I like to use Purdy brand natural bristle brushes when I brush on oil based finishes. I cleaned a brush in laquer thinner because it was building up and becoming stiff. Cleaned it fine and I shook it out and brushed it with a brass brush before using it. I am using spar urethane for a covered patio project. It left a lot of small flecks on the piece after it dried during my 2nd coat. I sanded them down and it should be fine if I add a light 3rd coat, but... The brush is dry now and when I shake it I see a lot of fine air borne particles coming off the brush. Did I ruin this using the laquer thinner?