But, the wood products are in all built environments, as well as many
cupboards and display cases. Wouldn't it be a more real-world test? Of
course, I will defer to you as the metals expert!
Marc
American Conservation Consortium, Ltd.
4 Rockville Road
Broad Brook, CT 06016
www.conservator.com
860-386-6058
*Collections Preservation Consultation
*Conservation Assessments & Surveys
*Environmental Monitoring & Low-Tech Control
*Moisture Management Solutions
*Collections in Historic Structures
*Collections Care Grant Preparation
*Conservation Treatment of:
Furniture
Painted Wood
Horse-Drawn Vehicles
Architectural Interiors
Marc A. Williams, President
MS in Art Conservation, Winterthur Museum Program
Former Chief Wooden Object Conservator, Smithsonian Institution
Fellow, American Institute for Conservation (AIC)
----- Original Message -----
From: "David Harvey" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, October 02, 2007 1:47 PM
Subject: Re: [MUSEUM-L] Need help tarnishing silver
> Marc,
>
> I would lean away from using plywood or wood products in association
> with this. The tarnish and corrosion of metals by the organic acids in
> woods is a different mechanism from sulphide corrosion and thus might
> produce different results than an experiment using a box/container of
> an inert material with sulphur. The various silver cloths are
> speciifcally developed to reduce sulphide corrosion and thus may not
> work as effectively with the acids outgassed by woods.
>
> Cheers!
> Dave
>
> David Harvey
> Conservator
> Los Angeles, CA
>
> On 10/2/07, Marc A Williams <[log in to unmask]> wrote:
>>
>>
>> How interesting how one thread leads into another! The following link is
>> about how to clean up spilled mercury, a question from a week ago or so.
>> It
>> also states that powdered sulphur can be used to assist in this process
>> and
>> that it is available from garden supply houses or pharmacies.
>> http://www.des.state.nh.us/factsheets/hw/hw-15.htm
>>
>> http://www.somaluna.com/product.asp?p=180 Link for
>> purchase of powdered sulphur - many others available in Google search.
>> Small town or large city, everything is available over the internet.
>>
>> If you want to accelerate the experiment, I would suggest that you heat
>> it
>> up. Place the items in a small oven (such as the inexpensive tabletop
>> ones
>> - NOT microwave). I wouldn't use a stove oven, as the time period could
>> be
>> fairly long, and the energy costs would be high. You can also create
>> your
>> own by making a small box (I would use plywood) and placing an
>> incandescent
>> light bulb inside. You probably can use the cooler box for your oven if
>> it
>> is not flammable. You can change the wattage of the bulb to get the
>> desired
>> temperature. Be sure that the bulb does not directly contact anything
>> flammable. It shouldn't get hot enough to ignite the wood if you stay
>> below
>> 100 watts, but check this out carefully if you have wood contact.
>> Whether
>> you make your own oven or use a countertop one, insert a digital
>> thermometer
>> into the oven - one of those with a long corded sensor for
>> outdoor temperatures (keep the thermometer body outside the oven) - they
>> are
>> about $8 at Home Depot, Wal-Mart or the like. Put the sensor near the
>> silver samples. I would suggest holding the temperature at 125-150
>> degrees
>> F. Higher will move things along faster, but may also cause chemical
>> reactions to occur that would not at lower temperatures, thereby reducing
>> the validity of the experiment. Place the items as high in the oven as
>> possible - the floor of the oven can be considerably cooler than the top.
>>
>> I would suggest adding a few silver samples to your experiment. I would
>> wrap one silver sample is a clean, freshly washed cotton cloth (use a
>> detergent without perfumes or additives), as the reduced air circulation
>> of
>> cloth alone may have an effect. I would place another silver sample in a
>> polyethylene Ziploc bag, freezer weight, nothing special, just from the
>> grocery or discount store. These are often recommended as an easy,
>> inexpensive way to protect items in storage. You probably should have
>> another sample as a control that is not inside the container with the
>> others. This could be in a Ziploc bag in the freezer to inhibit any
>> tarnishing. You may actually have tarnishing on your control in the
>> cooler,
>> but it just doesn't show since it is even and slight. This will give you
>> something to compare it to. If you add these additional samples, you
>> will
>> need to polish all the samples again so that you start with the same
>> amount
>> of time. Then, place them in their respective protective wraps.
