DIY Hardwood Floor Refinishing
Many thanks to Ian Gilham, resident of the UK in allowing the use of this information regarding refinshing a wood floor. Ian's experience in the wood flooring trade spans several decades where most of his work was done in Australia. The following article was written by a friend of Ian's who now resides in Montana. Thanks Ian!
House Moved 35 Miles
This essay chronicles the result of my pestering Ian Gilham for information about sanding the wood floors in my latest remodeling project, a house I moved 35 miles, gutted, and am starting to put back together. In exasperation at one point, he mentioned that it would be a lot easier to show me how to sand my floor than to answer another thousand questions online!
Having already gotten quotes way beyond my budget for the work, I did the calculations and offered a plane ticket if he would hop over the pond and teach me to do it myself without ruining the floor, something a flooring contractor certainly wouldn't have suffered. The floor was narrow strip red oak flooring in fair condition with yellowed varnish, no stain, about 1000 square foot area. There is an approximate 3-square-yard area of water damage and 3 small stains from pet urine or something similar. We collaborated on the text and photos that follow.
Rental Equipment Sources In The Sticks
All the work was done with machines hired from the local rental company. The drum sander pictured is a standard 8" Clarke. Here in the states, places like Home Depot, Lowes and other rental outfits have been aggressively adding more selections due to the popularity of DIY projects, and many finding wood floors under years of carpeting.
All equipment can be obtained on a daily or weekly basis, with the latter being less expensive if your project is large as in this example. Besides the drum sander seen on the right, these rental centers also offer flooring edgers and a wide array of sanding paper and finishes.
Diagonal Sanding Cut - First Pass
The first pass was made diagonally across the floor, using 36 grit paper. Sanding diagonally across the grain is far more efficient at flattening the floor, but the scratches are deeper and more difficult to remove, so the preferred procedure is to sand diagonally both ways and then along the grain with each grit. In many cases with floors covered by carpet it is not necessary to start with such a coarse grit. 60 grit will suffice in many cases.
The whole procedure is then repeated, using 60 grit. Once the drum sanding with 60 grit was complete, the edges were sanded with a 6" spinner/edger, also using 60 grit. Because there was no baseboard and I was planning to add wainscot, we were able to sand sufficiently close to the edges with the 12" x 18" vibrating pad after I screwed up this portion of the operation!
Mixing Saw Dust For Filler
To fill any gapping in the floor after the use of the 60 grit procedure, some of the sanding dust from the drum sander was mixed with the varnish to form a paste about the consistency and color of honey. After vacuuming, the floor was broad filled (trowel applied) with the paste.
12 hours later, the floor was drum-sanded with 80, then 100 grit. No diagonal sanding this time, only with the grain, because the floor was now flat. The paper is fastened to the floor-sander drum with a clamping bar which leaves a gap in the sanding surface and as the drum rotates. This gap leaves a series of ridges across the floor, called ‘skips' or ‘chatter marks'. The edges were sanded with the edger to 100 grit. To remove the chatter marks, a 12" x 18" square buff sander was used with 80, then 100 grit sheets, working along the grain. The sanding sheets were vibrated in the most peculiar way with an intermediary pad made of non-woven nylon. I was actually quite interested in using this particular machine until Ian pointed out it was overheating the way I was using it.
Floor Cleaned - First Coat Of Finish
The whole floor was then swept and vacuumed thoroughly and the first coat applied. To apply the coat we used an 18" roller with an 1/2" nap. A 1/4" nap would have been preferable, but was not available at the time. Before using the roller cover it was brushed thoroughly with a stiff brush to remove any loose hairs that would get into the finish. The urethane is applied across the grain, working in strips of approximately 4' wide. A 3" brush was used to cut in the edges prior to rolling.
Smooth Out Roller Marks
Once the 4' wide strip across the floor was finished, we returned to the start of the strip and, without adding urethane to the roller, gently crossed the wet urethane parallel to the grain to smooth out any roller marks. The action is: push the roller gently across the floor and lift it from the surface at the end of the stroke while still rolling to avoid leaving marks. After applying the coat, the roller and brush were wrapped tightly in plastic bags to keep for the following day to prevent hardening.
The first coat looked very good, with just a few hairs from the new roller (to be expected...this gets better the longer you use the roller) and some dimples in an area where the sun had shone on the floor and dried out the coat before it had a chance to settle.
Screening First Rough Coat Of Finish
The whole floor was cut back or screened lightly with an orbital sander, swept and vacuumed. A damp T-shirt was wrapped around a broom head and used as a tack-cloth to take up the last remaining speck of dust and the second coat was applied in the same way as the first, after masking off the sunny window.
Total cost for this operation was $606 for one week's rental of the three machines plus materials, 500 bucks for a round-trip ticket from England and a week of hard labor! Don't expect Ian to be available for pond hopping trips all the time. He has offered to answer consumer questions in e-mail by contacting him at the following link. Ian, thanks once again for sharing your knowledge and talents!
November 2005- We are sad to report, the world lost a great person, as Ian Gilham passed away.
Updated October 2014- Apologies for the small images. We’ve tried to reach the author of this story for larger ones, but had no success.
Added May 6, 2014
View the hardwoodfloorTV video that shows a botched square buff sander job fixed by professionals:
Added November 21. 2008
View the Clarke Sanding video overview that deals with:
• Preparation before sanding
• Which direction to sand can depend on condition of the floor
• Removing moldings
• Selecting sanding grits
• Avoid sanding errors. Fixes
• Operating a rotary floor buffer
• Tips on using the edger
• Scraping tips in those tight spots
• Final sanding before finish is applied