Varnishing with a regalrez based varnish too soon.ApproveRejectUn-ApproveSubscribeUn-Unsubscribe
Question asked 2019-05-19 21:24:29 ...
Most recent comment 2019-05-31 18:12:24
Oil Paint
Varnishes
The general advice is to wait 6 - 12 months before varnishing an oil painting.
Specifically regarding regalrez based varnishes, Gamblin suggests that a painting can be varnished with Gamvar as soon as it is touch dry, which contradicts advice from George O'Hanlon and Virgil Elliot.
What I would like to know is, what are the consequences of varnishing too early with a regalrez based varnish?
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Moderator Answer
(brian baade)
I am going to send Gamblin a note to see if they want to
comment here. Perhaps they have done some definitive testing and I am in the
wrong. For the moment, however, this is one of the only subjects where I disagree
with the folks at Gamblin, and I do so for the following reasons: It is
generally believed that early varnishing causes a similar situation to that of
overpainting before the previous layer has had time to sufficiently oxidize.
The upper layer can then set more firmly than that below it. Someone might say
that the lower layer will oxidize over time even through the superimposed layer
but we have ample examples of paint defects cause by artists overpainting too
quickly, resulting in wrinkling and even alligator-skin like fissures. Likely a
low molecular weight resin like Regalrez is likely less likely to allow oxygen
to penetrate than even an oil layer.
There is also the notion of the creation of an interactive
zone. It is generally thought that while oil paint is fresh, it is more
receptive to absorbing additional layers. This is the counterpart to the
concept that old oil paintings have a surface that is “closed” and layers
applied at a much later time do not adhere very well. More germane here is the
idea that if varnish is applied too soon it can partly incorporate itself into
the oil film creating a layer that will be more sensitive to solvents.
Having written all of the above, I have to be honest, I do
not know of any scientific studies that have proven or disproven these
suppositions. Perhaps Gamblin has and I am way off base. Finally, this is one
of the subjects that I hope to study when I get an artificial weathering
instrument. I expect to have access to one in the next year.
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Moderator Answer
To be clear, our recommendation states: “All Gamvar
can be applied when the thickest areas of your painting are thoroughly dry and
firm.”
The reason that we don’t conform to the “6 – 12
months” rule of thumb is an acknowledgment that this rcommendation doesn’t
speak to how the painting was made and with what materials. Paintings done with
fast-drying colors/mediums in thin layers are ready for varnishing sooner,
whereas paintings made with slower drying colors/mediums in thick layers
require longer dry times.
Let’s also consider that the reasoning for the
original “6 – 12 months” recommendation came out of the poor qualities of
dammar varnish – namely its brittleness and its formulation (and subsequent
removal) with turpentine – which has twice the solvent strength as Gamsol (the
solvent in Gamvar). Regalrez is more inherently flexible than dammar. Since
Gamvar’s launch in the early 90’s, we have never had any reports of Gamvar
cracking as a result of premature application.
Scott Gellatly | Product Manager | Gamblin Artists Colors
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Moderator Answer
(brian baade)
Thanks for the clarification Scott.
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