[Hallicrafters] S-120 receiver - celloluse nitrate lacquer?

[Richard Knoppow]

----- Original Message ----- 
From: "Peter VK6PM" <peter_may at optusnet.com.au>
To: <hallicrafters at mailman.qth.net>
Sent: Sunday, March 24, 2013 7:22 PM
Subject: [Hallicrafters] S-120 receiver - celloluse nitrate 
lacquer?


>
>
> I've been discussing off-group whether the clear lacquer 
> used on the
> front panel of the S-120 might be celloluse nitrate 
> lacquer.
>
> You might recall that nitrate is unstable, early movie 
> films pretty
> well self destructed before the introduction of "safety 
> film".
>
> I think that is what's happened to the S-120. The lacquer 
> has "gone
> off". The metal underneath looks OK.
>
> The problem may be present on other S-120s. I wonder if 
> other people
> have discovered similar front panel damage?
>
> Can people also check under the plastic knobs of their 
> S-120s and
> look for anything strange, blue and gooey?
>
> I'm not sure, but this might be caused by off-gassing of 
> the nitrate.
>
>
> Maybe we have discovered a new challenge to keeping these 
> sets
> presentable.
>
> Does anyone have insight as to what clear lacquers were 
> used on these
> later Hallicrafters sets?
>
> Regards
>
> Peter VK6PM

         I don't think this is caused by cellulose nitrate 
lacquer but use your nose and see if there is an odor of 
camphor.  That _sometimes_ but not always accompanies the 
decomposition of nitrate.  Clear cellulose lacquer may also 
be made from various types of acetate which might cause a 
gooy residue.  Decomposing cellulose acetate is often 
accompanied by the odor of acetic acid or vinegar.  Although 
a clear lacquer of this sort might have been used I am 
doubtful.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com