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Tarnished bench block


#1

Hi… my bench block has become tarnished and rusty. What can I do
about it. Can I restore it and how do I keep it from happenning
again?

Thanks
Pam


#2
     my  bench block has become tarnished and rusty. What can I do
about it. Can I restore it 

Place a sheet of an appropriate grade of wet dry paper grit up, on a
good flat surface. Place the bench block on top, perhaps with a bit
of water or oil if you like, and rub it around till the surface
corrosion is removed. The degree and depth of the corrosion will
determine what grade of paper you need to start with. If it’s minor,
use 600. If it’s very bad, you might have to start with something
much coarser. Once the surface is evenly sanded, repeat with finer
and finer grades until you get to a nice smooth surface. like that
600 will give you, or finer yet, if you’ve got it. Generally it’s
not needed to actually polish the block, since as often as not,
actual buffing will make the surface shiny but slightly less flat. If
you wish a higher gloss, machine tool suppliers can sell you much
finer grade papers. Sanding up to 1200 or finer will be almost
polished. Or use the fast cutting, long lasting, but more costly, 3M
graded abrasives. Their sanding films go all the way up to something
like 2 microns, if I recall, which will appear like a low sheen
polish, not a sanded surface. You could follow with a bit of buffing
compound if you like, but it should really not be needed.

and how do I keep it from happenning again?

to start with, take some care of the block, being careful not to use
metal that is still wet with water, pickle, flux, etc. Also, don’t
place it close and 'downwind" of a torch flame, as one combustion
product of our normal fuel gasses is water vapor, which can condense
out on a cold steel bench block if the flame passes over it, even
when the part hitting the block is well beyond the visible glowing
part of the flame. Also, a little bit of light oil now and then, will
protect the block. If it gets wet, spray a little bit of WD-40 on it
(WD-40 is a moisture displacer, not really a lubricant. While it
temporarily lubes and frees up things, it’s original formulated
purpose, as indicated by the WD, is to displace water, thus helping
to prevent corrosion… It does not, however, leave much of a
protecting layer behind after it evaporates, thus the suggestion for
a little bit of light oil. Doesn’t take much.

And if you see the beginnings of rust or corrosion, the sooner you
dig out that fine abrasive paper and remove it, the less you’ll have
to remove. For very faint corrosion, just a bit of fine steel wool
may be enough.

Peter


#3

Sand the rust off (using finest grit you can get the rust off with,
polish (I use a steel polishing compound and separate polishing
buff). Spray with WD 40 to protect from dampness- clean good before
using.

Louise


#4

Dear Peter i had just finished cleaning my steel block and you worte
about down wind… no wonder my blocks always need touching up… I had
no idea… thanks as usual… they are now moved away from the down
wind of the torch… can’t believe it was that simple… calgang


#5
    i had just finished cleaning my steel block and you worte about
down wind.. no wonder my blocks always need touching up.. I had no
idea.. thanks as usual... they are now moved  away from the down
wind of the torch.. can't believe it was that simple. 

that’s just one means by which the steel on your bench can get
rusty, Calgang. but many folks solder on a block placed on their
bench pins, with the block sitting just next to the pin, and that’s
often close enough to attract some condensation. Other factors might
just be the humidity level in your shop area, or an uncovered pickle
pot nearby (worse than the torch fumes, I’d think). And often I find
that a “pounding” operation might follow a soldering and pickling
operation, and if the work isn’t fully dry after the pickling, or
worse, fully rinsed after pickling, then residual moisture on the
work can easily leave traces on the block, leading to rusting. A
little bit of WD-40 now and then to be sure the block surface is
moisture free, followed by just a tad of light oil, should help
protect and keep the surface rust free.

The bit about “downwind of the flame” is perhaps overstated, since
the flame is heated, and hot air rises. So if you’re more than
pretty close to the flame, moisture isn’t being deposited on the
block but is missing it by rising up as it moves away from the
torch… The possibility is easy to demonstrate, though. Point the
flame at the block from just far enough away so the incandescent
part of the flame is not hitting the block, but close to it. You’ll
see lots of water condensing fairly quickly. This effect, by the
way, is one of the main reasons why ingot molds need to be heated
prior to pouring. A cold mold condenses moisture, which then
explosively turns to steam when molten metal hits it, blowing the
metal back out of the mold. A hot mold not only gives you better
ingots (It lets the mold fill without so many shrinkage voids, etc.)
but avoids that condensation.

cheers
Peter


#6

Dear Peter thanks again… It was fun to see the mosisture…etc…my
shop is in the basement so it is always a problem and the mositure
machine,(senior moment) goes off quite often especially when I had a
little water in the basement yesterday… even in NJ we get a little
help to clean the floors… UGH! anyway always neat to hear from
you…caroline