Preparing Finished Interior Doors For Painting

New to the site, absolutely great! I am preparing to paint the interior of my house, built in 1959. The trim and doors are finished(varnished?) in a blondish brown color. Wood trim is a softwood(Pine?) same finish. Doors are hollow no pannels.I plan to paint the trim and doors. Can I prime the trim and doors and then paint or should I sand the doors and trim first? I am worried the paint will not stick.

Thanks for your help.

 

Welcome to the forums

You are right to worry about the paint bonding. Just painting over varnish/poly usually results in chipped/peeling paint.

The proper way to paint previously varnished wood is to first sand, dust and then prime with a solvent based primer. Then it can be painted with either latex or oil. 1 coat of primer is fine but it usually takes 2 coats of finish to completetly cover the stain.

Personally I like to wipe the doors down with deglosser before applying the primer. I also prefer using waterborne enamel. It dries harder than latex, quicker than oil [and less odor] and cleans up with water. It does cost more than oil or latex but well worth the price IMO.

 

Sand then prime (solvent-based primer)
Wiping with a tack cloth or swiffer will help remove the sanding dust before priming

 

Thanks again for your help.