Finishing maple flooring: stain sealer + water poly?
Hi all,
I installed maple flooring in the kitchen and need to finish it. One criticism of water-based polyurethane is that it does not soak into the wood, making the bond something less than ideal. Another is that the water-based finish tends to raise the grain more than an oil based finish. Might both problems be solved by using a stain sealer as the first coat? As I understand it, a stain sealer is just a very thinned-out oil based polyurethane.
Thanks,
Scott
Replies
You can get water based sealers, I've used it as a first floor coat partly because it cures
so fast you don't lose much time on the first coat. Between coats of poly I'd scuff sand
with a half sheet orbital pad sander. The grain does raise but is easily knocked down.
You should scuff sand between every coat any way, oil or water. That goes for floors or
any other wood work for best results. Scuff sanding makes a nicer looking coat and
supposedly allows for better adherence. My opinion is that hardness/thickness of the
finish is the biggest concern on floors. In either type of polyurethane that protective
layer is just a thin layer of plastic.
Most poly is used as a coating not as a penetrating sealer. Do not use sand sealer as it is soft and will not resist scratching as well as starting with poly. Sand sealer is good for furniture, but not flooring. Raised grain is not an issue at all. Typically the grain raises once and that is it. Most flooring finishers will water pop the floor before stain. It’s kind of conflicting with common sense as water on wood sounds bad. It actually works really well. If you wet the floor before stain it opens all the pores of the wood which allows for deep and more even stain and sealer penetration. So with water based we water pop, dry time, apply stain, apply first coat of poly. The finish will feel terrible and you’ll think that you made a mistake, but you’ll buff the first coat which will take care of raised grain. After applying following coats of finish it will all work out.
I prefer the water based poly. Bona Kemi in particular, but there are plenty good brands.
a. If water based doesn't soak deep enough into the wood and therefore doesn't provide a proper bond, how do you account for the raised grain?
b. If the sealer is peeling off, the raw wood flooring was sanded to too high a grit and probably applied too thick. This is true for water AND oil based sealers.
c. Yes, water based poly does raise the grain a bit but since you're gonna screen between coats, it becomes smooth and flat again.
d. Apply thin coats. It looks better and shows off the texture of the floor.
Hope this helps,
Frankie
Water based Sealers really works well and they really cure so fast.