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I have just bought myself a Freiberger drum sextant,
used, made in 1976. I am happy with its overall condition.
It works well.  Other than a few scratches in the middle
of the frame, nothing looks terribly worn. I want to start
out on the right foot with it, of course.

If anyone has any tips or warnings to offer on disassembling
and reassembling this sextant, I'd really appreciate learning
more about it.

Why would I want to do this?  There is a small amount of corrosion
on some of the screws.  I think the thing to do is to remove
the scope, mirror, and shade assemblies, wash the sextant
to remove particles, the completely disassemble it for a
more thorough cleaning, coat the non-moving parts
(including screw threads) before reassembly to prevent
corrosion, and lubricate the moving parts.

So far, I have only been bold enough to remove the handle
by unscrewing the upper leg stub and the large lower
screw.  I see a waxy substance in the screw holes.
I have no way of knowing if it was ORIGINALLY waxy,
or if this is a grease that has gone waxy with age.
In this forum, I have seen the following recommended
for protection from galvanic corrosion:
* Never-Seize
* Lanocote
* TefGel
* Krytox with corrosion inhibitors(which Jared Sherman
frequently recommends highly for a number of reasons)

I don't see any recommendations for:
* Hydrophobic dry coatings (like sailkote, which contains Krytox)
and I wonder why.  Jared Sherman is of the opinion that these
spray-on coatings just don't last very long.

I am eager to take the sextant apart, but I want to be
prudent.  I understand how to create a proper workspace,
label and lay out each and every part, put screws back into
same holes they come from, and take pictures along the way
to remind me what it ought to look like when I'm done.

It's just that I've never done this before, and there is no
shop manual.  It looks like a straightforward job, but I
really would appreciate hearing more from anyone who can
give me a heads-up on any stupid thing a beginner is likely
to do wrong.

And I am up in the air about what to put on the screws before
I put them back in.

Thanks for your help!

Renee

   

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