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refinishing hardwood floors

I recently refinished the hardwood (oak) floors in my newly purchased home. I did the basics; drum sand, clean, stain and seal. I used boiled linseed oil for the stain, and a water based poly-acrylic for the seal. The floors looked amazing when the job was complete, however they are developing black stains throughout floor. I think it's because of the polyacrylic sealer, but would like others advice on how to remedy this.. .

Re: refinishing hardwood floors

The black stains could very well be mildew. Mildew feeds off of linseed oil and creates these black stains. I have only heard of this on the outside of houses if people stain their house with a linseed oil-base stain. This is what leads me to think that it is mildew (caused by the stain you used) and NOT the acrylic polyurethane.

In order to fix this problem, sand the floor again, use bleach or another mildew-killing product. Without killing the mildew, the stain will remain or reappear because it is an organism. Restain the floor with regular oil-base stain or shellac, and seal the floor with a polyurethane (acrylic would work again, but it dries fast and could be tricky to work with when sealing a floor). If you use shellac, however, a sealer is not needed.

Re: refinishing hardwood floors

Linseed-oil finishes should be outlawed...they're crap for protection, and take forever to dry. This may be part of the problem...Linseed not completely dried-out, then covered with a water-based finish.
Plus, the compatibility between LO & Water-based poly's is questionable at best.

IMO also, above poster is correct.
Sand the stuff off, and re-do.
Make sure the topcoats of Poly are OK for FLOORS!!
Minwax has a couple separate Polycrylics.

>>> Plus...Water-Polys dry to thinner coats than oils. If it were my house...4 coats MINIMUM of Polycrylic...preferable 6 to start out!!
Read those details!!

Zar-Ultra is a great oil for floors. 3 or 4 coats, and you'll have gorgeous floors. Let-'em harden-off for a WEEK or more b4 heavy pieces go back in.

(Pretend you've never heard of Linseed-oil!)


Re: refinishing hardwood floors


Any chance of a couple/few pics?

Re: refinishing hardwood floors

If you use shellac as a sealer in the propcess with polyurethanes, make sure that it is de-waxed. This sealer is sometimes called universal sealer because it is compatible with almost all finishes.

My personal preference is for oil based urethane. It dries harder. Many of the floor urethanes are reinforced with aluminum silicates, the same tough stuff sandpaper is made from. It gives greater wear. All oil urethanes do have a slight amber tone which should not be a problem with warm natural toned stains. Also, when using urethanes, I like to follow the directions on the can to the hilt. Urethanes do not like to stick to themselves, so it is imperitive that you follow the directions as to re-coating. There is usually a window of re-coating - not before so many hours and not later than so many hours. Often a light sanding is recommended between coats, especially after the first coat. The first coat acts as kind of a sanding sealer and raises the grain slightly.

Just curious, why did you choose a linseed oil stain?

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