Volume 16, Number 1, Jan 1994, pp.26-27

Technical Exchange

Chemical Sponges

The Quality Rubber Company makes an Industrial Cleaning Sponge that works to remove soot. I've dealt with Tom Savarese, the National Sales Manager, who is in Sedalia, Missouri. The company is headquartered in Seminole, Florida (813-397-8802). Call and ask for a sample.

Filmoplast P-90 Effects

As is well known by book, paper, and photo conservators, the pressure-sensitive tape Filmoplast P-90 becomes progressively more difficult to remove as the adhesive ages. I have come across an additional effect of the tape during a recent treatment of a work by Helen Frankenthaler (Ochre Dust, 24-3/8 x 33 inches, 1987). The print is listed in the book Helen Frankenthaler: Prints by Ruth Fine (No. 63 in this National Gallery of Art exhibition catalog), as a four-color lithograph and aquatint on Rives BFK paper, printed by Tyler Graphics, Ltd. of Mt. Kisco, New York. A call to the printer revealed that "standard" printing inks in black, blue black, tan and yellow ochre were used.

The film appeared to have been framed/mounted only once since its purchase, using V-hinges of Filmoplast around and about 1/2 inch from the perimeter of the paper edge. The print was hinged onto an archival-quality backboard, etc. The yellow ochre/tan inks in areas corresponding to the Filmoplast tapes on the reverse are now a distinct greenish ochre, while the remainder of the large ochre field of color is, by contrast, much more "red," or what one might usually expect in an ochre.

In the course of further investigating this effect, I would appreciate correspondence from other conservators or framers who have had similar experiences with naturally aged Filmoplast P-90 tape.

Modifications to Home Freezers for Pest Control

The SPNHC Newsletter, Vol. 7., Number 2, August 1993 carries an excellent note by Ann Pinzl on how she was able to achieve -20¢ F (-29¢ C) in ambient air of 40-85¢ F, using a Westinghouse chest freezer model No. FC083TW (R-12 system).

Her local refrigeration technicians bypassed the cold control, increased condenser capacity, added a suction line accumulator to stop liquid refrigerant from returning to the compressor, and added a condenser fan to maintain constant and consistent temperatures. Ann Pinzl, Nevada State Museum, Capitol Complex, Carson City, NV 89710-0001 tel (426) 586-5593.

Faced with an infestation emergency, I purchased a GE chest freezer FH22DS, inserted the probe from an indoor/outdoor thermometer (Micronta 63-854, about $10.95 from Radio Shack) (thanks to Tom Strang of CCI for the idea) and was delighted to find that I achieved temperatures of -32¢ C. I noticed a small frost pimple on the outside, however, and called 1-800-GE-CARES for advice. They sent a new freezer the next day (!); unhappily, it wouldn't go below -5¢ F. Since my maverick freezer was now lost in the system, I consulted my local appliance repairman, who explained that freezers are designed to work at -10¢ to +10¢ F to prevent freezer burn. When I explained my need for at least -30¢ C (constant), he cheerfully pulled off the rear control panel, pulled two pins to bypass the thermostat (and explained how to replace them if I needed warrantee service), and opined that I should be able to run the freezer for 3-4 months at a time without damage to it. It stays constant at -35.1° C.

Cool Tools

ExTech Instruments (335 Bear Hill Road, d, Waltham MA 02154; 617- 890-7440) provides inexpensive meters for temperature, RH, pH, conductivity and a multimeter light reading adaptor; possibly their neatest item is a small battery/AC electronic scale with auto zero, tare, measuring grams or ounces in ranges of 1-2000 g or .1-225 g, accuracy 0.4% plus/minus 1 1 digit, from $89. Thanks to Bill Lull of Garrison Lull for the source.

Caddies

Monica Jaworski is selling Swiss watch part boxes for pigment palettes of molded plastic with 23 lidded wells about 5/8" deep. The case is approximately 10" x 4.5 x 1 and has a hinged lid and spaces between the wells that allow for packing small tools and brushes. The empty box is $ 7.50, the case in plastic is $19.95, and with aluminum wells $42.95. Contact Monica Jaworski at PO Box 60467, San Diego, CA 92166, 619-231-4019.

Less elegant but cheap is the Bead-Caddy: molded translucent plastic wells in single or double rows of 6, with screw-on tops (labelable), which stack. Available in craft section of cheap stores like AMES, or from Dal-Craft Inc, PO Box 61, Tucker GA 30085. Ask for free catalog.

Microscope for Sale

Stereobinocular surgical microscope for sale. This microscope is new and has only been used for evaluation purposes. Freestanding, heavy duty, high optical quality surgical microscope with build in lighting and interchangeable 10x and 25x eyepieces. The mounting system allows virtually full triaxial movement with 5 different magnifications. 7" working distance; 6foot stand allows for 3 feet of vertical adjustment, and the extendible elbow/arms allow for work up to 30" away from the main stand. The microscope is very well made by the Polish Optical Institute and is only being sold because two were shipped instead of the one requested. Completely assembled and ready to go. Price is excellent at $5900. Persons with a serious interest should call Duane Chartier at ConservArt Associates (310) 391-3537.

