[R-390] Removing MFP

[djed1 at aol.com]

I've used the white polishing compound on both old and newly-painted front panels with no problems.  I agree that the
heavy rust colored compound is probably too agressive. 
 

 

 

-----Original Message-----
From: Perry Sandeen <sandeenpa at yahoo.com>
To: r-390 <r-390 at mailman.qth.net>
Sent: Mon, Mar 26, 2012 8:14 am
Subject: [R-390] Removing MFP



Some of the BA’s we have/get were coated with MFP which causes several problems.

Background.
A long time ago the US military found it had a problem in some situations with 
mold and/or fungus thriving inside electronic equipment so they developed a 
spray material that was applied to combat the problem. It is a brownish looking 
material on wires and solder joints and adds a somewhat golden look to aluminum 
chassis parts 

Our current problems with MFP
Wires and terminals coated with MFP makes repair difficult as the wires become 
stiff and tend to glue together in wire harnesses.  Sometimes adding to the 
problem is the spray coating was very heavy.

Terminals covered with MFP must be scraped clean before soldering or one gets an 
ugly residue.  Scraping the stuff off can be difficult.  I’ve found that a 
stainless steel cuticle pusher, about $4 at beauty supply stores, sharpened a 
bit on a grinding wheel worked best for me.  I tried using a Xacto knife.  For 
me in many cases the blade was too large or wasn’t good for prying, but then it 
wasn’t designed to pry.

I had no success with either alcohol or acetone.  A list member suggested 
AFAICR, Goof-Off.  I tried it but it didn’t work on the MFP. I’m still looking 
for a chemical cure that isn’t a carcinogen.

Removing MFP from aluminum parts.
For removing the stuff from chassis parts thanks to Walter Wilson, I learned of 
an automotive product called NEVER-DULL by Eagle One.  It is about $5 for a 5 
oz. and comes is a round metal can.

It is a bit of a strange product.  It seems to be cotton wading moistened with a 
faint kerosene-like odor fluid.  To use it, one pulls out a wad and then rubs 
the MFP coated metal.  The wading turns black in color as you rub.  You keep 
moving the wadding around until the whole piece is black. The results are 
spectacular.  Now the downside is that this takes a great deal of time and can 
be expensive.  To do both sides of one R390A side panel might consume a whole 
can and several hours.

Somewhat faster (relatively speaking) and considerably cheaper was using a 
product marketed by Turtle Wax called POLISHING COMPOUND & scratch remover.  It 
is a white cream with some abrasive in it so the finished shine was a bit duller 
than using NEVER DULL.  I have yet to try using NEVER DULL as a final polisher 
for metal done with polishing compound.

For very heavy MFP or corrosion I used The Turtle Wax product rubbing compound. 
This is a rust colored paste that removed MFP fairly rapidly.  It is about the 
same price as the polishing compound but leaves a duller finish.

The level of finish “shine” desired is totally subjective.  The amount of MFP 
applied seems to very greatly.  My best advice is to try any or all of these 
products in an inconspicuous place and see how they work in your particular 
situation.

A final note.  I also tried these products on an old plain SP-600 side panel and 
got the same results.  IMNSHO, I believe any BA metal polished with these 
products makes for a very good looking radio.

Still on the to-do list is to see if front panel paint can be shined up with the 
NEVER DULL or the polishing compound. I personally wouldn’t use rubbing compound 
on a painted surface because it is so aggressive.

Perhaps others would share their experiences.

Regards,

Perrier

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