This is my first post and my first floor installation. It is in my own home. I've searched and read but I am still coming up with the same question. The rep from the mill that produced my flooring is pretty insistent that I trowel fill the gaps. I had planned on spot filling with different colors of Elmers "Carpenters Wood Filler" depending on the color of the wood around the gap. I nailed the flooring down with a Bostitch nailer and Bostitch hardwood flooring nails. It is tight and there are very few gaps and also a few knots with cracks (the wood is 468 sq ft of select with 32 sq ft of character grade mixed in randomly). The wood is not end matched so I used my miter saw to get a good smooth and square end.

I am having a hard time seeing the need to trowel the whole floor when there aren't that many gaps. I'm also worried about color matching the filler. The rep suggested cherry color as a good match but as you can see the Madrone is multi-colored. I read about using Glitsa wood flour cement and sanding dust. I read Glitsa's instruction sheet for that product and it says that a drum sander must be used to remove excess cement. I was planning on using the square floor sander from the local tool rental. Frankly I'd like to stay away from the drum sander as I know it's a hard machine to master . I have plenty of experience with a floor buffer (10 yrs USMC) but I can't imagine that is anything close to a drum sander.

Please give me some advice . Should I just go ahead and spot fill as needed or should I trowel the whole floor? The finish that I'll be using is OSMO Polyx Oil.

Thank you.

What you may want to do, and what I would do, is buy a few different colors of Woodwise Wood Patch.
http://www.woodwiseproducts.com/woodfil ... patch.html
It can be used at anytime during the finishing process, being that it is waterbased. You can use it to spot fill prior to final sanding or even after a coat or two of the floor finish. You can work it into any nail holes or gaps and even mix the different colors to get just the right shade. As it dries, it will lighten, then return to it's original color once a coat of finish is applied. About trowel filling. Some finishers believe that all floors require it. I don't. Very porous and grainy woods may benefit if one utilizes it as a grain filler. But I just build up the finish to fill in the grain. Looking at your floors, a square buffer will take many hours to flatten that floor and eliminate all the overwood. Be prepared for that, is all I can say.

Its probbally going to take longer but on 500 sf you could still get it cut down in a day. Nice work on those corners btw.

I'll take that advice and buy some Woodwise. Thank you.

Regarding the square buffer, I expected it to take awhile so I'm planning for a whole weekend of sanding. That'll be next weekend though as I'm going let the installed floor adjust for a week before doing any finishing. It sat in the rooms for 12 days before I started the installation but I want to be sure that it has some time to adjust to being nailed down and also adjust to the subfloor. I don't know if that is necessary but I've read that the longer it has to acclimate the better off it'll be in the long run.

Thanks for the props on the corners. I test fitted a 90 degree junction at the hallway ends and didn't like how it looked. After testing several configurations the stepped pattern is what I though looked the best and fit the best too. I had to trim the tongues off with a wood chisel and a small block plane to make the joints nice and smooth. Over all I'm quite happy with the progress and happy that I decided to do the work myself.

My hat is off to you fellas who do this for a living. There is a lot of work involved in hardwood flooring.