I did experiments with bitumen and i will try to explain what I observed. The main reason to use it is for properties to make the wood look like older, to give more aging to the wood. This cannot be compare to paint because it does not cover completely. It would be more on the side of dyes. One of the advantage of this powder, is depending of the amount you add, you will get different results. Asphalt can be mixed with many components depending of the look we want to produce.
Beeswax Slows drying time, soften the color and more transparent. Mixing it with the
bitumen allows beewax molecules to bind and make the asphalt more neutral
paraffin: help beewax or could be white wax candle
asphalt: Was used by the egyptiens for embalming Oil suluble
pine resin: Gives plastic properties and can form a varnish if mixed with alcool
natural soap: probably for the oils in the soap
turpentine: Fluidity and solubility of the mix
siccative: shorter drying time, max 10% of total mix.
My preference is to mix it with tung oil, that I prefer to other oils. When dry, this oil does not produce a shiny finish which is particuliary visible when you use a flash on the camera. At first, I used only tung oil which gives a look of 50 years in aging the wood. Later I did experiment by adding asphalt.
In small quantities, it will act as a dye but clearer, not as dark as a dye can go. In the mixing, when you exceed his property of absorption by dilution, asphalt powder will precipitate in the bottom of the container and if you use this mix, it will produce on the wood a general finish plus different spots which can look like dirt caused by time.
I remember the first time I saw the utilisation of bitumen. It was on a 74 gun ship made by A French named Fichant. By using bitumen, he made his model look like 150 years older than it really was.
Edited by Gaetan Bordeleau, 17 October 2014 - 02:09 PM.