acetone, Perc or MEK generally does the trick.
I am trying to read a bunch of late 80s QIC-24 tapes (Sun/Computervision
install media). In addition to the normal QIC band problem, I am seeing
problems with the tape sticking on the metal posts that the tape goes
around to change direction towards the reels. Should I try wiping the
posts with acetone or wiping the tape with cyclomethicone? Should I be
baking the tapes? If so, what is a safe way to bake QIC cartridges?
alan
3:44 p.m.
On 4/28/20 3:37 PM, Alan Perry via cctalk wrote:
wiping the posts with acetone or wiping the tape with
cyclomethicone? Should I be baking the tapes? If so, what is a safe way to bake QIC
cartridges?
I bake the carts with the bands removed and the covers off in a food dehydrator
I also wrap the posts with lint-free cloth and use a rubber glue like fabric adhesive I
found in the crafts section of wallmart
Obviously, I re-use the bases until the cloth becomes fouled
QIC tape is thin, I wouldn't recommend using any liquid on it, even as a lubricant. It
is very easy to wipe the binder off
The brand of drive you use is really important. the direct drive tanbergs work the best
I went through about 100 computervision sun3 era carts last year. They weren't
horrible, using reused DC150 belts
I didn't get the images uploaded before I got locked out of my lab.
29 Apr
29 Apr
10:01 p.m.
I see the tape sticking to posts syndrome in my limited experience with HP QIC tapes also
(DC100 / DC2000). The best I have come up with is wipe the posts with isopropanol. But I
had not thought of lubricating them for a 1 time read, interesting idea. Or replacing the
posts with ones machined from Teflon or Delrin?
Marc
On Apr 28, 2020, at 3:37 PM, Alan Perry via cctalk
<cctalk at classiccmp.org> wrote:
?
On 4/28/20 11:47 AM, Chuck Guzis via cctalk
wrote:
I'm a bit surprised that this is even a "thing" in the audio business.
Restorers have been baking audio tapes for a long time.
That is acknowledged in the slides, isn't it?
"Thermal Baking: A popular, poorly understood remedy"
"Most common remediation (successfully used for decades)"
"No consistent baking procedures - to this day audio tape users argue about about
why it works."
Isopropanol does not clean the sticky deposits
from equipment--you must
use a stronger solvent. Acetone, Perc or MEK generally does the trick.
I am trying to read a bunch of late 80s QIC-24 tapes (Sun/Computervision install media).
In addition to the normal QIC band problem, I am seeing problems with the tape sticking on
the metal posts that the tape goes around to change direction towards the reels. Should I
try wiping the posts with acetone or wiping the tape with cyclomethicone? Should I be
baking the tapes? If so, what is a safe way to bake QIC cartridges?
alan 
1:08 a.m.
Al reckoned
On 4/29/20 10:01 PM, Curious Marc via cctalk wrote:
That's a good idea. Would cutting sections of an (empty) ink tube from a ballpoint pen
work?
These are generally polypropelene and should be totally inert.
Steve.
Or replacing the posts with ones machined from
Teflon or Delrin?
The posts are staked in. You might be able to make tiny rollers to go over the pins
Their working diameter isn't super critical
1 May
1 May
1:59 p.m.
Agreed. They sure are pressed in, then riveted in for good measure. You?d have to drill
them out first. Not an easy modification.
Marc
On Apr 30, 2020, at 2:18 PM, Al Kossow via cctalk
<cctalk at classiccmp.org> wrote:
?On 4/29/20 10:01 PM, Curious Marc via cctalk wrote:
Or replacing the posts with ones machined from
Teflon or Delrin?
The posts are staked in. You might be able to make tiny rollers to go over the pins
Their working diameter isn't super critical
4:50 p.m.
On 5/1/20 4:19 PM, Chuck Guzis via cctalk wrote:
On 5/1/20 1:59 PM, Curious Marc via cctalk wrote:
All of the QIC-24 cartridges sitting next to me right now have posts
that are machined with 1-2mm deep tape guides. I don't see how to
install tubing over the posts and have the guides still do their job.
As I noted, I have tried isopropyl alcohol to clean them off but they
still stick. Is this something that baking will help with? Maybe using
acetone instead of alcohol to wipe the posts down as well?
alan
Agreed. They sure are pressed in, then riveted in
for good measure. You?d have to drill them out first. Not an easy modification.
Marc
PTFE 2mm ID 3mm OD tubing is a standard size. That might fit.
--Chuck
6:40 p.m.
On 5/1/20 4:50 PM, Alan Perry via cctalk wrote:
All of the QIC-24 cartridges sitting next to me right
now have posts
that are machined with 1-2mm deep tape guides. I don't see how to
install tubing over the posts and have the guides still do their job.
