Maroger's varnish

[Salamander]

I had these two egg/oil paintings on rsg gesso on birch plywood that were getting eaten by silverfish. So,... what I decided to do was to knife a layer of maroger's medium ( leaded linseed oil with mastic varnish) over the painting to finish it off and proof them from the vermin. Since egg tempera and egg/oil tempera can be used as underpainting mediums I saw no reason why this shouldn't work.
Well,........ The maroger's has flowed to a glass-like surface and almost two weeks later is still not dry...... not just typical maroger's tacky but damp to the touch. It is drying but glacially and it's 85 degrees here.
Why do you suppose this is?

Eric in Oceanside

[David McKay]

I don't know the answer to that question Eric, but what is leaded linsead oil? Can you see the silverfish on the surface or are they embedded in the plywood or gesso from behind? I assume that they are on the surface since that is where you are trying to seal the painting. I am confused, why not just brush them off? I am sure this is a stupid question. :-? David

[Salamander]

silverfish are primitive arthropods. They eat sugars and starchy things like watercolour binders which contain honey, bookbinding glue, and egg tempera binder.
leaded linseed oil is linseed oil that has been heated up with an amount of litharge (lead oxide). This is then called black oil. It is valuable as an oil painting medium.... especially when combined with mastic varnish to produce maroger's medium.... but a valuable additive to the painting process in it's own right.
when making up a tempera grassa I have found that the black oil alone or inconjunction with either clove oil and or oil of spike generally deters the vermin. these two paintings in question however are traditional et medium and the siverfish ar beginning their attack. At this point the maroger's has dried appreciably and I expect that it will eventually dry totally. It has put a very high gloss on the et and at the ame time heightened the jewel like quality of the painting.
best,
Eric in Oceanside

[Dimitris C. Milionis]

silverfish

so thats the fast slim little guys that I see in my painting tools box that might carry some specs of food material that draws them to it

[Alessandra Kelley]

Hm. But maroger's medium is a painting medium, not a varnish. That is to say, it doesn't necessarily have the qualities you would want for a long-term solution.

Layers of pure linseed oil without any pigment not only yellow over time, they wrinkle and warp, looking rather like an orange peel. The presence of lead in the medium may change these handling properties, I don't know.

More importantly, if anything goes wrong, the oil cannot be removed. The thing about varnishes is they are supposed to be removable. If you want to protect your work from vermin, and give it a lovely high gloss, surely varnish is a better solution than lead in oil?

[Salamander]

I think you are right.... varnish or maybe a wax.

[Dimitris C. Milionis]

I am starting to respect the WAX option, got a nut case buddy in the trade who has stoped all varnishes and only uses wax almost on all his art projects from ET to oil to acrylic even watercolour

beat that for a tough guy who believes in tradition

[Alessandra Kelley]

I have waxed a few oil paintings. I wonder about its permanency, but on the whole beeswax is pretty durable stuff. I can't speak for ozokerite or whatever the petrochemical waxes are.

[Salamander]

wax is supposed to be the most archival of all painting mediums

[Alessandra Kelley]

Well sure, as a painting medium, but how is it on its own? The presence of pigment changes the drying properties of a medium -- thus oil paints last better than pure linseed oil films. Does pure wax hold up, or does it crack?


That said, I have heard great things about beeswax, as long as it is purified enough (honey being bad for a work's longevity).