Talk about alot of work.
I think I have touched just about every square inch in that room.
The day after the install, we expected them to return to sand it and apply a finish, but they never did. So I fired them! First time I ever did that too. :-)
This last Saturday I got down on my hands and knees and finished the floor by hand. Well not without my random orbit sander, a Porter Cable 7335 (pictured above). I had some 40 grit, 80 grit, 150 grit and 220 grit discs along with a shop vac based dust collection setup.
The sanding process went like this:
- Start with 40 grit, every 18 inch square of floor start sanding to blend all the height differentials. Pay special attention to the plank ends, where the height differences are most notable.
- On large differences, tilt the sander slightly and apply pressure to the area to bring it down, while moving in a back and forth and small circular motion. Do this for 3-5 seconds, then place the sander flat and aggressively sweep the surrounding area to feather it in.
- Feel the floor constantly to see where more work needs to be done.
- This 40 grit smoothing took me about 3.5 hours to finish 135 sq ft. I wore ear protection the entire time.
- After the 40 grit smoothing, take out the scratch marks using 80 grit. I used a slow, uniform and linear row-by-row pattern, going with the grain, back and forth across the entire kitchen. This step took about 30-40 minutes to do the 135 sq ft.
Since it is the dead of winter here, I was going to use a water-based polyurethane so avoid the toxic fumes of oil-based. After some research, I found that it is an excellent and very hard coating but definitely lacks in the color richness department. This is where a sanding sealer comes in to play. A sanding sealer is typically a de-waxed shellac. When this is applied it seals the surface grain and allows light to reflect off of the wood surface, giving full color and grain presentation. Follow this with a water-based polyurethane, which dries perfectly clear when properly applied, and what you see with the sanding sealer is what you get. It is important to only use a de-waxed sanding sealer with a water-based poly, since wax and water-based finishes do not mix!
I used a Zinsser Bullseye Seal Coat, 1 quart was enought to cover my entire 135 sq ft.
http://www.zinsser.com/product_detail.asp?ProductID=72
For a water-based polyurethane I used Varathane Water-Based Diamond Floor Finish
http://www.rustoleum.com/CBGProduct.asp?pid=66
I also purchased the special broom handle mounted applicator pad, mineral spirits and some painters rags.
The finishing went like this:
- Vacuum and wipe down the newly sanded surface with mineral spirits, let dry and ventilate.
- Using a wide brush, brush on the sanding sealer. You will be instantly gratified at the gorgeous color. Let set up for about 45 minutes.
- Using a random orbit sander or by hand, sand the seal coat with 150 grit or finer until smooth and uniform.
- Vacuum and wipe down with mineral spirits, let dry.
- I then wiped on by hand an additional thin coat of the sanding sealer, and let it try to the touch. The finish was still very smooth and the color was lustrous.
- Carefully apply 3 coats of water-based polyurethane. Each coat needs to dry for 1-2 hours in between coats. Some tips: pour only a little at a time out of the can on the floor and spread it out using the applicator in the direction of the grain. There should be no white streaks, if there are keep smoothing it out. Work fast, it starts setting up quickly (3 minutes or less). Work only a couple rows at a time and smooth it out uniformly.
- After the 3rd coat had dried properly, I used the random orbit sander and 220 grit to smooth it out completely. Use a hand to feel the surface and get all the bumps and dust out.
- Vacuum and wipe the surface clean using mineral spirits, and let dry.
- Finally carefully apply the 4th coat of water-based polyurethane and let setup for 1-2 hours. This is the final coat and should turn out nice and smooth.
- Wait at least 24 hours before moving stuff back and walking on the floor wearing more than just socks. If you wear wool socks, be careful it's slick!