Case studies using Pemulen emulsion


At Shelburne Museum, the working method has been as follows:

  1. Emulsion is shaken in the jar prior to use and then a small amount is decanted into an open container.
  2. Using a small soft flat brush, emulsion is brushed on to the surface to be cleaned and gently agitated using the brush.
  3. Once the emulsion appears to be colored with grime, it is wiped from the surface using cotton wadding or cotton swabs.
  4. The area cleaned is then cleared with deionized water on cotton swabs.

Case study 1

Dentzel carousel panel (oil on canvas) depicting Uncle Sam and Spain

FC-7.66, Collection of Shelburne Museum

2007062423UncleSam.pdf

This was one of the first objects where we tested the use of a Pemulen/benzyl alcohol emulsion.  The painting on canvas had an uneven and very yellow varnish on the surface which was somewhat soluble in acetone.  Cleaning with acetone on cotton swabs was uneven, however.  While the Pemulen emulsion was effective in some areas, some paint colors were sensitive to water, and so other cleaning solutions were used in those areas.

 

Case study 2

Dentzel carousel panel (oil on canvas) depicting a woman walking a dog

FC-7.62, Collection of Shelburne Museum

2008062424womanwalkingdog.pdf

This was another one of the first objects where we tested the use of a Pemulen/benzyl alcohol emulsion. Like the Uncle Sam carousel panel, this painting also had a very uneven and yellowed surface coating.  Additionally, the front and back of the canvas had been splattered with black machine oil. The oil on the back of the canvas had migrated through the paint and varnish to the surface of the painting, appearing as solid black dots.The thick black oil was thinned from the back to the canvas before working from the front to remove the oil that had penetrated through.  Examination of the paint showed that the oil had migrated through fissures in the oil paint, much in the way filliform corrosion grows through micropores in coatings on metal. Both Carbopol gels and Pemulen emulsions were tested for cleaning the front of the painting.  Bulking Carbopol gels with inert absorbtion materials (cellulose powder, Attapulus clay) were also tested as a possible poultice material for removing machine oil from the canvas back.

 

Case study 3

Wood train (oil paint on wood)

1977-45, Collection of Shelburne Museum

2008052513modeltrain.pdf

The painted wood train had a grimy layer of wax on top of the glossy black paint.  While an application of petroleum distallates on cotton swabs followed by 2 % ammonium citrate in deionized water was slowly effective at removing the grimy wax, petroleum distallates emulsified into a Pemulen gel made with TEA and 2% TRIS was more effective, working more quickly and evenly than the two step system of using petroleum distallates followed by ammonium citrate.