Volume 19, Number 2 .... May 1997

Technical Exchange

Dean Yoder
Column Editor

Solux® MR16

Conservators have long searched for a cost effective artificial light source which can accurately reproduce daylight across the visible spectrum. The quot;daylight" may have finally arrived.

Solux is an MR16 format, 12 Volt, 50 watt tungsten-halogen lamp. It was developed to provide accurate color rendition with a uniform beam pattern, extremely low UV emission (8.3 microwatts/lumen), and low infra-red output. The cost is about $12.00 per lamp. It does require a 12 Volt transformer, however a 600 watt transformer provides enough current for twelve Solux lamps, and can be obtained from wholesale outdoor lighting supply companies for about $110.00.

According to Ulrich Birkmaier, associate paintings conservator at the deYoung Museum, the Solux bulb is the closest to sunlight that he's ever seen among artificial light sources. The Fine Arts Museum of San Francisco has been using one 50 watt lamp with a 24 degree beam spread as a light source for working on small paintings. This lamp has a built-in transformer that can be screwed into a regular 120 volt socket. It costs about $100.00. Larger paintings are illuminated with a home made assembly, comprised of four lamps and commonly available fixtures.

The Solux lamp is being used in many diverse applications, including: jewelry displays, light therapy, and color matching in paint stores, to name a few. The inventor, Kevin McGuire, was particularly gratified to hear that conservators were using Solux, since the illumination of artwork and color matching were the driving force behind this new lamp. And, of further interest, a Par38 daylight lamp is currently being developed for distribution later this year.

Technical Specifications:
Format: 12 Volt, MR16 with color glass
Wattage: 50 Watts
Average Life: 3,000 hours
Color Temp: 4700K
CRI(Color Rendering Index): 99+
Beam Spreads:12, 24, and 38 degrees

Solux is a product of Wiko Ltd., and the CA distributor is TRAC sales company. Contact: Jim Hudspeth (415) 571-7200.

Website for Wiko: WIKOLAMPS@aol.com
Technical Information: kevlight@vivanet.com

Ulrick Birkmaier can be reached at: ubirkmaier@famsf.org

Additives for sturgeon glue

An excerpt taken from the Conservation Distlist: February 4

Query:
When using sturgeon glue for consolidating paint flakes we have been using ethanol for reducing the surface tensions. We are interested to know if this can cause any chemical reactions, i.e. influence the reversibility of the glue film.

Reply:
In 1991, we looked at adding garlic juice, glycerin and fumed silica to Sturgeon Glue to improve flexibility. This was done in conjunction with a treatment of a Boulle Clock that the Canadian Conservation Institute furniture lab was conserving at the time.

It was found that all additives improved flexibility at the concentrations tested but little was known about the long term effects of adding such compounds. It was argued that possibly garlic juice might evaporate with time and the sturgeon glue would lose its flexibility. One author argued that fumed silica might interfere with the natural hydrogen bonding of the adhesive to the substrate. To avoid these outcomes, only glycerin (5%) was added to the glue for the treatment.

This report is available from CCI ($10 Canadian for Canadians; $20 Canadian for International clients; these prices include postage).

We have not tested ethanol or Photo-Flo or for that matter any wetting agents on Sturgeon Glue.

For further information contact: Jane Down, Senior Con. Scientist, CCI.