Hi guys,

Thanks for all your help, my DIY installation of 3/4" unfinished solid red oak looks great so far, thanks to your advice.

I'm going to be sanding my floor myself this weekend. This is my first house and unfortunately I can't afford a professional. Since this is a new installation of unfinished boards, there are small height differences on some of the boards as expected due to milling. After speaking to several individuals here on this message board, we concluded that the new random orbit sanders (U-Sand) won't level the floor. Thus it looks like I'm going to be using a rental drum sander.

1. On the first cut of sanding, some websites say that you should sand at a 45 degree angle on the first pass to the layout of the boards to level the floor. Other websites say to sand at a 15 degree angle. All other runs with the sander are in the direction of the board layout. Which angle (if any) do you guys recommend?

2. Although my installation came out great, there are a couple of spots where there is a slight lump in the floor - possibly due to a joint on the plywood subfloor. These raised areas are very minor, and barely noticeable. Can I fix this by sanding a little more aggressively on these areas?

Thanks again,

Jim S.

15º angle for the first cut to get the over wood.



Careful not to sand down to much on the humps. That big drum can burn through some wood fast if your not careful.

I like to 45 a floor to get it flat. It is not always necessary but we end up 45 ing alot of floors, sometimes twice.
As for the slight lump in the floor. I use the edger to knock down or fix any bad spots in the floor before I drum sand. This will speed up the drum sanding and give you a nice job.
Buddy

If you 45 start with 50 grit. Then 50 grit with the length of the boards.

OK guys! I've been sanding floors since 1980 and used many different types/brands of sanders. When rough cutting the floor (1st cut), if you're using an 8" belt style sander (Hummel, Pro Sand), cut at 7 to 30 degrees, and walk quickly because that drum is turning at 2800+ RPM. If using a 12" Clark American style drum sander, it is not necessary to angle cut the floor as the drum speed is slower, 2200 RPM plus the pressure is spread over 12" as opposed to 8"; hence you will have less dish out on open grain woods (ash,oak). Lagler (Hummel) recommended diagonal sanding in response to dish out problems higher speed belt sanders can cause. Any floor sander will cut faster at an angle and level better. For most new floors ( 3/4"x2&1/4" oak strip, unfinished), using a belt style sander, try starting with 50 grit and walking at a brisk pace. You may find you need to switch to 40 grit. Traverse the floor at a 15 degree angle. When finished, if using 50 grit, go to 80 and cut with the grain. If using 40, go to 60 and cut again at a 15 degree angle BUT IN THE OPPOSING DIRECTION. Then switch to 100 grit for the final pass with the grain. Contrary to populer thinking, it is not necessary to make a pass with the grain after diagonal cutting with the same grit. Simply go to the next grit up as I outlined above. If your sander is performing optimally and you are using it properly, you will not leave diagonal sanding marks. I've been doing this successfully for 15 years. Before that, I always sanded with the grain and got dish out. Now, I try to drum (belt) sand the minimum and hardplate after to minimalize dish out.

Thanks again guys!

I sanded this weekend and the results came out excellent! For sandpaper I only had a choice between 60, 38, and 20 grit for the initial cut, so I chose to use 60 and make several passes. It leveled the floor almost perfectly, and I don't have any noticeable waves in the floor. After about 4 passes with the 60 grit, I went to 80 and then 100. I vacuumed thoroughly after each sanding, tacked the floor with a clean damp rag, and then put the first coat of Varathane water based poly on. It looks awesome so far.

Thanks a million,

Jim S.

Your welcome Jim, now please send your certified check for $200.00 to my address for the advice. JUST KIDDING!

Gary, raise your consulting rates!

Your cutting my throat there!

Sorry! Figured is was about right for ten minutes of writing! Now if I had gone to a job-site, that would have been a different story!