Calcium Chloride was used to break up ice last winter. It
is now inside plywood and causes that wood to constantly
become wet. How does one neutralize or remove CaCl from
construction lumber. Removal, unfortunately is not an
option. Mold or mildew would be the long term adverse
consequence. How is CaCl neutralized?

In article , w_tom wrote:
Calcium Chloride was used to break up ice last winter. It
is now inside plywood and causes that wood to constantly
become wet. How does one neutralize or remove CaCl from
construction lumber. Removal, unfortunately is not an
option. Mold or mildew would be the long term adverse
consequence. How is CaCl neutralized?

By rinsing with *lots* of water.

It's a salt. Which means that, chemically speaking, it's a *very* stable
compound. Which in turn means that it won't react with too much of anything.
Nearly all chlorides are soluble in water. IIRC, one of the exceptions is iron
chloride, in which case soaking with a solution of iron sulfite might do the
trick, by producing (soluble) calcium sulfite and (insoluble) iron chloride.

But you're probably better off to find some way to replace the plywood.

IIRC, calcium chloride absorbs water like crazy and is one of the
chemicals over which we (when I worked in chemical labs a few decades
ago) used to pass certain gases to dry them. But it is not highly
soluble in water and would take a lot of water to wash it out.

MB


On 05/16/04 09:44 pm w_tom put fingers to keyboard and launched the
following message into cyberspace:

Calcium Chloride was used to break up ice last winter. It
is now inside plywood and causes that wood to constantly
become wet. How does one neutralize or remove CaCl from
construction lumber. Removal, unfortunately is not an
option. Mold or mildew would be the long term adverse
consequence. How is CaCl neutralized?

In article , Minnie Bannister wrote:
IIRC, calcium chloride absorbs water like crazy and is one of the
chemicals over which we (when I worked in chemical labs a few decades
ago) used to pass certain gases to dry them.

That's correct...

But it is not highly
soluble in water and would take a lot of water to wash it out.

... but this is not. Calcium chloride is much more readily soluble in water
than sodium chloride (common table salt).

Solubility in cold water: CaCl, 74.5 grams/deciliter; NaCl 35.7 g/dl
In boiling water, the difference is even greater: CaCl 159 g/dl, NaCl 39.1
g/dl
[Source: Handbook of Chemistry and Physics]

w_tom wrote:
Calcium Chloride was used to break up ice last winter. It
is now inside plywood and causes that wood to constantly
become wet. How does one neutralize or remove CaCl from
construction lumber. Removal, unfortunately is not an
option. Mold or mildew would be the long term adverse
consequence. How is CaCl neutralized?


You're screwed. Calcium chloride is already a neutral salt. *maybe*
you can precipitate it out as calcium carbonate by applying a strong
base, like sodium carbonate or sodium hydroxide, but you will still have
all that chloride.

I would try sodium carbonate to convert the CaCl2 to NaCl (which is less
hygroscopic) and then apply a coat of whitewash and see what that does.
(I don't think it will help much, but it's cheap)

Best regards,
Bob

In article , (Doug Miller) wrote:
In article , Minnie Bannister
wrote:
IIRC, calcium chloride absorbs water like crazy and is one of the
chemicals over which we (when I worked in chemical labs a few decades
ago) used to pass certain gases to dry them.

That's correct...

But it is not highly
soluble in water and would take a lot of water to wash it out.

... but this is not. Calcium chloride is much more readily soluble in water
than sodium chloride (common table salt).

Solubility in cold water: CaCl, 74.5 grams/deciliter; NaCl 35.7 g/dl
In boiling water, the difference is even greater: CaCl 159 g/dl, NaCl 39.1
g/dl
[Source: Handbook of Chemistry and Physics]

Oops, sorry, typos: should read CaCl2 instead of CaCl on both lines above. The
solubility numbers are correct, though.