I don't know anything about the putty, but Zinser makes an oil-based primer that is sandable. I used it on my wood trim to help mask the grain. It didn't completely cover the grain but it helped hide it considerably, and at under $30 a gallon you may want to try it first. I would use the oil-based primer, sand it, and then coat with a latex paint. Using two different types will block any stains or oils from coming through the top coat.

Before anyone says you can't paint latex over oil primer - Yes, you can -and should- use oil PRIMER under latex paint on wood surfaces.

I am not sure how practical it will be to hide the grain of oak. It's not just the little open pores that oak has, it's an all-over heavy grain. It seem that hiding that will require that you basically skim coat the entire oak panel with putty and sand it all smooth. That seems like an awful lot of work! Painted oak doors with the grain showing are actually quite pretty. If you want smooth doors, it may be cheaper to just buy some new paint-grade doors made out of MDF or even maple.

Hi, I am in the middle of painting my oak cabinets. The prep is long and grueling..but worth it. I used a product called Pore-o-Pac, oil based. It is a brush on wood grain filler. Very time consuming, did 2 coats on each door front (not the backs) and all the cabinet frames. You cannot see the grain through the paint.

This is what I did: Sanded the surfaces with 180 sandpaper, washed with TSP. Let dry thoroughly (and then a little longer)...Then painted the grain filler on. (My little trick is to buy an empty one gallon container, dump the qt size grain filler can into it. This way you can stir it up very nicely. You can thin this product with mineral spirits.) You leave it on for a few minutes, then use the scraper to scrape across the grain at a 45 degree angle. Next it says to wipe it off in the direction of the grain lightly (I guess so as to not pull it out of the grain). Let it dry for 24 hours. Then, if you really want to hide that grain..do it a 2nd time. I even did 3 coats on 2 doors that were very heavily grained. Also, as you are scraping it off, I would just dump it back into my container, if the product started to get too thick--just add the mineral spirits!

It does take a long time, but really--no grain! Oh yeah, another little tip: The ends of my cabinets are laminate--the fake wood to look like the grain. I used a product that is a primer for painting over plastic. I got it at Lowe's, it is their brand--sort of like the Krylon Fusion, but it was a clear primer. After I sealed off the area where there would be overspray, I just followed the directions, and then I was able to follow it with the primer I used on the cabinets! So far so good. Make sure there is plenty of ventilation!!!!!

As I mentioned up above, I bought 2 quarts of this stuff, it really goes a long way.

Good luck!

Here is a link that might be useful: Pore-o-Pac

Thanks all. I was able to find the Zinser primer. I've also started the grueling process of cleaning, deglossing and sanding...still haven't made it to the priming stage. I think I'll try the Zinser primer and see how it works before I move on to something else. I don't think I'll find a little grain showing through a problem. I found some really thorough instructions on the This Old House website.