[ARC5] Tropical Coating

[WA5CAB at cs.com]

Yes.  At least in the generic sense.  I don't recall ever coming across a 
document giving the actual chemical composition.  I did once track down a 
source of solvent for it, but cost versus minimum order quantity versus shelf 
life resulted in no purchase being made.  But it is Moisture and Fungus 
Proofing varnish.  Developemt began after the invasion of Guadalcanal and because 
of limited availability, until roughly mid-1944 its use was restricted to 
items going to the PTO and CBI.  If you look around the outside of the 
receiver, you should see a stamp saying "MFP", and maybe a date.

It is relatively brittle (at least 60-70 years on).  It should be removed 
from solder joints before doing any parts replacement.  I can attest that it 
clogs up de-soldering equipment.

In a message dated 2/21/2010 10:10:21 AM Central Standard Time, 
hyperlabs at aol.com writes: 
> My BC-454 has (what I surmise to be) a tropical coating on the internal 
> underside wiring and components. It's slightly yellowish and has a kind of 
> resinous fragrance when the unit is warm. Does anyone know what this 
> material is? Looks quite effective...
> 
> Jim
> N3ZJ

Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480