>>
>> Cutting up the rubber bands would increase their surface area. The
>> smaller
>> the pieces, the better (I wonder what would happen if you put them in a
>> blender? If you try it, just do a single one in case it causes a
>> problem,
>> you can stop immediately without damage to the blender - I'd use the
>> pulse
>> button.). You can also use powdered rubber eraser, which can be
>> purchased
>> already powdered or you can chop it up yourself (be sure it is actually
>> rubber, not plastic). Powdered sulphur also may work - no reason you
>> can't
>> use both. You may get some odors from the oven, so enjoy them, or do
>> this
>> where the smell is not a problem. You can also consider wood sawdust or
>> shavings, especially oak. Hand planing an oak lumber scrap will easily
>> produce shavings.
>>
>> Just out of curiosity, did the polish you used have a tarnish inhibitor
>> in
>> it? That might explain why nothing has happened yet.
>>
>> Please report back on this, as I'm sure many of us would like to know
>> your
>> results.
>>
>> Marc
>>
>> American Conservation Consortium, Ltd.
>> 4 Rockville Road
>> Broad Brook, CT 06016
>> www.conservator.com
>> 860-386-6058
>>
>> *Collections Preservation Consultation
>> *Conservation Assessments & Surveys
>> *Environmental Monitoring & Low-Tech Control
>> *Moisture Management Solutions
>> *Collections in Historic Structures
>> *Collections Care Grant Preparation
>> *Conservation Treatment of:
>> Furniture
>> Painted Wood
>> Horse-Drawn Vehicles
>> Architectural Interiors
>>
>> Marc A. Williams, President
>> MS in Art Conservation, Winterthur Museum Program
>> Former Chief Wooden Object Conservator, Smithsonian Institution
>> Fellow, American Institute for Conservation (AIC)
>>
>>
>>
>> ----- Original Message -----
>> From: Melissa Thompson
>> To: [log in to unmask]
>>
>> Sent: Tuesday, October 02, 2007 9:28 AM
>> Subject: Re: [MUSEUM-L] Need help tarnishing silver
>>
>>
>> We are not using the cooler to actually cool the silver, just as an
>> enclosed
>> environment. I guess we could have used a tupperware tub too, but the
>> cooler
>> was more accessible. We are in a small town (pop. 8000) and do not have
>> access to much. I don't know how we would go about acquiring powdered
>> sulpher. Would cut up rubber band work for the shredded rubber?
>>
>> Melissa Thompson
>>
>>
>> On 10/1/07, Marc A Williams <[log in to unmask]> wrote:
>> >
>> >
>> > First of all, use a wooden box, perhaps fresh plywood, if you are using
>> > a
>> box. Why the cooler? This will really slow down the processes. Sulphur
>> is
>> available as an element in powdered form. However, it may not volatize
>> quickly. Shredded rubber may be a better solution. The finer the
>> particulation, the greater the surface area, and the more quickly it can
>> get
>> into the air. Heating any of these will speed the process (even a light
>> bulb will do), but I'm unclear if the cooler will negate the effect. If
>> this is a preservation experiment, it would be better to do it at
>> elevated
>> temperature, rather than lowered. Any effects can be translated to lower
>> temperature, subject to the rule of thumb that processes slow in half for
>> every 10 degree C (18 degree F) temperature drop. Thus,
>> oxidation/corrosion
>> at 35 degrees F will be roughly 32 times slower than at 125 degrees F
>> (or,
>> at 125 degrees F, they will be 32 times faster than at 35 F). This may
>> be
>> your experimental design problem. Please give us a bit more information.
>> >
>> > Marc
>> >
>> > American Conservation Consortium, Ltd.
>> > 4 Rockville Road
>> > Broad Brook, CT 06016
>> > www.conservator.com
>> > 860-386-6058
>> >
>> > *Collections Preservation Consultation
>> > *Conservation Assessments & Surveys
>> > *Environmental Monitoring & Low-Tech Control
>> > *Moisture Management Solutions
>> > *Collections in Historic Structures
>> > *Collections Care Grant Preparation
>> > *Conservation Treatment of:
>> > Furniture
>> > Painted Wood
>> > Horse-Drawn Vehicles
>> > Architectural Interiors
>> >
>> > Marc A. Williams, President
>> > MS in Art Conservation, Winterthur Museum Program
>> > Former Chief Wooden Object Conservator, Smithsonian Institution
>> > Fellow, American Institute for Conservation (AIC)
>> >
>> >
>> >
>> >
>> > ----- Original Message -----
>> > From: Melissa Thompson
>> > To: [log in to unmask]
>> > Sent: Monday, October 01, 2007 5:38 PM
>> > Subject: [MUSEUM-L] Need help tarnishing silver
>> >
>> >
>> >
>> >
>> > We are conducting an experiment to determine whether or not the price
>> > of
>> silver cloth is relative to its tarnish prevention abilities. We have
>> three
>> pieces of newly polished non-museum silver. One is wrapped in the
>> expensive
>> Pacific Silver, another is wrapped in the cheap Joann Fabric silver
>> cloth,
>> and the third is the control piece not wrapped in anything. We want the
>> pieces to tarnish and are trying to accelerate the process.
