Search This Blog

Saturday, February 22, 2020

Developmental Oil Paint/ Mixed Mediums

Commerical oil-based paint blended with 20% (m/v) dammar resin in  C16-C20 beta-brached alcohols. These are commercially-availabler so-called 'guerbet alcohols" which are biodegradable.

Sassol North America, fo0r example, sells these odor-free alcohols.
The paint has been applied to bristol paper with no undercoat.

Friday, February 21, 2020

Developmental Oil-Based Paint

We have taken up  dammar resin (20% m/v) in castor oil with some oil of citrus ( limonene) added.
Commercial oil-based paint was added and stirred to homogeneity.

The paint was applied to bristol paper with no gesso undercoat.  The paint was dry to the touch in one hour at 20 deg.C.

Tuesday, February 18, 2020

Developmental Water-Based Polyurethane Paints

We are developing water-based polyurethane paints with various dyes,

One was subjected to 1.5 hrs. of very close-range long wavelength UV with 1/2 the area exposed to UV and the other half covererd.

We found no fading occured in this time frame.

Below is a swatch of three various commerical dyes with the water-based polyurethane binder on bristol paper:

Water-based polyurethane emulsion is more expensive than the acrylics , but the former is bio-degradable.

Sunday, February 16, 2020

The Guitar: Water-Based Polyurethane Paint Study

I am developing water-based polyurethane paints which, although more expensive, provides a paint formulation which is environmentally healthier. The acrylics are not biodegradable and the polyurethane is known to be broken down by microbes. This may be easier on the environment with paint waste discharge.

(A test of polyurethane paint formulations. The paint dries quickly like the acrylics. Some soft pastels have also been used in this mixed mediums study.

Dammar Gum (Resin) Green Varnish Preparation

Dammar gum , from India and Near Asia, has been used as a varnish for oil paintings.
It is traditionally prpared by dissolving the gum in turpentine solvent.

In my research, I have found that Dammar gum (light yellow) can be dissolved ( 10-20% m/v) in oil of citrus ( -limonene) at 90 deg C in 2-3 minutes with light stirring. The cooled solution is then gravity filtered to provide a colorless varnish. Without filtration, the dried surface will have a yellow coloration.

Many oil painters are working in very limited space and the varnish, prpared this way, has a pleasant smell and turpentine fumes are avoided.

I have used a heat gun to dry the varnish ( applied to bristol paper) in minutes.

The bottom image reveals the yellow dried varnish film if filtering is not carried out. The barnd of Dammar resin I used is noted in the top image.

I hope oil painters will consider this healthier approach in their work!