LISTSERV mailing list manager LISTSERV 16.0

Help for ARSCLIST Archives


ARSCLIST Archives

ARSCLIST Archives


[email protected]


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

ARSCLIST Home

ARSCLIST Home

ARSCLIST  February 2012

ARSCLIST February 2012

Subject:

Re: offgasing from baking tapes

From:

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

Reply-To:

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

Date:

Mon, 20 Feb 2012 15:58:06 -0500

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (130 lines)

Hi, Katie,

I'm not talking about SCBA type respirators, just the step up from the 
dust mask at the Home Depot.

The image of the NYPD officer in the Wikipedia article shows something 
close to what I purchased at Home Depot.

http://en.wikipedia.org/wiki/Respirator

I do realize there may be protocols, etc., associated with using these 
in the workplace, and I know nothing about that. But, I would much 
rather wear one of these than the simple dust mask because the dust 
masks never seem to fit well.

Yes, I realize that bad things can infiltrate through the eyes as well, 
but I am careful not to rub my eyes.

MARIE: Did you not install the refrigerator in the processing room? I 
thought you had done that, too, and named it "Richard" <smile>.

Katie, as to your other questions:

 >>if you are reserving seperate equipment for baking moldy tape, are 
you also reserving seperate equipment for playing it?

Yes and no. I have a headless mold transport in the garage, but I clean 
the tape with a dilute chlorine bleach solution that has not proven 
harmful to the tapes, but should be harmful to the mold. The tape is 
wiped end to end and placed on a clean(ed) reel.

The tape is then brought into the studio for transfer.

 >>Our audio archivist and I have only come across moldy tape once since 
we've been doing this ( a few years), and we we're able to make the 
decision to de-acession the tape in that instance.

I get some work from large corporations who don't want to make that 
decision and also don't want to risk a lawsuit. I am careful. I've done 
research. I don't think I'm taking an excess risk. I usually request no 
boxes, no paper, and ship them to me in plastic bags.

 >>I've been wondering about differentiating between different tape 
bases before baking. Acetate and PET - there are a couple of ways that I 
know of if it were really in question (using polarized filters, for 
one,I think - but if there is an easier way, please let me know) -

In many collections, you CAN rely on the box as your first source of 
information. The easiest thing to do is to hold the tape up the a strong 
light. If you SEE light coming through the tape pack (the 1/4-inch 
dimension) i.e. through the edges of the basefilm, then it is acetate. I 
understand this is reversed for film, but if you take some Scotch 111 
(very common acetate tape) and hold it up so you're looking at the disc 
of the reel, you'll see light coming through.

While this is not 100% accurate, I do know of a few instances where 
baking has helped non-back-coated tapes, by and large all tapes that 
need to be baked are back-coated.

The worst of the bunch--the Ampex/Quantegy 406/407456/457 tapes were 
plentiful AND need baking. These are black backcoat and brown magcoat. 
If I get something that looks like this, it is baked as you can do more 
damage winding through a tape that needs baking than baking it.

PVC tape is very rare and should not be baked, but I don't know how you 
differentiate it from PET.

NOTE: Scotch called their acetate base "Plastic" and often used the 
DuPont trademark "Mylar" for their PET based tapes.

For 3M and BASF(etc) there are good lists at:
http://www.aes.org/aeshc/3mtapedoc.html
http://www.aes.org/aeshc/basftapedoc.html

These (and some other useful resources) are listed in the middle of
www.aes.org/aeshc/

I think there is one 3M PVC tape listed. BASF and related companies made 
more, including the 1944 I.G.Farben Magnetophonband TypL which was 
homogeneous--the mag particles were not coated on, but rather were 
embedded in the basefilm.

One other resources is I attempt to keep a current list of degrading 
tapes on my website
http://richardhess.com/notes/formats/magnetic-media/magnetic-tapes/analog-audio/degrading-tapes/

Here is a tag sort of my blog articles (accessible in the bottom half of 
the sidebar)
http://richardhess.com/notes/category/archive-operations/tape-aging/

This sort also might be of some interest (and has some duplication)
http://richardhess.com/notes/category/archive-operations/archival-practices/


 >>but do we need to worry about ruling out PVC as well?

See comments above.


 >>I'm certainly not enough of a chemist myself to be able to take the 
laundry list of potentially harmful components I recieved and trace it 
back to any particular of the makeup of a tape, unfortunately.

Benoit Thiebaut did some research for Prestospace on u-matic video 
cassettes and identified four different chemistries for the same 
manufacturer/type number. At least some of the problem is attributable 
to chemical reactions that did not complete as expected or designed. At 
this point, I don't think we'll ever obtain enough information to 
reverse engineer all the different tape formulations. There will never 
be a pool test kit is the consensus of the chemists I've talked with.

You have read my paper, no?

My paper on tape degradation that was originally presented at the Audio 
Engineering Society's 121st convention in October 2006 in San Francisco 
was published in the ARSC Journal in the Fall of 2008. It is available here:
http://www.richardhess.com/tape/history/HESS_Tape_Degradation_ARSC_Journal_39-2.pdf

I hope this helps.

Cheers,

Richard

-- 
Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada           (905) 713 6733     1-877-TAPE-FIX
http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

March 2024
February 2024
January 2024
December 2023
November 2023
October 2023
September 2023
August 2023
July 2023
June 2023
May 2023
April 2023
March 2023
February 2023
January 2023
December 2022
November 2022
October 2022
September 2022
August 2022
July 2022
June 2022
May 2022
April 2022
March 2022
February 2022
January 2022
December 2021
November 2021
October 2021
September 2021
August 2021
July 2021
June 2021
May 2021
April 2021
March 2021
February 2021
January 2021
December 2020
November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003

ATOM RSS1 RSS2



LISTSERV.LOC.GOV

CataList Email List Search Powered by the LISTSERV Email List Manager