Stain first or after?

Stain first, then touch it up after it is installed.

Should I stain and varathane or just stain? What happens when you stain over varathane?

About zero in the stain department. Varathane as in Lacquer? Might not be good for the plastic.

Stain and varathane prior to installing the sill. The stain wont do anything on the varathane, it will just wipe off.

I agree with others, get them cut to proper size, test install, then stain and finish. Install them and nail them down, (you were going to pre-drill the nail holes weren't you?) Then a light sanding with 400 grit or so, and a 50% thinned coat of varathane will cover any dings you made installing them. After that coat dries, and you sand/steel wool it smooth, then get some putty from the hardware store that matches the wood, and putty the nail holes.

If you fill the holes before you stain, you have NO guarantee that the stain will look the same when applied to the filler as applied to the wood. DAMHIKT

Your Dad's a smart guy (this time).

Old Guy

Varathane is a brand.

Which Varathane product are you asking about?

You can fill the nail holes with a putty type filler that closely matches your stain after you stain an install the sill.

THANKS for all of the advice.

Staining in two stages or staining and patching often show signs of a 2 step procedure. Put masking tape over the parts that you do not want to stain. I'd install, then stain.

I assumed he was referring to their poly product...