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Re: [ARSCLIST] Repair



Eric has covered it nicely...I never use glue either. Fitting the pieces
together and using Scotch Tape on the edges has always been my method, unless
the disc was warped before breakage occurred, in which case my first priority
is to find out if another copy exists. Tape can also be applied carefully along
the break on the side you're not playing, provided that the disc is not likely
to flake along the broken edges (if it DOES, you're losing more playable
surface). By "applied carefully" I mean lightly, and use only Scotch Magic Tape
which is removable.

As for laser turntables, I have yet to hear one good word about them for our
purposes, and the one transfer I had done on one (from a unique test pressing
which had been left without a sleeve for decades) sounded worse than the
results I used to get from normal playing and using the SAE 5000. And that's
pretty bad.

dl

Eric Jacobs wrote:

> I still try to avoid glue altogether.  Getting the glue residue
> out of the grooves, trying not to form a "bead" in the groove
> area - these are all unavoidable issues, labor intensive to
> correct and/or work around.  For example, one side might glue
> up beautifully, but gravity is pretty hard to avoid, so the
> other side may not.  I've taken junk 78s, intentionally broken
> them for experimentation on gluing technique, and this has been
> my experience.  Note that Krazy Glue (consumer cyanoacrylate
> has some issues: (1) the current formulation is more "gel-like"
> so it doesn't "wick" properly; (2) the set time is too long;
> (3) if you make a mistake it's truly irreversible (biggest
> liability).  I'm still on the hunt for an industrial anaerobic
> formulation of cyanoacrylate with low surface tension and fast
> setting time to experiment with - I think this might be viable
> in some limited applications.  But again, I avoid glue for the
> most part.
>
> Perhaps as important as "tight" is "flat".  Through the use of
> precision flat/clear discs made of semiconductor grade acrylic
> machined to high tolerances, I create a sandwich that allows me
> to safely transport, clean, play and flip a broken disc without
> gluing it.  I also sometimes use sorbathane mats along the way,
> which have a natural tackiness to them, to hold things together
> without glue.
>
> If anyone is interested in purchasing such discs, feel free to
> contact me off-list.  I get the discs machined in batches in
> order to get the cost down since they get machined on expensive
> machine tools with special end mills.  The discs are made for
> handling broken 16-inch acetates on glass substrates - something
> you'd never want to glue, but I can have them made in smaller
> sizes if there's enough interest.
>
> Regarding laser turntables, if it won't play with a stylus, it
> will not play with a laser turntable.  I've tried every which
> way to Sunday, and laser turntables have all the same tracking
> issues as a well-designed properly-aligned stylus turntable.
> After all, the laser turntable is designed to mimic a stylus.
>
> The primary advantage of a laser turntable is that you may not
> hear the pop from the break between the pieces.  If the break
> is bad where the mating edges have been chipped, even slightly,
> you will hear the break on the laser turntable as well.
>
> There are tricks to making the break inaudible on a stylus
> transfer.  Choice of cartridge and EQ are critical, giving you
> options in post-processing that might not otherwise exist.
>
> With a stylus turntable, where tracking through the break is
> problematic (and perhaps impossible on the laser turntable) you
> have options for dynamically adjusting the anti-skate and
> vertical tracking force (depending on the townearm) that are
> not available with a laser.
>
> The laser turntable works best with clean unchipped breaks on
> discs without warp.  Otherwise a stylus works a bit better in
> my experience.  In general, it always requires some
> experimentation as the laser may surprise you one way or the
> other.
>
> There are also tricks for getting rid of warp on 78s, but
> that's a whole 'nother thread...
>
> Eric Jacobs
>
> The Audio Archive
> tel: 408.221.2128
> fax: 408.549.9867
> mailto:EricJ@xxxxxxxxxxxxxxxxxxx
>
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx]On Behalf Of Nipper
> Sent: Saturday, November 19, 2005 8:37 AM
> To: ARSCLIST@xxxxxxxxxxxx
> Subject: Re: [ARSCLIST] Repair
>
> True Steve,
>
> The trick is to get the repair as tight as possible (squeezing all of the
> excess glue to the surfaces so that it can be removed by sponging with
> water).  It could be better accomplished with some sort of wide clamp or
> clamp array instead of the rubber bands.
>
> Martin
>
> ----- Original Message -----
> From: "Steven C. Barr" <stevenc@xxxxxxxxxxxxxx>
> To: <ARSCLIST@xxxxxxxxxxxx>
> Sent: Saturday, November 19, 2005 12:29 AM
> Subject: Re: [ARSCLIST] Repair
>
> > ----- Original Message -----
> > From: "Nipper" <nipper@xxxxxxxxxxxxxx>
> > > I've had great success with 78s using good old Elmer's glue, a few
> rubber
> > > bands and a good working knowledge of how a stylus tracks a groove.
> It's
> > a
> > > fairly strong hold yet water soluable so if you make a mistake you can
> > > always soak it loose, clean the contact surfaces thoroughly and try
> again.
> > > On the other hand there are plenty of incompetent Krazy glue formula
> > repairs
> > > that have been screwed up once and for all.
> > >
> > From my experience, it is effectively impossible to repair a broken 78
> > if the break runs more-or-less "parallel" to the groove at any point.
> > The layer of adhesive, although thin, still dislocates the groove path
> > at the point of breakage far enough that the stylus doesn't track
> > the correct path...remember that the groove is about .003" wide,
> > so if the adhesive is more than .001" thick the path is effectively
> > half-a-groove out of position.
> >
> > Steven C. Barr


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