In 070115 MMDigest Robbie commented:

>[ I'm sure that a precise specification exists for the specific RTV
>[ adhesive used in space vehicles, so that exactly the same product
>[ can be purchased later.  (I wish I could locate the spec...)

Actually, there are a number of different specifications depending on
the intended use of the RTV (as an adhesive or a sealant), the modulus
when cured, etc.  In the past I worked at a company with a contract
for a device for a NASA project.  The limited subset of specifications
relevant to our small device filled two large file cabinets and many of
the specifications referenced additional specifications that had to be
used in certain instances.

We used RTV products for the project, and while I no longer remember
the specification, the products used were Dow Corning 3140, a somewhat
flowable product used primarily as a coating, and Dow Corning 3145,
a stiffer adhesive/sealant product.  These were approved for use in
a device designed for long term reliability in on-orbit conditions.

I'll not enter the debate over the use of RTV in a player except to say
that there must be a distinction between _restoration_ of a valuable,
high quality instrument to original condition to preserve or enhance
its value, and the _repair_ of a less valuable, lower quality instrument
to provide years of playing enjoyment for the owner.

A true restoration must, of course be as original as possible but repair
of a less significant instrument does not require strict adherence to
original materials if newer materials can provide similar or better
life at lower cost or greater ease of use.  Or at least that's my
opinion.

Wayne Johnson

 [ Thanks for the tip, Wayne.  I searched for specs concerning Dow
 [ Corning 3145 and found that it is often cited as complying with
 [ MIL-A-46146 (all or part).  Now to locate the spec itself...
 [ -- Robbie