How to Refinish Your Floor with a U-Sand Sander

At U-Sand, we’ve developed easy to use floor sanders that represent the 21st Century’s cutting edge of sanding floor machines.  But above all, we want you to have a safe experience.  Always have your U-Sand Operations Manual on hand and follow the instructions and safety precautions carefully.

Sanding your Floors with U-Sand Equipment

Congratulations, you’ve decided to sand and refinish your hardwood floors with easy-to-use, patented, Random Orbit Floor Sanding Equipment from U-Sand.  
 
Before beginning the process, let’s look at the safety features of the equipment you will be using. 

Safety Features

ALWAYS UNPLUG THE UNIT BEFORE CHANGING THE PAPER. 
 
Lean the machine back until it is parallel with the floor. Press the hook and loop paper discs to the backer pads on the bottom of the unit.  To remove the sandpaper, pull on the paper from the edge.
 
Now that you are familiar with the equipment let’s get started.

Prepping the Room for Sanding

• Remove all furniture, appliances, floor coverings, etc. from the area that you will be sanding. 
   
• Thoroughly check the floor for large splinters or nails that have worked their way out over the years and reset them as necessary.   To set nails you will need a nail punch and hammer.  Tap the nail head until it is slightly lower than the current board height of the floor.
   
• Removing your existing baseboard, base shoe, or trim is not necessary, as U-Sand floor sanders are able to sand right up to the trim in your home. 
   
• To prevent any airborne particles from spreading throughout your home, you may want to apply plastic drop cloths to the doorways of adjacent rooms.
   
• Erect a fan in a window of the room where you are sanding and set it to push the air out of the home. This will provide a more comfortable working environment and remove any fumes that occur when using a tack cloth, staining, or applying the Polyurethane finish.

Remember, when working you can move the sander in any direction and do not necessarily need to go along with the grain of the wood because of the random orbit action.

Check the Existing Finish

You will need to determine if the existing finish is Polyurethane or Shellac. 
 
To do this, while wearing disposable, waterproof gloves, take a bottle of denatured alcohol and a soft cloth and wipe the floor in a small area.  See if the finish softens; if it does, the finish is Shellac.
 
If there is a heavy coat of Shellac on the floor, it can be chemically stripped to reduce the amount of sanding discs needed to remove the finish. 
 
FOLLOW THE MANUFACTURER'S INSTRUCTIONS FOR USING DENATURED ALCOHOL AND CHEMICAL STRIPPERS. 
 
If you do not chemically strip your floor you can sand the finish off.  Keep in mind that during the sanding process, the temperature of the rotating discs raises enough due to friction to soften Shellac.  Move the machine quickly to reduce the amount of paper plugging.  If the paper plugs or simply stops sanding, you must change your paper more often with a coarse grit such as 24, 36, or 40 until the Shellac is removed from the floor.

Sanding the Floor

Now you are ready to begin sanding your floor.   Attach the unit to a separate vacuum system; the attached adapter will accommodate a 1.5-inch vacuum hose.  We recommend starting with 36 or 40 grit paper once any Shellac is removed or for Polyurethane coated floors.
 
These grits are used to remove the existing finish, any imperfections, unevenness, ripples, or start-stop lines already in your floor.  Always remove the vacuum system and empty the contents into a metal container with a lid in an area away from your workspace when not using the machine.
 
Change the discs when the paper becomes dull, this may occur after sanding for approximately 15 minutes.  After one pass over the entire floor area, you will be able to identify any areas that may need additional sanding and how much sanding you will have to do to level your floor.

• Use progressively higher grits.
   
• Vacuum the floor completely between grits of paper to prevent scratches from the coarser abrasive that may have fallen off and were not removed from the floor.
   
• Paper usage.  For a room that is 10 x 10 (100 sq ft) you will need approximately:
  • 20 discs of 36 or 40 grit paper - more if removing Shellac or heavy build up.
  • 8 discs of 80 grit  - make sure to remove any scratches left by previous grits with this grit.
  • 8 discs of 120 grit to fine sand the whole floor to ensure uniformity.
  • If you started with 24 grit, use 40, 80 and 120 in this order.
  • Skipping grits may not provide the desired results.
     
• Vacuum thoroughly

Gaps in Boards

In some cases older homes have floors that have become loose and gaps appear in the boards.  In newer installations, you may have nail heads that are unattractive. 
 
These gaps and holes can be filled using trowel-able wood filler (available from your local hardware store). This material can be applied to the whole floor or spot applied as necessary.
 
Once the wood filler has dried, re-sand your floor with the highest grit used, typically 120. 

Hand Sanding and Scraping

A small amount of hand scraping and hand sanding may be necessary in corners and under
radiators.  
 
Review your entire floor at this time and make sure are no visible scratches.  You may sand with 180 grit if preferred. And don't forget to vacuum thoroughly.

Wipe with a Tack Cloth

To remove any remaining debris, wipe the entire floor with a tack cloth or with a cloth dampened in Mineral Spirits or Paint Thinner from your local hardware store. At this time make sure you have adequate ventilation, including the window fan mentioned earlier.
 
Follow the manufacturer's instructions for using Mineral Spirits, and Paint Thinner.

Apply Stain or Varnish

After the floor has completely dried, apply your stain or varnish following manufacturer's instructions.

Buff between Coats

If you would like to buff the floor between coats of Polyurethane, we generally recommend using buffing pads after the first coat of Polyurethane has dried completely.  Buffing pads are available where the machine is rented.

During this process, it is easy to see where you buffed the floor as the finish becomes dull after buffing.  It is very important to keep moving the machine when buffing as the Polyurethane coat is very thin and can be removed quickly. 

One pass is sufficient. 

After buffing, once again thoroughly vacuum and tack cloth the floor before applying any remaining coats of Polyurethane.  Make sure you remove the vacuum system from the sanding unit when not in use and empty the contents into a metal container with a lid away from the workspace and other flammable products.

Returning the Floor Sander

Prior to returning the floor sander, unplug it from the outlet, remove the attached vacuum system and empty contents into a metal container with a lid away from work area and other flammable products, wrap the cord around the handle, and leave last sandpaper discs used on the machine.

CONGRATULATIONS YOU HAVE SUCCESSFULLY FINSIHED YOUR HARDWOOD FLOOR!

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