Refinish Hardwood Floor

Project - Advanced 
Tools - Industrial Floor Sander, Floor Edger, Orbital Hand Sander, Scrapper, Dust Mask, Paint Pole, Paint Tray
Materials - Sanding Paper (rough, medium, smooth) plan on buying a lot for all the tools, Wool Applicator,  Floor Stain, Floor Polyurethane, Gloves, Tack Cloths  
Cost- $350.00-$400.00
Time - Depending on the Polyurethane used (waterbase or oil) it will take you a day or three to do.

This project consisted of a hallway and a bedroom to refinish. The hallway is pictured here and you can tell that part of the floor had already been sanded with a drum sander. The homeowner had started the project and did not want to finish it. The homeowner knew how difficult the work was due to the layer of finish that was on the floor. To give you some background on the home, it was an old farm house with maple floors. The top layer of finish was a varnish or a version of a varnish. As the homeowner learned from this project that varnish when heated gums up the sanding disks in a hurry. Varnish is better removed with a liquid stripper but the fumes can be overwhelming and not good for your health.

For about $40 a day you can rent floor sanders to help with this type of project. However, these items are big, heavy, and can easily damage your floors fast. This project is best left up to someone that has done this at least three or four times.

A sanding edger was rented to finish this project since the center of the rooms were already completed. It took a good six hours to remove the finish from all of the edges in the hallway and bedroom. The edger is the the most back breaking tool to use to sand a floor. Using the tool requires great upper body strength and leg support to control the tool.

During this part of the sanding stage it was made clear why the homeowner had trouble with sanding the finish off the floors. The old finish would gum up due to the pressure and heat build up from the sanding process. This would then gum up the sandpaper causing the sandpaper to not work properly. A lot of sanding disks were used during this process.

Note: Maple is a soft wood unlike an oak. The wood can be damaged quickly and burned if you use the sander in any one area for a long time.

After all the sanding was completed a vacuum was used to vacuum everything. This includes the walls, molding, floor, and ceiling. The next step in cleanup is to remove the small particles of dust left behind from the vacuum. Tack cloths can be used or a rag dipped in mineral spirits can be used to wipe down the floor. When using water based polyurethane you can use a light wet rag for cleanup. When cleanup was completed staining began. This stain was a rich mahogany color. After applying the first coat of stain all the imperfections became noticeable. The stain enhanced swirl marks left by the sander, blotch spots in the wood, and areas of discoloration. So the floor was then sanded again with a finish sander. The finish sander that was used used was a four rotating disk sander that you can operate standing up. An 80 grit sand paper was used to remove these blemishes. One nice thing about staining the floor and then re-sanding it, is that you can tell where more sanding is needed. This helps because the stain has soaked into a blemish and will not be removed until the floor is sanded level with the surrounding area.

When this phase of the sanding was completed cleanup began so that all the dust can be removed. Again the stain was enhancing the swirl marks left by the finish sander. So it was back to the rental store to get the orbital square head sander with 120 and 150 grit paper for the final finish sand.

Four hours after sanding and cleaning the third time the floor was ready to stain. This was a huge improvement over the first staining process. The photo to the right shows the final stain process but as you can see in the middle of the picture are what looks to be (blood drops) blemishes in the floor. For some reason these floors had them all over after the first staining process. The more the floor was sanded the less likely they were seen. The marks would only appear after stain was applied over-top of the area.

Note: Floor cleanup from saw dust and debris was done with paint thinner applied to a rag and wiped out over the floor. Water is not recommended because water will raise the grain and using too much will cause water marks. After the paint thinner evaporated the stain was applied with a rag. Excess was wiped off as need.

This was the floor in the bedroom that was being finished also. The stain was applied in two coats to get the color the homeowners wanted.

According to the manufactures directions wait eight hours before applying the polyurethane (Varathane ) Apply the first coat of poly by using lambs wool applicator on a painters poll. IMPORTANT: After removing the new applicator from its packaging take some tape (any kind will do) and remove all the loose fuzzies from the lamps wool applicator. This processes is like removing fuzzies off a sweater. You do not want the fuzzies in the poly because they will show up on the floor.

Use a bright halogen light to see where the poly had been applied. This is important because when applying the poly you want to keep a wet edge at all times.

When applying the poly start in an area furthest away from your exit point (for obvious reasons). More than likely this will be at a wall. Put the applicator into the poly and make sure the applicator is soaked with poly. However, don't let it be so soaked that it is dripping all over. Apply the applicator to the floor gently so that it's not puddling on the floor. Pull the applicator instead of pushing (walking backwards across the floor). Once the applicator gets dry, re-dip and start the process over again. Brush over the wet area to smooth out the brush lines and the start and stop points. Do not lean into the applicator because it will puddle the poly onto the floor. Always use a wet edge when applying the poly to a new dry strip on floor. With the poly it is somewhat self leveling and most of the brush strokes will level out in minutes. Do not over work the poly.

After applying the first coat let the poly dry. When the poly is dry you will be able to see your mistakes.

Before applying the second and third coats sand the floor with 120 grit paper. Always sand with the wood grain. During sanding will remove light blemishes from the poly(air bubbles, debris, etc). During the sanding processes the floor should turn a white color. The white sanding dust can be cleaned up with paint thinner/rubbing alcohol. After cleanup apply the next coat.

The pictures shows the floor with the third coat of poly. This turned out really nice and clean.

Project completed! Even though there was some real problems and hard labor involved this project turned out nice. Do not under estimate the amount of labor that goes into refinishing a hardwood floor. A good estimate is to plan about a week of not being able to live in the rooms/house that your are refinishing. If you are thinking about doing one room at a time then plan on doing the final coat in all rooms at the same time.

The cost for renting all the tools and buying the sandpaper was around $175.00. The stain and poly cost around $100. (Varathane) is a good choice for poly but it is expensive at around $40 a gallon. It goes on smooth, levels out, and has nice working properties. It pays to pay the extra dollar and get a superior product).

UPDATE-08/07: The Varathane that was used was a gloss. There were small problems with applying the final coats in that the poly would have dry spots or off gloss spots after drying. There was extra coats laid to try and stop this from happening and still the same problem every time. The homeowner called Varathane and they said to add mineral spirits to thin out the contents before applying to the floor. The directions on their can say not to add anything to thin the contents. So There is some conflicting information by Varathane about this problem. The cost of wasting three or four gallons is quite expensive. Varathane needs to update their application directions on their can, or update their product in the can. However, after adding the appropriate amount of the mineral spirits the application went on smooth and the end result was what is expected.