How To Refinish Hardwood Floors
The following guide is designed to help you better understand how to prepare your hardwood floor. If you need any further information we are always
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Types of Floor Sanders
Orbital floor sanders consist of a 12" x 18" sanding pad that oscillates back and forth in an orbital motion. This ensures that no repetitive sand scratching will occur so it's safe to use for cross grain sanding. If you have a narrow hallway, pantry, or entry where the flooring is run at the wrong angle to use a regular drum floor sander the orbital sander would be a better choice. Because the movement of the orbital sander's paper is minimal compared to the drum sander it will not leave sanding marks. The biggest drawback to the orbital sanders is that they are much slower than the drum sanders. This needs to be repeated: "They are slow compared to the drum sanders." Drum type floor sanders are 10 times more popular than orbital floor sanders. If you have a job that can be handled by a drum sander you will be much happier using that style of sander. Only use the orbital sander for those jobs that are not best suited for the drum sanders. If you have any questions about which is right for you please give us a call and we'll be happy to discuss your job with you. The following tutorial applies to drum type sanding operations.
What You'll Need
Sanding Old Floors
1. For the first pass begin by installing the coarse paper (#20-3-1/2 grit) on the sander. Curl the edges slightly on the paper (being careful not to bend them too sharp so that the grit cracks) so that they will tuck into the slots on the drum more easily. A paper folding guide is located on the very front of the floor sander for this purpose. Back off the two cam levers on the drum 1/4 turn each to open up the paper slot. The cam levers are in a somewhat half round configuration so when the two flats are facing each other it will be less difficult to insert the paper into the slot. You can look into the slot to verify the position of the pinch rollers before continuing. Each roller needs to be rotated 1/4 turn to hold the paper. Take the wrench supplied with the sander and tighten the cam roller on the left side as you are facing the machine from the front. This is the cam opposite the belt guard. There are arrows on the square part of the cam rollers that indicate which direction you need to go. Then, after the first cam has been rotated 1/4 turn, rotate the second cam 1/4 turn as well. With coarse paper it will take some tugging to get it to go that final 1/4 turn. If you don't have the paper clamped securely in the jaws it will tear when you begin sanding. Also, be sure that it's tight on the drum and not a loose fit or else it can tear as well.
2. Divide the room into thirds. Line up alongside one wall with 2/3 of the room in front of you. Turn on the sander and gradually lower the sanding drum to the floor and immediately begin slowly moving forward. When you get to the end of the wall lift the drum. If you sit in one spot you can sand down too far, so the secret is to keep it moving. Then back up to your starting position and make a second row, being sure to overlap the rows by about 4". If the floor is severely loaded with varnish or paint you may want to sand backwards from the end of the first row rather than return with the drum up and not sanding. If small amounts of the old finish remain, don't worry about it. You can get that on the second pass with the medium paper. If there's a lot of old finish left you may want to run the coarse over it a second time to get it cleaner. The sandpaper doesn't wear out as much as it plugs up and the medium paper has less ability to retain old varnish so it's best to get the most mileage out of the coarse sheets before going to the medium.
3. Once you have worked yourself over from one side wall to the other you can turn the sander around and do the exact same thing in the opposite direction. When finished you'll have a rough sanded floor.
4. Before proceeding with the medium grit it's best to bring out the edger now. Mount a 7" coarse disc to the edger and run it alongside the wall to remove the varnish and blend it in with the main floor area. It's easier to edge sand now rather than waiting until the very end after the drum sander is finished. Be sure to keep the floor edger moving while sanding. You'll achieve better results by keeping it moving in large sweeps than slowly feeding it along. At this point may want to scrape or sand the corners as well. More on this later.
If the boards are somewhat cupped you may need to do this first sanding at a 45-degree angle to the grain. This will help to sand the area down in the saddle of the cupped board.
For the second pass, repeat the above procedure using the medium (36-2 grit) paper. You probably won't have to do any 45-degree sanding at this point unless your boards are seriously cupped. Before you begin, vacuum the floor. After you are finished, vacuum again. If you need to fill any cracks up with wood filler, do it now before you begin the final finish sanding.
What About The Corners?
When you are finished you'll find it really wasn't as hard as you thought and you can now take pride in your newly refinished floor. It will be around for a long time.
Drum Type Floor Sander
Orbital Floor Sander
Begin Sanding - Initial Direction
Sand the Opposite Direction
Edge Sand and Detail Sand or Scrape the Corners
Angle Sand for Cupped Boards
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