RE: Storage unit materials

Herold Faulkner (faulkner@redshift.com)
Fri, 12 Jun 1998 17:49:27 -0700

Along these same lines Conservation Resources sells a paint that acts as a
molecular trap to absorb potentially harmful gasses....They also sell papers
and boards with the same material imbedded. The idea being that you can
simply remove and replace these boards when they have lost their
effectiveness

Hal
-----Original Message-----
From: dkern@juno.com [mailto:dkern@juno.com]
Sent: Friday, June 12, 1998 4:49 PM
To: alt-photo-process-l@skyway.usask.ca
Subject: Storage unit materials

A couple of months ago there was some discussion on the list regarding
plans for making one's own storage units. There was a discussion of
materials to use and I, along with some others, stressed that
wood--especially plywood and particle board were potentially very
damaging. Today I discovered this post on the Conservation Dist List and
I thought I'd share it with the alt-photo-l in case anyone is still
contemplating their plans.

David Kern

>Date: 11 Jun 98
>From: Paul Storch <paul.storch@mnhs.org>
>Subject: Shelving

>Nancy J. Cyr <ncyr@che2.che.umn.edu> writes

>>I am writing the specifications for laminated shelving to be used as
>>additional shelving in some 25 year old laminated cabinets. I know
>>exterior grade plywood is supposed to be low in formaldehyde and
>>should be used instead of particle board, but what about adhesives?

>Medite II, manufactured by the Medex Corp., is exterior grade
>particle board that utilizes a phenol-formaldehyde adhesive as the
>binder. It meets conservation specifications. The general
>specification for plywood or oriented strand board (OSB) is:
>exterior grade, American Plywood Association (APA) approved.

>Having said that about the spec for phenol-formaldehyde, which is only
>the glue and/or binder for the layers or particles, there is still the
>issue of the off-gassing of acetic acid and other carbonyl compounds
>from the wood fibers themselves that has to be dealt with. The exposed
>surfaces of the shelving boards still need to be coated or covered to
>prevent these harmful VOC's from adding to the deterioration of metals,
>carbonate-based objects, textiles, paper, and other materials. The
>common misconception with wood-based board materials is that if the
>potential formaldehyde problem is solved, then the materials are inert,
>which is far from the case.

>Pam Hatchfield has done extensive testing and research on this issue and
>has found that Camger Water-borne Urethane coating is the best barrier
>for museum storage applications. Keep in mind that no lacquer type
>resin coating is a 100% barrier to VOC's or moisture, but this product,
>if applied properly in two complete coats according to instructions and
>allowed to cure completely, will provide adequate protection. The other
>alternative is to completely cover the exposed surfaces and edges of the
>boards with a barrier film such as MarvelSeal. A film such as Corrosion
>Intercept, which is not a barrier film but acts as a passive "sink" for
>pollutant molecules, can be used in conjunction with the coated
>shelving.

>Paul S. Storch
>Objects Conservator
>John and Martha Daniels Objects Conservation Laboratory (JMD-OCL)
>B-109.1, Minnesota History Center
>345 Kellogg Blvd West
>St. Paul, MN 55102-1906
>612-297-5774
>Fax: 612-297-2967

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