Hi Everyone. I’m wondering if anyone has any experience with this, given the impressive range of knowledge here.
I just put in a NEW unfinished hardwood floor, and I’m getting ready to finish it. As it’s maple, and I wanted no stain, I followed the urethane manufacturer’s instructions and put down a seal coat prior to the urethane. I used Minwax sanding sealer, as it’s a brand I have had good luck with.
It’s very difficult to see the coverage once dry, but I feel like I missed a couple of spots. I’m obsessing about it. The sealer instructions say only one coat is needed, but don’t say a second coat is ill-advised. I don’t want a missed spot to show through the urethane as a blotch- the urethane will almost certainly look different over an unsealed spot.
I would think it would be ok to put on a light second coat of sealer, just to be sure. But I wondered if anyone here has knowledge that this is or is not a good idea.
(FWIW, this is my first time finishing a floor, though I have installed hardwood before and I have a LOT of experience finishing furniture and cabinets, and frankly I think I’m pretty good at it)
I wouldn’t. The additional sealer will interfere with the finish. You could try to find the spots you missed by shining a light on the wood at a low angle, and adding a thin coat of sealer to those spots. Unfortunately, you may never know any of the effect of this for some time as the wood darkens unevenly. Fortunately, Maple is very hard and tight grained so it should not absorb much sealer or urethane and whatever the problems there are will be minimized.
Having experience finishing furniture and cabinetry, you have probably already tried to see if you can tell any difference by touch in areas you suspect might have no sealer? (Small wood fibers protruding from the surface might feel stiffer or snaggier in a sealed area, and conversely feel fuzzy or unnoticeable in an unsealed area?)
That’s what’s making me obsess. There are two spots that seem to have a different sheen, but don’t feel different. But that could be an artifact of the thickness or the application tool in that spot.
If these are tiny spots then it doesn’t really matter. If they are large enough apply a little bit of sealer to a small area near the edge of a spot and see if the wood looks the same as the adjoining sealed area after the sealer dries.
If you are doing a decent job of sanding after each coat, I don’t think a second coat will hurt at all.
But I also doubt you’ll see a noticeable difference in the wood if you missed a couple spots. Maple is much more uniform than something like oak, but it still has natural variations that I think would swamp out any differences in the sealer coat.
I wouldn’t worry about it. The beauty of natural wood is that it’s not completely uniform and there are variations. It adds character to a room. Also note that if some of the floor gets direct sunlight and some doesn’t, the parts will age differently anyway.
One of my problems with manufactured flooring is it’s too uniform and looks unnatural.
I would determine if any areas were missed but mopping down a light coat of water. Missed areas should either appear darker than the coated areas because the maple will absorb more water and also dry slower.
I am a little surprised you decided to use a sealer. Usually with maple, a sealer is needed before staining to avoid a blotchy appearance due to sapwood but you wish to stay with a more natural appearance without any stain. Unless you’re using a stained urethane.
I debated long and hard over whether or not to use the sealer. But every single urethane manufacturer recommended that if one is not staining, then one shall use a sealer. I’ve never used a sealer on my other projects, some of which were maple with top coats and no stain. As a floor is under much more strain and abuse than most furniture I thought there might be a good reason. When in doubt, follow the directions.
ETA: The water test is a good idea. I should have thought of that. The sealer is basically a very light urethane, as far as I can tell, and water will bead up where it’s present.
You’re quite right about the floor receiving abuse. On several furniture projects, to add strength and durability to the finish, I apply a base coat of urethane with a high gloss finish because high glass is the most durable. I top coat with my desired urethane of either semi-gloss or satin depending upon preference.
Although it adds to the trouble and expense and possibly adding a day to the process, I would apply a base coat of high gloss followed by 2 coats of my preferred gloss. Lightly sand or steel wool before the final coat. It should add years to the finish lifespan.
I have not finished any floors my self but I manage projects that involve site finishing hardwood floors. This is always with well established professionals and they universally use Bona products (usually Traffic). It is a two part water based product, not urethane as far as I am aware. Quick hardening, and easy to work with.
I haven’t heard of ‘sealer’ being used, but on unstained floors they usually recommend a coat of oil / natural stain to enhance the grain. I am guessing thus is the purpose of the sealer?
Maple is terrible at taking stain, I hate the stuff. Generally if I am looking for inconsistencies in surface prep, such as glue or finger prints, a wipe with a damp rag will reveal problem areas. This was mentioned above, and my only caveat is to make damn sure it has a chance to completely dry before finishing with an oil based urethane.
Maple is very light, in most grades has lots of little flaws, I doubt an area of missed sealer will really make a big impact.
Well, I just thought you might like to know the final result.
I sanded the floor (per the instructions) and took a long and careful look at it. I decided that I was being crazy and moved on the the polyurethane (using Bona 350, by the way; I too am aware of its reputation*). One coat in, I’m very happy with how it looks. And I’m a pretty tough critic of my own work.
*For FluffyBob’s benefit, the Bona Sport Poly 350 instructions indicate that a sealer should be used if not staining the floor, and Bona manufactures this product. However, NONE of the several local Bona suppliers carry it; I suspect it’s not often used, despite the instructions.
Interesting. I know my vendors use the Bona stains, because they always comment that there is a limited selection when homeowners are signing off on the stain. I assume its a warranty issue. When I had my floor done - natural oak- they recommended the natural ‘stain’, but did not indicate it was required, I assume it was the sealer.
