There have been a couple of suggestions regarding silica gel or
desiccant to stabilize the RH of the afformentioned 200 sq. ft. vault
Patricia McElyea spoke about. Conditioned silica gel works great in well
sealed artifact cases, but not in large (relative to an artifact case)
unsealed rooms. As an example, a small case 0.3 cubic metres in volume
would require 4.9 kg of silica gel to maintain an RH of 50%! Raymond H.
Lafontaine of the Canadian Conservation Institute has written an
excellent technical bulletin on the use of silica gel as a buffering
agent in the stabilization of RH in exhibition cases (CCI Technical
Bulletin No. 10 Silica Gel). It is available through the CCI at 1030
Innes Road, Ottawa, Canada, K1A OM5.

Andrea Reichert
Curatorial Assistant
Manitoba Craft Museum and Library


> Date:    Wed, 18 Nov 1998 10:19:02 CST
> From:    Patricia McElyea <[log in to unmask]>
> Subject: Re: Humidity Help!
>
> Hi All!!
>
>        I desperately need your help and advice!  Here is my situation.
>
> I have a 200 sq. ft. vault area, concrete construction on an out side
> wall.  Controlling the humidity in this area has become the bane of
> my existence!  I run a dehumidifier constantly and check it twice a
> day.  I have adjusted the temperature, contacted the AC/Environmental
> department to check it....Seems no matter what I do there are still
> humidity spikes (sometimes a much as 20% in a week).  The kicker is
> that I literally have NO BUDGET to deal with this. Any suggestions???
>
> Patricia McElyea
> Curator of Collections
> Arkansas State University Museum
> [log in to unmask]

************************************************************************
>
> Date:    Wed, 18 Nov 1998 14:07:29 -0500
> From:    Mark Erik Nielsen <[log in to unmask]>
> Subject: Re: Humidity Help!
>
> I wonder if silica gel would be a way to at least equalize the
> humidity level? Any ideas?
>
> Mark Nielsen
> Exhibit Designer/Preparator
> University of Michigan Museum of Art
> [log in to unmask]      313/647-2068
>

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> Date:    Thu, 19 Nov 1998 11:58:02 PST
> From:    Heidi Carroll <[log in to unmask]>
> Subject: Re: Humidity Help!
>
> Desiccent in bags or trays conditioned to the desired humidity level
> would be helpful in artifact cabinets.  And maybe jars of dry
> desiccent scattered around the room would help with the humidity
> problem. I can't remember specifics about drying desiccent or how
> quick it is to absorb moisture or release moisture, but I could find
> out more about it if you want.
>
> Heidi Carroll