JAIC 1988, Volume 27, Number 1, Article 2 (pp. 32 to 37)
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Journal of the American Institute for Conservation
JAIC 1988, Volume 27, Number 1, Article 2 (pp. 32 to 37)


Fonda G. Thomsen


Given the relatively low melting point of polyester resin (500 F) and its tendancy to flow when melted, a search was started for a way to melt and seal the edge of the Stablitex fabric to avoid the fraying of cut edges. With the assistance of our metals conservator, a hot wire pen was manufactured and connected to a rheostat. This worked well in “cutting” the fabric. The rheostat allowed for the adjustment of the temperature of the pen tip to get the desired degree of melt.

The desired degree of melt was determined by studying the melted edge under the microscope. Too much heat caused a carbonization of the fibers with almost no flow. The temperature was lowered until there was jsut enough heat to melt the fibers and create a flow of the polyester. This melt bound the woven plies together, giving an edge that wouldn't unravel. The actual temperature at which this melt took place was not quantified because it is variable depending upon the heat transfer properties of the surrounding surfaces. It seems reasonable that it was just above the 500 degree melting point of the material.

Having accomplished a suitable sealed edge, work was done to expand the application of the basic technique. Taking a variety of objects, treatments were explored to determine if Stabiltex could be incorporated to provide a more satisfactory treatment. The hot melt technique was then adapted to try to meet that need.

It soon became apparent that the hot melt cutting tool was very useful for a variety of techniques. A search was conducted for commercially available equipment that would do the job. A wax carving tool that had five different shaped tips and a variable temperature in a suitable range was purchased. It performed as well as the home-made model.

Copyright 1988 American Institute for Conservation of Historic and Artistic Works