As I noted, I have tried isopropyl alcohol to clean them off but they
still stick. Is this something that baking will help with? Maybe using
acetone instead of alcohol to wipe the posts down as well?
If you wipe with alcohol, can you still see crud on the posts? If so,
you'll need something stronger. Acetone might do, or MEK.
But if alcohol cleans the posts, that's not the problem. You could try
backing, but I don't think that will work either if the problem is in
the binder.
--Chuck
28 Apr
28 Apr
3:58 p.m.
Out of curiosity has anyone tried running tapes at different temperatures,
for instance in a relative cold or hot environment? Either on a simple
winder or even a recovery drive.
On Tue, Apr 28, 2020 at 11:47 AM Chuck Guzis via cctalk <
cctalk at classiccmp.org> wrote:
I'm a bit surprised that this is even a
"thing" in the audio business.
Restorers have been baking audio tapes for a long time.
One thing not discussed (maybe it doesn't occur in audio) is that there
can be issues in binder formulation, at least in digital tapes. In
particular, 3M tapes, most notably Scotch 701 and 777 formulations, have
an issue where the binder "liquefies" under motion and solidifies when
tape motion slows or ceases. So, you may be running a tape through a
drive just fine and then suddenly, everything freezes up as the tape
becomes firmly "glued" to the heads or other objects in the tape path,
usually with a loud squeal.
In the current batch of 60 tapes from the late 60s-mid 70s, every single
3M tape exhibited this behavior. It didn't matter if they'd been baked
or not. There was a note of this on Ed Thelen's site where someone had
encountered this and given up.
Isopropanol does not clean the sticky deposits from equipment--you must
use a stronger solvent. Acetone, Perc or MEK generally does the trick.
Rather than try to clean the gunk off the tape, which is probably a
fool's errand, I coat the tape with cyclomethicone, using a felt
applicator in my cleaning machine--it doesn't take much to create a
slippery film on the tape surface, perhaps 10 ml will do a 2400' tape.
Cylcomethicone is non-toxic and relatively inert--and is somewhat
volatile, so that it evaporates in a couple of hours, leaving the tape
as it was. Very slippery stuff, so don't spill it on the floor! It
does not appear to have a solvent effect on the binder, as nearly as I
can tell. It also doesn't appear to bother the equipment either.
I've achieved 100% success using this method.
I think it's interesting that tape quality tends to better the older the
tape. Audio Devices, Ampex and IBM Series 500 tapes tend to survive the
best. Memorex seems to get worse, the younger it is. (e.g. MRX III
tends to behave better than MRX V).
For whatever it's worth,
Chuck
4:05 p.m.
sony PR-150 will jam a machine up and makes a squeeking type noise as well.
then theres sticky shed syndrom that leaves a nasty mess caugh shamrock
tape caugh caugh
On Tue, Apr 28, 2020 at 1:47 PM Chuck Guzis via cctalk <
cctalk at classiccmp.org> wrote:
I'm a bit surprised that this is even a
"thing" in the audio business.
Restorers have been baking audio tapes for a long time.
One thing not discussed (maybe it doesn't occur in audio) is that there
can be issues in binder formulation, at least in digital tapes. In
particular, 3M tapes, most notably Scotch 701 and 777 formulations, have
an issue where the binder "liquefies" under motion and solidifies when
tape motion slows or ceases. So, you may be running a tape through a
drive just fine and then suddenly, everything freezes up as the tape
becomes firmly "glued" to the heads or other objects in the tape path,
usually with a loud squeal.
In the current batch of 60 tapes from the late 60s-mid 70s, every single
3M tape exhibited this behavior. It didn't matter if they'd been baked
or not. There was a note of this on Ed Thelen's site where someone had
encountered this and given up.
Isopropanol does not clean the sticky deposits from equipment--you must
use a stronger solvent. Acetone, Perc or MEK generally does the trick.
Rather than try to clean the gunk off the tape, which is probably a
fool's errand, I coat the tape with cyclomethicone, using a felt
applicator in my cleaning machine--it doesn't take much to create a
slippery film on the tape surface, perhaps 10 ml will do a 2400' tape.
Cylcomethicone is non-toxic and relatively inert--and is somewhat
volatile, so that it evaporates in a couple of hours, leaving the tape
as it was. Very slippery stuff, so don't spill it on the floor! It
does not appear to have a solvent effect on the binder, as nearly as I
can tell. It also doesn't appear to bother the equipment either.
I've achieved 100% success using this method.
I think it's interesting that tape quality tends to better the older the
tape. Audio Devices, Ampex and IBM Series 500 tapes tend to survive the
best. Memorex seems to get worse, the younger it is. (e.g. MRX III
tends to behave better than MRX V).
For whatever it's worth,
Chuck
9:38 a.m.
At 05:56 AM 4/28/2020, you wrote:
Lower right pic on "layers in contact" slide, looks like it was inverted...
- John
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