Sealing Wood Floors – is wood sealer necessary?

Q: Do I have to put on a “sealer” after sanding a hardwood floor or is it okay if I just use varnish? And for what reason are people sealing wood floors? Is wood sealer necessary?

A: That is a somewhat complicated answer. It depends what finishes and sealers they are using. If it is a solvent/oil based finish then I would fall back to the older architects recommendation to apply only polyurethane with the first coat cut with mineral spirits by 10% to aid in penetration. Since those days some sealers in this category have been developed which are actually polyurethane but designed as a first coat sealer.

One such product is Poloplaz fast dry sealer. Excellent product. Great penetration and pretty tough in it’s own right. Remember, it is polyurethane. In Toronto where I learned my trade, everyone is using lacquer as a sealer. Really bad idea and will give you a floor finish that will not stand up in the long run. In the water borne category some sealers are designed to help avoid a condition called side bonding and panelization. In this category, a sealer is fine to use. In solvent based, any sealer should be a polyurethane product.

Related Q: After staining Red Oak should you apply a sealer to keep the grain from lifting before applying the urethene?

A: You don’t actually need a sealer when applying stain. However, I do use a polyurethane sealer which penetrates the wood really well from Poloplaz. Before this type of sealer was created architects used to recommend cutting the first coat of polyurethane with 10% mineral spirits.

1 thought on “Sealing Wood Floors – is wood sealer necessary?”

  1. You need something to rvemoe the oil, like a standard de-greaser. Vinegar won’t do that, which is why the stench is still there. Use Lestoil straight out of the bottle pour it on the spill area, and scrub with a stiff bristle brush. Rinse by soaking with HOT water, then wipe. Repeat this a couple of times, then pour non-sudsing ammonia on the spot and scrub with the bristle brush again. You may need to repeat this process a couple of times. This will NOT be as effective if you don’t use a bristle brush. A sponge just isn’t going to get into all the tiny spaces. You can get odorless Omega 3 capsules and avoid this problem entirely.

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