paint to cover brown stained wood trim
I have a 60s house with medium brown stain on oak (I think) wood trim, doors, doorjambs, baseboards. I am painting all of this white and it's a massive job. It seems to take 4 coats of paint, 2 primer coats(CIL Dulux acrylic latex primer),and 2 semi-gloss coats (Behr int. prem. acrylic latex semi-gloss) to cover the brown. I find it really difficult to work with latex semi-gloss paint. Years ago we always painted wood with semi-gloss oil based paint and it turned out much nicer. I have painted 2 of my 6 doors with the latex semi-gloss, and have begun to paint the rest with the latex primer, and wonder if I can switch to oil based paint at this point, including putting oil based semi-gloss on top of the latex semi-gloss, just to make it uniform. To recap: can I paint oil-based semi-gloss on top of the latex primer, and also on top of the latex semi-gloss? What kind of brush should I use with the oil base paint if I go that route?
Re: paint to cover brown stained wood trim
You have discovered the shortcomings of acrylic/latex paints for trim. They are very hard to brush on and not leave brush marks. They do not level out as does oil paint. Further, acylics retain a gummy feeling, especially in humid weather. Acrylics can be sprayed and give a smooth finish, but the average homeowner is ill equipped for spraying. Also, it is difficult to spray in an occupied home environment.
A quality oil enamel applied with a quality bristle brush can come close to a sprayed finish in appearance. Were I starting from scratch in your situation, I would have used an oil enamel undercoater, followed by two coats of the finish oil enamel. The oil undercoater will help fill the grainy nature of oak woodwork.
You only need to undercoat once. The undercoaters' primary function is to bind to the slick existing varnished finish. It also adds white blanking of the dark wood. However, undercoaters have less white pigment than white paints. From the standpoint of blanking out the dark woodwork, the paint itself gives much better coverage than the undercoater. Further, unless you have a decorative need for a pure white, you will be much better off using a white which has been slightly gray down with lamp balck and/or raw umber. A few drops of these will dramatically improve the blanking ability of the white paint.
For years I used Benjamin Moore's Satin Impervo oil enamel as my primary woodwork paint. BM's "Decorators White" has already been dulled down colorwise. Two coats of Dec. White over undercoater would blank out even black!
I usually used Purdy's Oxhair brushes when using oil paint. Foam rollers are also of good use in covering the larger areas rapidly, followed by knocking down the roller dimples with the brush. If the oil is somewhat draggy, a little Penetrol will give it more glide and help in its leveling out. Keeping oil paint warm also greatly improves its flow.
As to your question about covering latex with oil: For sure you can go over the latex primer with oil. You can go over the latex paint with oil also. I would not advise the reverse, however, at least, not without priming the oil paint first. I would give the latex paint several days of curing before going over it. The latex primer cures faster than the paint.
A lesser sheen than semi-gloss would also downplay the brush marks you have already made in the lates paint.