How to correct “frosted” varnish


In this video, we’ll identify and correct,
a visually-obscuring issue developed in a matte varnish layer created during varnish
application. On the left we have painting correctly varnished
with a uniform matte finish. On the right side, we see a similar panel where the matte
varnish was directly applied to the absorbent surface. A closeup reveals the mottled surface
caused by the direct application of Matte Varnish. Absorbent surfaces should be sealed with a
gloss layer to seal the surface absorbency. This prevents the varnish from soaking into
the painting surface, and in turn results in a uniform matte surface. However, when the surface has NOT been sealed
first, the varnish absorbs in, leaving the matting solids exposed on the surface, resulting
in a dry, frosted appearance. If an isolation coat or gloss varnish layer
has not been applied, and you do end up with this frosting on an important work, you can
try to correct it. If it doesn’t result in acceptable results, you can always remove
the majority of the varnish and start over. In this example, the initial MSA Varnish layer
was over-thinned yet generously applied. The gloss layer I am putting on is on the
thicker side as you can observe. My goal is to apply one gloss varnish layer
to re-saturate the matting solids on the surface and still seal off any remaining absorbency
as well. I could also work with thinner varnish here, but I would probably need to apply two
or more coats. Note that I am working carefully but rather
quickly because I want to avoid overworking the surface and kicking up the matting solids
too much into the wet varnish layer. After it dries, you can see that it wasn’t
so thick that I lost all of the surface texture of the panel. Now it is time to apply the layer of matte
varnish, using the same technique used for the gloss layer. When applying multiple layers of varnish,
it is important to not overwork the layers. The underlying varnish is reactivating, and
you will quickly find yourself contending with excessive brush drag if you take too
long to apply subsequent coats. Overworking also can reactivate the underlying
layer and cause the two to intermix, resulting in an uneven finish. So apply carefully but
quickly and then leave the wet varnish layer alone and you should end up with the uniformly
matte surface you originally desired. For more information, please visit our website
or contact us in Technical Support!

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