Mini Attachments for your Vacuum

Recently admired at the Cincinnati Art Museum lab was a gift from Jim Bernstein: a hose plus 5 dandy tools, available from Improvements, 4944 Commerce Parkway, Cleveland OH 44128; 1-800- 642-2112.

A similar but less sturdy-looking version is advertised for $8 from Starcrest of California, 19465 Brennan Ave, Perris CA 92599 ; 909-657-2793.

NOTE: blowing or sucking air can generate a static charge which can fry the motherboard of a computer; you may prefer to use these vacuums for art, not computers; never mind what it says on the package.

Skin-Care Tip for Chapped Hands from the Leather Conservator

Recently discovered at Mike's Hardware Store in Marksville, Louisiana is Horseman's Dream Veterinary Cream. Intended to prevent skin scarring on show horses and dogs, this cream contains Allantoin, aloe vera extract, lanolin, wheat germ oil, rice bran oil, vitamins E,A, and D, lanolin alcohol, sesame oil, moisturizers and humectants. Fabulous!!!! Horseman's Dream Division, SportCare International, Inc, Fort Worth, Texas 76126 or try your local veterinary supply. (While you're there, Proctor and Gamble Shur-Gain Animal Shampoo is Orvus in other guise...) Lisa Mibach

Prize Winner

Stephen Bonadies wins the TechEx Elegant Adaptation prize for this issue, for creating soft canvas sandbag snakes from Brookstone white canvas soaker hose.

Computer Programs for Boxmaking

At Princeton we use a spreadsheet program into which we enter the three dimensions of the book that we want boxed. The program then calculates the dimensions of the boards and provides measurements for the folds. The program itself is fairly straight forward. It is just a matter of inputting the simple formulas that you use now for making a box. You have to figure the dimension of the book, plus the thickness of the board and so on. Once you have the program made you will need to fine tune it so that you get the box to fit right. Our program has proven to be a big time saver.

The most sophisticated program I have seen for boxmaking is used at New York Public Library. It is a Mac based system that provides box dimensions and labels for the box--very impressive.

Reprinted courtesy of the Conservation DistList

Ed. notes: 1. Ralph Roessler Paper Technologies, Inc. <72537.3447@compuserve.com> clarifies that this program may be by

Mark Reeves
New York Public Library
5th Ave & 42nd St
New York, NY 10018

Readers may also be interested in Bob Futernick's program using a Wacom pressure-sensitive tablet for calculating sizes for mat-cutting. Perhaps we can ask Bob to contribute a description for a future issue.

Silverfish Traps

At the University of Florida, we've found that Boric acid--besides being messy, requiring the pest to traipse through it without apparent incentive--is rendered ineffective, over time, by the humidity in which Silverfish thrive. ... So not only is it messy, unattractive, and physical separated from infested materials, but it also has to be replaced relatively often.

Our Pest Control Division urges us to use silica gel as well. Within enclosed spaces, e.g., map cases, with low rates of air exchange, this seems to work well, reducing humidity in the case and controlling silverfish populations. The interval between replacement is longer for silica than boric acid, and silica can be "reconditioned" (though not easily) for effective reuse. (Given our humidity problems and appropriate apportionment of silica, there seems little danger that we will lower relative humidity below optimal levels for storage of the paper or photographic materials.)

We have also determined that use of silica and other humidity controls merely slow rates of population growth without also reducing and maintaining low(ered) temperatures. Temperature level, however, depends upon the type of Silverfish infestation. Lepisma saccharina, the most common, the actual "silverfish", requires incubation temperatures above 72 degrees F (22 degrees C). Other species, particularly those identified in California, i.e., Ctenolepisma longicaudata, Ctenolepisma urbana, and Ctenolepisma quadriseriata, require higher incubation temperatures. In one of our infested collections, we attempted to maintain temperatures between 65 and 70 degrees F while also dehumidifying for a period of two weeks.

Our Pest Control Division also suggested use of simple home-made traps. The traps, described below, seem to work wonderfully, but may also represent a source of food for other insects which can escape them. The trap is a small glass with smooth sides (a small guide ramp up the outside, i.e., a piece of paper, wrapped around the outside) and partially filled with flour. (I have also mixed boric acid in my traps at home to kill insects which might otherwise be able to escape. I imagine a mixture with silica powder might starve rather than poison the insects.) Assuming your silverfish are attracted, and capture entire populations traps would have to be tended and remain with infested materials for 3 to 4 months minimum.

Queries

Dale Kronkright is very interested in talking with sculpture conservators who have had experiences with application and removal of layered wax-resin coatings on outdoor sculpture.

He is also interested in talking with anyone who knows of published materials on the production or history of regional Mexican "lacquer" objects.

Next Issue

Next issue will feature products to reduce out-gassing in exhibit and storage construction: HDO plywood, sealants, and gaskets. Send your suggestions for this and other topics to Lisa Mibach, MPO Box 623, Oberlin, OH 44074-0623, or (preferably) via email at Perygrine@aol.com.