How long does it take for an application of cold wax medium atop a finished painting to fully cure, so that a second layer of medium can be appplied on top without affecting the first? Or does the underlying medium stay indefinitely somewhat soluble when a new layer of medium (with some percentage of solvent in it’s formulation) is added on top? Are cold wax mediums that are soluble in mineral spirits (such as Renaissance wax) stronger than those soluble in OMS (Gamblin’s cold wax medium); i.e. is the fact that whatever resin in the medium is soluble in a stronger solvent mean it contains a stronger resin? Thanks, Koo Schadler
Cold Wax
Solvent requirement of waxes are tied to their melting point. The melt point of the wax in Gamblin Cold Wax Medium is > 150 ͦ F. From what I can find online, this is similar to Renaissance Wax. So, I think it’s splitting hairs regarding applying one of these wax products over the other. Either way, the wax coating should be thoroughly dry before adding another layer. For Gamblin CWM, consider waiting at least 3 – 4 days.
Kind regards,
Scott Gellatly
Gamblin Product Manager
Hi Koo.
I have little experience with these mediums and have sent the question to others more knowledgeable about the subject.