>> >
>> > The conservator we have consulted suggested putting the pieces in a box
>> > to
>> control the air that has access to the objects. We are using a cooler.
>> She
>> told us that sulpher is a tarnishing agent and we have to introduce more
>> sulpher into the air. Her suggestions were egg yolks, moist matches, and
>> rubber bands. These have not tarnished the silver at all and we have
>> been
>> working on this for two months. Does anyone have suggestions on how to
>> quickly tarnish silver or another way to test this hypothesis? Has
>> anyone
>> ever done anything similar to this?
>> >
>> >
>> >
>> > Melissa Thompson
>> >
>> > Collections Assistant
>> >
>> > Vesterheim Nowegian-American Museum
>> >
>> > 523 W. Water Street
>> >
>> > Decorah, IA 52101
>> >
>> > 563-382-9681 x242
>> >
>> > www.vesterheim.org
>> >
>> > [log in to unmask]
>> >
>> >
>> >
>> >
>> >
>> >
>> =========================================================
>> Important Subscriber Information:
>> >
>> > The Museum-L FAQ file is located at
>> http://www.finalchapter.com/museum-l-faq/ . You may obtain
>> detailed information about the listserv commands by sending a one line
>> e-mail message to [log in to unmask] . The body of the message
>> should read "help" (without the quotes).
>> >
>> > If you decide to leave Museum-L, please send a one line e-mail message
>> > to
>> [log in to unmask] . The body of the message should read
>> "Signoff
>> Museum-L" (without the quotes).
>> >
>> >
>> >
>> >
>> >
>> >
>> > =========================================================
>> Important Subscriber Information:
>> >
>> > The Museum-L FAQ file is located at
>> http://www.finalchapter.com/museum-l-faq/ . You may obtain
>> detailed information about the listserv commands by sending a one line
>> e-mail message to [log in to unmask] . The body of the message
>> should read "help" (without the quotes).
>> >
>> > If you decide to leave Museum-L, please send a one line e-mail message
>> > to
>> [log in to unmask] . The body of the message should read
>> "Signoff
>> Museum-L" (without the quotes).
>> >
>> >
>> >
>> >
>> >
>> >
>>
>> =========================================================
>> Important Subscriber Information:
>>
>> The Museum-L FAQ file is located at
>> http://www.finalchapter.com/museum-l-faq/ . You may obtain
>> detailed information about the listserv commands by sending a one line
>> e-mail message to [log in to unmask] . The body of the message
>> should read "help" (without the quotes).
>>
>> If you decide to leave Museum-L, please send a one line e-mail message to
>> [log in to unmask] . The body of the message should read
>> "Signoff
>> Museum-L" (without the quotes).
>>
>> =========================================================
>> Important Subscriber Information:
>>
>> The Museum-L FAQ file is located at
>> http://www.finalchapter.com/museum-l-faq/ . You may obtain
>> detailed information about the listserv commands by sending a one line
>> e-mail message to [log in to unmask] . The body of the message
>> should read "help" (without the quotes).
>>
>> If you decide to leave Museum-L, please send a one line e-mail message
>> to
>> [log in to unmask] . The body of the message should read
>> "Signoff
>> Museum-L" (without the quotes).
>>
>>
>
> =========================================================
> Important Subscriber Information:
>
> The Museum-L FAQ file is located at
> http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed
> information about the listserv commands by sending a one line e-mail
> message to [log in to unmask] . The body of the message should
> read "help" (without the quotes).
>
> If you decide to leave Museum-L, please send a one line e-mail message to
> [log in to unmask] . The body of the message should read
> "Signoff Museum-L" (without the quotes).
>
>
=========================================================
Important Subscriber Information:
The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes).
If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).
|
