Date:         Sun, 29 Jul 2007 13:57:21 +0200
Reply-To:     Association for Recorded Sound Discussion List
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Sender:       Association for Recorded Sound Discussion List
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From:         George Brock-Nannestad <[log in to unmask]>
Subject:      Re: De-clicking (serious)
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In-Reply-To:  <000a01c7d175$44a9dc70$6b01a8c0@TOMOFFICE>
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From: Patent Tactics, George Brock-Nannestad

Hi Tom and Steve and lurkers

re: Crazy Glue

Crazy Glue (cyanoacrylate) - a commercial product for the home user and 
similar products used to be an extremely good solution for 78s. The reason 
was two-fold: when it was the liquid, not the gel, it had an extremely small 
viscosity and very good wetting properties, which meant that it would be 
sucked into the narrowest crevices/capillaries. The curing only occurred when 
oxygen was absent, so closing a crack would cure the polymer. I have a nasty-
smelling liquid which will make even completely open patches of polymer cure 
into a clear acrylic, and it was used for professional construction work, and 
I have never needed it for records.

What remained on the surface could be wiped away with a paper towel - 
capillary action. If you did that quickly there was no corrosion. If you left 
it, it would become a sort of film that was easily removeable under a 
microscope (essential for all this kind of work). When a crack was too wide - 
this could easily happen if the record was warped as well as cracked, and if 
the flattening prior to the cementing was not entirely perfect, the polymer 
would not cure - too much oxygen. This is where childrens playdough came into 
its finest professional use: a blob on each side of the record, bridging the 
gap and excluding oxygen, would make the polymer cure. 

However, they have changed the formula for Crazy Glue and similar home 
products: it now cures due to exposure to humidity - a completely different 
and quite useless feature for my purpose. Possibly the shelf life of the 
product is better. I stopped teaching the restoration methods at the School 
of Conservation in Copenhagen in 1998 and have not had much need since, so I 
have not checked the market for professional cements, but I do believe that 
Loctite (R) has products that still work according to the "old" principle.

Kind regards,


George

P.S. My course in restoration also taught how to forge and sharpen tools 
suitable for 36x magnification and fine-motor skills.




> Hi Steve:
> 
> Yes, all of what you say is absolutely true! And moreso with LPs because of
> smaller grooves 
> (although disco singles have the widest/deepest grooves of any LP since the
> advent of 0.7 mil 
> stylii). Like I said, we were shocked (shocked!) that it worked.
> 
> By the way, I'd be reluctant to use real-deal Crazy Glue on shellac. No
> chemistry facts to back me 
> up, but since shellac seems more fragile and "softer," I'd worry that Crazy
> Glue would eat away the 
> edge on which it was applied and thus assure the "pie slice" wouldn't fit
> correctly. Might be a 
> phantom menace ...
> 
> -- Tom Fine
> 
> ----- Original Message ----- 
> From: "Steven C. Barr(x)" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Saturday, July 28, 2007 7:25 PM
> Subject: Re: [ARSCLIST] De-clicking (serious)
> 
> 
> > ----- Original Message ----- 
> > From: "Tom Fine" <[log in to unmask]>
> >> In another case, I was doing a job transferring a large collection of
> 12"
> > dance-mix singles for a DJ
> >> (he was going all-digital, actually using his iPods as the players). A
> couple
> > of the records were
> >> cracked  or chipped on the edges. In one case, we found the pie-shaped
> slice
> > that broke out of the
> >> edge. I still can't believe this worked, but we were able to very
> carefully
> > glue it back into place
> >> with Crazy-Glue, using a sewing needle to apply the glue in the
> needle-thin
> > part of the vinyl under
> >> the grooves. I really couldn't believe it when it played very well with
> just
> > one big tick at the
> >> "tip" of the pie-slice. I do not expect to get that lucky ever again.
> The
> > client was a really nice
> >> guy or I would have charged extra for the awful music content of the job!
> ;).
> >>
> > I have tried a number of times to similarly repair broken 78's which had
> "bites"
> > (and I had the "bitten" piece as well...!). My experience was that these
> could
> > be
> > Crazy-Glued"...but, there was always a problem if the arc of the "bite"
> was
> > tangent (or whatever you call the meeting of two opposite-direction
> arcs...?!)
> > to the almost-circle of the playing-groove spiral at some point. Remember
> that
> > the playing groove is about 3 mil (.003") wide...so if you add a layer of
> glue
> > around .001" or more, the needle/stylus can easily slip into the wrong
> groove
> > at the repaired spot...!
> >
> > Steven C. Barr
> >