Hello all,

Newbie here, please be kind

I am ready to rent a buffing machine to prep a poly floor for Bona Traffic HD sealer. The floors are currently water-based poly on oak wood floors. I have done a lot of research and it seems it's a toss up to use 120 or 150 grit screen to cut through some of the poly and have a good base for the Bona Traffic HD. Last I read was to use 120 grit with the hand electric buffer and 150 grit with the big buffer? What grit do you guys think I should use with my hand buffer for the corners and what grit with the large buffer? I have never used a buffer before to do this work so maybe that should be taken into consideration as well.

Thanks!

A new 150 grit screen will scuff the floor enough to give some tooth for the water-based finish. Hand sand the corners with 150 grit sandpaper, folded into thirds or quarters. Use a white pad for a driver for the screen.
Make sure the floor is clean before you start using the buffer. Overlap one third to one half each pass of the buffer. If you have a random orbit or palm sander you could probably prep the whole floor with 150 paper by the time you went out to rent a buffer and then take it back after you finish, and a better job, too. There is a learning curve for new buffer operators. Get some comfortable need pads.
You may find that two coats of finish will look better and be more worthwhile since you are doing all this work. Water-based poly doesn't add much film thickness for each coat.

Thanks for the response Pete. I do have an orbital sander (not random). So you are saying I should use that with 150 paper (not screen) and do entire floor with that first? I thought paper cuts more than screen? What speed should I use from 1-10?

You will be able to tell how much you are abraiding the surface by working within arms reach with the sander. Only dull the surface without removing too much finish. If you are comfortable going on ten you will be able to move faster. Some motors vibrate a lot when on high. On high speed you may want to use 220 and change papers more often.