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Hello everyone,
I am installing an MDF Floor in a customers home. The design is 16″x16″ squares (1/8″ spaces similar to grout lines for tile). The finish desired is a satin hue oil based Polyurethane.I have sanded the floor with 150 grit and swept all of the dust. I made a sample with three coats of finish and it looks great. When I applied the Poly-u to the floor; it seemed to show lines in the MDF that were not evident prior to the poly. I used acetone on a small section to see if it would stain or effect the lamination as water would. It did seem to leave streaks. Does anyone have any advise on this topic? Thanks Scott.
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Ahhh, MDF? As flooring? Which you sanded??? (The dust oughta settle by the next nuclear winter
Do you mean straight ol' medium density fiberboard? That MDF?
Never occured to me it could be used as flooring.
Once you get the finish issues worked out, maybe you could keep us posted on it's wear characteristics.
For all I know, maybe it's the cat's meow for inexpensive flooring.
*As Bob said, Keep Us Posted!what did you fill the "grout" gaps withhow did you attach to floorYou have sparked my interest
*Scott,This is interesting. I have used 1/8" masonite as a border on curved floor designs and around medallions. Have never thought of it as a floor though. How did you fasten it down?...screws and plugs? What are the "grout lines" filled with?Maybe you could drop down a grit, say 120 then finish with 150. Maybe try water based poly as it has a clear finish. Keep us posted.Rich
*Shoeman,Look at our post times. Thats too weird.Rich
*Scott, you mentioned that the acetone left some staining. Could you walk over the floor a few times sprinkling drops of acetone to give the floor some kind of motted pattern that would help hide the other undesireable lines. A sort of faux finish that would add depth? outside the box
*Rich,perhaps you also are a great mindthinking alike and all
*Scott - As a recycled material, some MDF contains metal particles from miscellaneous fasteners that get into the recycling process, although I think there may be some brands of MDF that are certified 'metal-free' - not sure.Maybe the scratches were caused by particles eroded in the sanding process, or afterwards.Jeff
*Scott,I've noticed that when finishing MDF, sanded areas will absorb more finish than unsanded areas. Maybe you need to seal with something before finishing?
*Did you sand your sample before applying the three coats of finish to it...in other words, did you treat the sample exactly the same as the floor?When MDF is processed, it comes out with a "skin" on it. The surface skin on the old, heavy MDF is much more durable than the newer, lightweight, Trupan version.I can't see the lightweight stuff holding up as a floor. Actually, I have trouble picturing the heavier stuff, too.What thickness are you using?The only other advice I can think of is to bring the grout up to the top edge of each tile. Any MDF that stands proud of the grout...even if it's a 16th of an inch...stands a chance of being caught by a heel or a chair leg and fracturing. It's possible the tile edges could be strengthened by applying poly to the tile sides as well.
*Hey, I appreciate the info. It's 3/4". I had my doubts as well but have talked to others who have used the same application. They sware by it. The poly will seal the mdf, also the edges. That is interesting about the "skin" though. Makes sense. The squares are screwed and glued to the underlayment(3/4" T&G OSB).the 16" squares are actually fastened to the floor joists. We used pan head Stainless in the corners. When the floor was sanded we hit the edges to aviod higher corners. As for the "grout joints" our thoughts were to use a colored latex caulk. Sanded grout mixed with latex even seemed as if it might crack.
*Scott,I guess it's too late now that it's installed, but a 1/4" wide frame around each square made up of a contrasting species of wood might look good. Like a bunch of custom parquets. I'm still interested in how it wears over the long term. My concern would be chipping and tearing along the edges.That sounds like a lot of meticulous caulking.Good luck,Rich
*I've used MDF as a flooring material for years and have found it to be very durable. Here are a few pointers that may help you. Make sure to ease all edges and corners before installing tiles or strips.b ....never sand the surface until it has been b prepared with a sealer...I use a fast-drying polyurethane which I thin down with lacquer thinner (2 parts urethane to 1 part thinner) the thinner will give you good penetration which will add to the overall durability of the floor and it will prevent any bleeding through of processing marks in the MDF. I stay away from waterbase products as they raise the fibres and bring out any defects or processing marks in the MDF. This should be done before the pieces are installed. Brush on the urethane, let it sit for a minute or two on each tile and wipe them dry....Let this finish thoroughly dry overnight. You can now sand the surface of the peices with 220 sandpaper The tiles can now be finished with the desired top coat. Waterbase urethanes work well over this sealer.To glue down MDF flooring I have found that ceramic tile mastic works best....use it the same as you would laying ceramic tiles....I use non sanded grout to fill between tiles and a sealerAnother note here is that I always apply the sealer to both sides and all edges of the tile....The back of the tiles do not have to be sandedMDF comes in several grades...D grade may have defects like broken corners,press marks,oil marks,varying thicknesses and delaminating...Shop grade may have varying color and fibre sizes in the panel.... Premium grade will be consistent in color and texture as long as sheets are from the same batch. Most MDF manufacturers here mark their panels with a batch number and exact time of processing on the edge of each panel. If you put a clear finish on your MDF it is best to get panels from the same batch and processing time