Ignoramus19508 wrote:

Another question. These circuit boards were originally sprayed with
some coating. I surmise that the purpose of it is to prevent
accidental shorts due to dust contamination or other debris being
drawn into the unit.

This was, in fact, a great thing, as this particular welder had so
much dust inside, that I was shocked. The amount of dust was nothing
short of incredible, maybe 5 lbs of dust settled on absolutely
everything. I took this welder out of its protective shell, vacuumed
it, and then blew the dust out using compressed air (outdoors). The
truly amazing thing, is that it was still functioning fine with all
that dust inside.

Thanks to the Miller company.

Having said that, I would like to apply that coating to the areas that
I re-soldered. What is that coating?

i


It is a conformal coating. General Cement in Rockford, Illinois,
makes a silicone based version called "Print Koat", as well as the
solvent.

Part No. 22-203 - Print Kote Conformal Coating
The ultimate coating for PC boards. Provides a
protective shield to resist environmental
contaminants. Prevents arcing and shorting. Air dry
15-30 minutes. May be baked at 200°C for 30-60

and

Part No. 22-209- Print Kote Solvent
A solvent to remove silicone and other types of
protective coatings from PC boards. Required when
modifying PC boards or replacing components
where the protective coating interferes with the
desoldering and resoldering operation.

Allied Electronics stocks it.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida