Re: [ARSCLIST] Acetate tape discolours tape box

[Tom Fine <tflists@xxxxxxxxxxxxxxxxxxx>]

Hi Parker:

So does vinegar syndrome directly relate to curled edges? If so, why are some acetate tapes badly 
curled but not vinegar-smelling?

Is vinegar syndrome related to temperature and humidity or something else?

Thanks in advance. I've always known about vinegar-smelling acetate tapes, just never known the 
details about the problem.

What we used to call "warped tape" I always assumed was caused because the tape had been warehoused 
and then stored in our attic and thus had literally warped the tape pack from heating and cooling. I 
don't recall any of that large bunch of warped Audiotape smelling like vinegar, just like dust. On 
the other hand, acetate tapes stored in our damp basement often developed mold and in the case of 
very old Scotch 111, the mold would literally eat a hole in the tape pack. In the case of Audiotape 
acetate tape, the mold would grow on the edges but could be washed off with isoprop. I also think 
the mold was fed by or grew on tobacco residue on the boxes and reels. Remember, back in ye olde 
days, studios were heavy smoking environments.

It's too bad we threw out 100+ pounds of warped tape years ago, of course keeping the reels and 
boxes. It might have been useful for research on this stuff. I just found a box of early polyester 
tapes in the damp basement and it, too, had mold growing on some reels -- spread over from the boxes 
I think. That was easily cleaned with a lightly wet isoprop cloth. No residue on the heads after 
playing. Some edge warpage but luckily it was 1/2-track tapes and not 1/4-track. Tones were right on 
at 185nWb all these years later (about 40 years in this case).

-- Tom Fine

----- Original Message ----- 
From: "Parker Dinkins" <parker@xxxxxxxxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Tuesday, October 17, 2006 12:47 PM
Subject: Re: [ARSCLIST] Acetate tape discolours tape box


> on 10/17/06 8:41 AM US/Central, Tom Fine at tflists@xxxxxxxxxxxxxxxxxxx
> wrote:
>
> > what does the vinegar syndrome do to the tape?
>
> In extreme cases, it will warp so much that 1) head contact will be quite
> poor and erratic, 2) it will not stay in the tape guides, and 3) it cannot
> be wound back onto the reel from which it came.
>
> All of these problems can be overcome to some extent by increasing tape
> tension way beyond normal, i.e., by using mechanical friction in the tape
> supply path. Not all tape players will work with the increased tension that
> may be required.
>
> Another thing that happens in extreme cases is that the tape loses mass
> (i.e., becomes noticeably lighter).
>
> ---
> Parker Dinkins
> MasterDigital Corporation
> Audio Restoration + CD Mastering
> http://masterdigital.com