A few questions about wax mediums.
1. Most wax mediums have some sort of resin and solvent. Does anyone know if Renaissance Wax contains a resin (its ingredients are listed as microcrystalline waxes & mineral spirits)? If not, what causes it to harden; is it just the inherent hardness of the mix of petroleum based waxes in it, once the solvent content has evaporated?
2. Dorland’s Wax Medium is made from beeswax, paraffin, microcrystalline wax, dammar; it does not list its solvent content in the ingredient list, just says “can be thinned with turpentine or mineral spirits”. Yet other places on the web say it can be thinned with OMS. Anyone know it’s solvent content?
3. Are microcrystalline waxes (no color, harder) preferrable to bees wax, or are they equally good?
4. Can solvent-based wax mediums be applied on top of water-based synthetic polymer isolators (such as a PVA, GAC 500, etc)?
5. I presume that for a wax medium to go on top of a solvent-based isolator, it must contain a different solvent from whatever went into the isolating coat; otherwise applying the wax medium would dissovle the underlying isolator – yes?
6. Has anyone tried the Williamsburg wax medium, which is solvent free, as a finishing layer? If so, any thoughts on its appearance, drying time, etc.?
7. Finally, if George O’Hanlon at Natural Pigmetns could clarify the practical differences between his two wax mediums (Rublev Wax Medium [beeswax, dammar, odorless mineral spirits – Rublesol, I presume?] and Conservar Wax Medium [microcrystalline wax, aldehyde resin, mineral spirits], that would be most helpful.
Thanks! Koo Schadler
Williamsburg Wax Medium is fully explained in the Just Paint article: https://justpaint.org/williamsburg-wax-medium/
The two different wax pastes made by Natural Pigments, Rublev Colours Wax Medium and Conservar Wax are used for different applications.
Conservar Wax is recommended as a final finish of a painting, since the microcrystalline wax and aldehyde resin are more stable than dammar.
Rublev Colours Wax Medium may be used as an ammendment to oil paint, although we highiy recommend not adding large amounts to oil paint.
While dammar is not soluble in odorless mineral spirits it is soluble in wax and odorless mineral spirits when heated to 80º C.
I am going to let others respond to most of your questions on this post as I have little experience with wax pastes, especially commercial ones.
A couple of things, though. Dammar is insoluble in OMS so that does not seem an appropriate solvent for Doland’s Wax Medium.
PVA resins are soluble in ethanol, toluene, and acetone. Is can be disturbed but not dissolved in xylene. It is often a good choice for interlayering with a resin varnish soluble in OMS or turpentine soluble resins.
Applying a resin dissolved wax paster containing a solvent that is the same as that used for a varnish can result in dissolving or disturbing the lower layer.
Hopefully others will weigh in on the other questions.
EDIT George posted while I was composing my response. Ha. Thanks George.
I found a jar of Dorland’s Wax Medium in my studio. The label lists ingredients as “mineral spirits, paraffin wax, demar [sic] resin, micro-crystalline wax, bees wax & ozokerite wax”. The label also says to thin with “odorless mineral spirits”. George’s note that dammar is soluble in wax and odorless mineral spirits when heated to 80º C. explains this discrepency, yes? I presume that heating occurs in the making of the medium (not during its use by a painter). The consequence of heating in the manufacturing process is that the medium is henceforth soluble in OMS – hope I got that right.
Checking online, I see ozokerite wax is a hydrocarbon wax. Any thoughts on the practical differences (pros and cons) between animal/plant based waxes and petroleum-bsed waxes?