[ARC5] MFP - how to remove?

[don davis]

I would be reluctant to take any sort of grinding tool to any unknown metal
surfaces from that era and earlier.  There are lots of real nasty things:
cadmium, chromate, zinc, lead, beryllium, BeO, radium, spent uranium,
mercury and others that show up in strange places.  If you heat these or put
powder in the air you could be in trouble health-wise.  Also, folks in those
days didn't really know or care about safety and identification of hazards.

 

Things like paper, and other organics were sometimes treated with mercury
compounds to inhibit fungus, and DDT wound up in paint and coatings and
over-spray from normal use.  PCBs which form dioxins at high heat were used
in high voltage / power switch gear (but I saw a lot of these in USAF radar
and B52 electronics as well).  We used carbon-tet and leaded gas for
cleaning solvent.  Sometimes while smoking a Marlboro.  

 

I don't know what's in MFP; I've performed a literature search and have very
few credible sources.  Some believe mercury was used, DDT, lacquer, paint,
shellac, etc.  Consensus is scrape off the area you're are going to rework,
use only enough heat to get it done, and area well ventilated, and avoid
disruption of intact metal surfaces.

 

I'm NOT a chemist, so I won't argue against any better knowledge from
others, but I was in aerospace engineering 35 years,  and 9 years in Air
Force on B52 electronics and flight simulators  where I spent a lot of time
working around this stuff and designing a lot of it out of modern equipment.
The "hot advice" in those early days was "if in doubt, dig a hole and bury
it."

 

73 de don ad6pb

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