Perhaps some of you might be interested in experimenting with "misuse" of
some commonly available "finishes". It is hard to get two component
paints or anything approaching other commercial paints in terms of
durability. However, it is not too hard to use epoxy intended for gluing
or casting to provide a quite tough and adherent finish. One which works
may not be available to you under the same name but it is called "UHU Plus"
here. Today it is no longer so marked but older packages were identified
as being the same as Araldite. I assume it still is like Araldite and it
looks the same, but a change in composition is possible. You almost surely
can buy products using the same composition. I believe these can be
thinned by using mineral spirits or "white spirit". Do the thinning after
mixing or else be careful about the ratio of thinner to epoxy components so
when you blend them the desired ratio of catalyst to resin is maintained.
This will make a clear finish which you can apply on top of chemically
blacked brass to preserve it (or on bright brass!)
An epoxy which you will not so easily buy is 2850FT from Emerson & Cuming
(I am sorry if I failed to get the spelling exactly correct.), but this
costs us about $25.00 per kilogram and works as a fair, black paint. Here
you really should be careful with mixing and I strongly recommend thinning
only after mixing of the two components (and stir the resin before adding
catalyst.) This can certainly be thinned with acetone and I believe I also
had success with mineral spirits as well because I painted a large object
on which I would have been afraid to use acetone (acetone is pretty
effective at destoyong many paints and a part of what I was coating was
already painted.). The final mixture is not easy to apply but you can get
a dilution adequate to give decent results. I have never tried spraying
though it would be interesting, BUT USE A SPRAY BOOTH AND/OR OTHER LUNG
PROTECTION IF YOU TRY IT.)
After the solvent has evaporated you can bake either of these epoxies which
increases the bond strength to the brass or whatever, and helps the
products to flow, giving a smoother result.
Thr finishes will normally be glossy so they may not be ideal inside a
camera but they should be excellent outside, for parts where the glossy,
black look is desired.
Both epoxies are tough, but the black 2850 FT contains fairly hard
particles which ought to increase resistance to abrasion compared to most
unfilled finishes.
Please experiment to find the best solvent (others will almost certainly
also work) and amount of thinning.
Good luck!
Bob
Dr. Robert Mueller
Institut für Festkörperforschung, FZ-Juelich
D-52425 Juelich, Germany
phone: + 49 2461 61 4550 FAX: + 49 2461 61 2610
email: [EMAIL PROTECTED]
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