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Conditioning Silica Gel

One of the very useful tools for me is a desiccation chamber for drying out wet things, like uncured tordonshell, a fresh plaster casting, wet wood, or something similar.  I achieve such a chamber by using either a Gamma pet food container or a five-gallon pail with a Gamma retrofit sealing lid.  I load the chamber with desiccated silica gel and it is ready to do its work.  Put something damp in there, tighten down the lid, and the moisture gets sucked out of whatever it is you are trying to dry.

But the silica gel eventually gets damp itself, or at least adsorbs all the water being removed from the object in question.  Fortunately silica get can be re-conditioned an unlimited number of times.  My regimen for drying it out fully involves one of two routes typically.  For much of the year I simply place a mass of the crystals into a slow-cooker and turn it up.  In about 12-24 hours of cooking there the gel achieves a moisture content such that a sealed container holding it after cooling is at about 2-3% RH.

Another option for me in the winter is that I can dry out the gel in pans on top of kerosene heater I sometimes use to jump start the heat in the morning, or leave it on when the temperature is chilly but not yet frigid.  I keep a plate of aluminum on top of the heater to increase the heating efficiency by integrating a large radiant plate, and this often serves as a tray for heating things in the winter.  As with the slow cooker the total cooking time is somewhere between 12-24 hours, with the same 2-3% RH end point.

In either case, the slow cooker or the kerosene heater, I cover the batch overnight when I turn off the heat source, to prevent it from adsorbing moisture from the night air.

Silica gel can also be conditioned to a specific RH buffer but that is another topic.

Where Did I Put That Stinking Knife Handle?

Recently I was sitting down ready to incise the pattern into the block that would become the pattern for the mold for making my soon-to-be-available Blend 31 block wax.  It was at that moment that I realized I had put the handles for my detail knives someplace for some reason I could not remember.  It was not that I had misplaced one of my handles, I could not find any of them, suggesting I had collected them for some purpose that I could no recall.  Fortunately they will be found as soon as my task is completed.

In the mean time, I needed a handle for the knife blades I needed to use.  So I made one.

Taking a piece of dowel stock from inventory I sawed a small slot with a fine Japanese back saw, inserted the blade into that and bound it with twisted copper wire, much in the same manner as quill brushes.  It worked just fine for the carving of the mat board that was the detailed surface of the block pattern.

An hour later I had the design incised into the surface and the block was ready for making the rubber mold.


And sure enough, the box with my micro tools was found right after this was finished.  Sigh.

Up A Creek Without A Polissoir

At the recent gathering of the Professional Refinisher’s Group one of the presenters was addressing a topic that would have fit seamlessly with the use of polissoirs.  When I asked the host for his, I was informed it could not be found.  I canvassed the group and none was to be found.  Even I had not brought one with me!  While I normally travel with my rolling Store for some reason this time I did not.

But with a little thrashing around and some yeoman’s help from TomD we made one that worked enough or the task.

The starting point was the old shop broom, a roll of twine, and my dull Victorinox multi-tool knife (dull because I had cut some wire and had not sharpened it.  My bad.)

After cutting of some broom fibers we set about trying to find the string necessary.  We could not find anything really robust, what we found was some soft twine similar to macrame yarn.  So we used what we could find.  (I think the broom went back to hang on its nail, ready to go to work albeit a little less effectively).

Working carefully, and celebrating the fact that my broken arm from two years ago has recovered almost all of its dexterity and strength, I started putting it together.  My biggest challenge was trying to work right up to the limit of the tensile strength of our soft twine.  Normally I use heavyweight waxed linen cord, which I literally cannot break by hand, resulting in a polissoir so tight it has a sharp sound when rapped against a hard surface.  This undertaking did not yield such a result, but the polissoir was tight enough to serve well enough for the task at hand.

I trimmed one end  and we put it to work.

I’ll know to never travel anywhere without a polissoir in the future.  Note to self: when packing for a trip, it’s glaucoma meds, toothbrush, and a polissoir.

All A-buzz

Many times in the studio I need to shake something, just a teeny bit.

For example, when casting plaster or plaster like materials, such as ceramic media for lost-wax casting investment, it is sometimes necessary to tap on the mold container to dislodge air bubbles that all too often get lodged against the surface.  If they remain there the casting will be diminished, even ruined.  Many years ago I looked into getting a vibration table for buzzing the molds while the medium was still liquid, loosening the bubbles to rise to the surface.  After pricing the available devices I decided to go another route.

What could I use to cut the cost of a vibrating table down to near-zero?

Hearkening back 55 years to my times with Stan the Barber I recalled two things — Stan always had the latest comic books for the boys to read, a real treat for me because we were too poor to get them, and the tickle of the vibrating electric clippers on my neck when he was trimming up.  Could electric hair clippers be part of the answer?

The next time I ran across some clippers at the thrift store I decided to roll the dice with a buck-and-a-half for the clipper.  I combined the tool with some scraps of wood, two pieces of plumbing strap and a few screws.

Viola’.  A vibrating table for a couple bucks and a couple minutes.