What causes a dull finish?

Why might a conversion varnish that is normally shiny turn out flat? February 28, 2001

I use conversion varnish in my shop and always get a shiny finish. I sprayed a kitchen yesterday, though, and it came out more like a satin or flat finish. It was cold outside--could this have been the cause?

Forum Responses
I don't know what conversion you were using, but the Sherwin Williams is prone to having the flattening agent settle out.

Providing you are using 5's, this is what happened. If you do not stir your finish completely you get a greater concentration of flatting paste on the bottom of the 5. The material will have a flatter look. Lac. tends to have a whitish-looking flattening agent while V.C. is clear. Remove the top of the 5 and stir well.

If you are using conversion varnish, it should not be colder than 60 F, at least for the first two full days of curing. If you allow your curing finish to chill, you run the risk of having an inferior film form.

The film will not properly cure or crosslink if the temperature is not above 65 degrees. 70 is better for at least 4-6 hours. The finish, finishing surface and the air need to be at appropriate temperatures.