Varnish before weathering - polyurethane? acrylic?

Erik, 

I wouldn't use acrylics to create streaks; use oils or mig enamel products instead. When using oils, use something like mig enamel thinner to thin and streak the oils (I used turpentine and it was quite strong, causing the varnish coats to become mushy). I paint with tamiya acrylics, and seal it up using testors dull coat (the dull cote in rectangular bottle with pink label, thinned with testors lacquer thinner - cylinder bottle with black label). Then I typically begin weathering with a wash around details, then some oil paint streaks and fading, and finally pigments. The testors dullcote stands up to these products, thinners, and pigment fixers. Only problem I've ever had is when I used turpentine with the oils, which is why I switched to mig enamel thinner. You could also try AK thinner. Also, I recommend abteilung 502 oil paints, but if you don't want to order, the local art shop should have Winsor Newton "Winton" oil paints. I've heard that Wilder weathering oils and Van Gogh oil paints are good (never used them myself).

Kien

Thanks Tojo72.  I have not tried a acrylic clear yet.  Never thought about it, I always thought something that is normally water based would not be able to stand up to oil paints thinned with turpentine.   Will give it a try.  Have you tried acrylic tubed paints instead of oil paints for creating streaking and rust?

I know you mentioned before about possibly moving to the Asheville area.  I can check out some homes and send pictures if you find some listing you are interested in.

Erik

Do not use the polyurethane if you are using paint thinner in your washes. It will mark the stuff.  Polyurethane is okay as a final clearcoat, but not under weathering, unless it is water color wash.

 

If you painted with enamels,you need to protect with an acrylic clear if you plan to use oils or enamel washes.Same if you paint in acrylics,then you must protect them with lacquer clear if you are weathering with acrylics.You can weather with the same medium you painted in unless ypu protect it.