Ken Waringa wrote that he could not find a rust-free midget bonnet, or a
new repair piece for the problem spot.
It seems to me that this is an ideal application for a chemical dip-strip
or electrolysis for rust removal. If the only problem is the rust, not
accident damage or whatever, then the rust can all be removed leaving a
clean, shiny bonnet -- albeit a somewhat perforated one. The holes
resulting from rust-through can be repaired by soldering. I'm no expert,
but this is what I would try.
>From my readings I gather that most paint & rust stripping dips are
using a solution of water and lye (the same stuff that one used to
use to clear drains)
For the electrolysis method (which apparently does not leave the metal
brittle) you must first get rid of the paint/grease/oil, then suspend
the part in a solution of baking-soda along with a sacrificial anode
of clean steel. The rest is just like the "making hydrogen" experiment
in high school chemistry except that you need a much heftier DC source.
The portions of the part closest to the anode clean up first, so how do
we deal with corrosion on the the internal bracing of the bonnet...Hmmm...
Soldering the area of highest rust damage will also protect the area
from further corrosion, as everything there will have a nice tin
coating.
The procedure is to heat up the area around the hole to over the melting
point of the body solder. Touch the solder to the heated metal and it
will flow onto the surface -- if it beads, you are not hot enough (or
else not clean enough) the solder can bridge small enough holes, then
you just add enough such that you can grind/sand the area back to smooth
once it has cooled. larger holes require a piece of clean steel soldered
into place behind, then filling and smoothing as before. (heat both
pieces to temperature, hold them together, and touch the solder to the
joint -- it will seek out and fill the space between the pieces)
So -- am I nuts?
Douglas McKinnie
72 B-GT
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