Looking for suggestions on how to fix this...

I stained our oak floors a dark ebony-true black color with Minwax penetrating stain. I was actually pretty pleased with how they turned out and excited to finally get our poly on before we finish moving in at the end of the month.

I decided to use a lambswool applicator--I pulled out loose fibers, taped it it, vacuumed it, taped it some more, soaked it in mineral spirits and then let it air dry before using it to apply the poly (Minwax fast drying oil based poly in satin sheen). My vision is a bit poor, and it wasn't until I was 2/3 finished with the room that a glare on the floor let me see that there were lambswool fibers EVERYWHERE. I finished the room and let it dry--this was a few days ago.

I've read in other places to sand with 220 grit to help fix this...I've started sanding by hand and with a pole sander with 220 grit sheets and have now run into issues with the stain being lifted on some boards. It's irritating because I'm picky and was happy with the stain job, but at this point it's not enough to make me wanna go back and fully resand and restain the whole thing. But I also don't want to take anymore off...

Now the floor is white from the sanded poly which I expected, but it essentially looks like it has white "spots" all over the place from the sanded bumps/fibers --will this disappear if I put on another coat of poly?

I'm assuming I was maybe sanding too hard (I didn't think I was going too crazy)--but the sanding still doesn't seem to take care of the bumps from the fibers--let alone completely remove them.

I'm open to any and all suggestions on what to do at this point. I ordered a T-bar to finish my other two rooms because I'll probably lose it if I have to deal with fibers again.

If there's a way I can somehow salvage the stain job with a little meticulous spot treating (or whatever else) I'm all ears.
Thanks!!

Did you buff with steel wool after the stain dried? Steel wool polishes the grain raise after the stain has hardened so the surface is smooth. This may be the reason that you got so much shedding. Lambs wool is pretty fine. The second coat of finish will smooth out the surface. I use the buffer with a white pad that drives a used 100 grit screen to smooth the first coat of finish. Black floors will show more surface reflection than lighter colors, too.

I didn't buff at all after the stain dried--so maybe the raised grain from water popping and staining contributed to the shedding. Ugh. At least it's just one (small) room--hoping to figure out the best way to move on from here before I do the others.

I'm concerned about any sanding/buffing now though because some of the stain was taken off after I attempted to sand out the fibers with 220 grit (predominately by hand). After vacuuming it does look considerably better now as far as the bumps and fibers go, but it also revealed more areas than I realized where the stain has been rubbed out.

Would the wood at this point even accept more stain in these areas? Should I consider tinting the poly with stain or using one of the minwax repair markers?

If you dampen the floor with either water or paint thinner you can see how much stain you have worn off. It may seem like some has worn off after the fine sandpapering. The wood has been sealed now so it will not absorb stain. If you do wipe it on, all should wipe off if you wipe firmly. You can color the surface by carefully leaving some stain on the floor as you wipe off. This stain must harden for some time or it will buff off with steel wool, if you need to darken any spots. A coat of finish will not lift the hardened stain and will stick, keeping the color. Touch up felt pens may work, but may be lifted with the next coat of finish, if you do need to add color.
Popping the grain adds extra color, but the high, rough surface will wear differently than a smooth surface. Using sandpaper between coats is not as good as smoothing with steel wool which is not as aggressive to the surface.
The more coats of poly that you add will result in a more yellow coating. Water-based finishes do not add the yellow that oil based poly will show as it cures.
Some people do like the yellow, however. It can also have a green tint as it has cured.

Thanks for the suggestions. When I was trying to sand out the fibers the sandpaper took off the dark stain to the point where I could see the much lighter wood. This was for the most part along edges/ends of boards. I'll switch to using the fine steel wool for abrading any future poly layers.

Should I expect that the oil poly would still take on a yellow tinge despite the near black coloring of the stain?

It sounds paradoxical to me, but would putting a water based poly over a layer of oil based poly (or oil based Minwax stain) be okay and cure properly? If so, is there a particular water based poly that you'd recommend that would be safe and good to use with Minwax penetrating stain/Minwaxy fast drying oil poly?

Thanks!!

The coating does influence the color, but it happens slowly. Dark colors with black in them sometimes have a blue tint that the poly makes look green. It is still dark.
Water-based finishes are pretty clear, although some have a very light yellow color after three coats.
Water-based poly adheres to stain, which acts as the sealer. The stain needs to be dry. Find a local supplier and follow the directions on the can or call the phone number on the can for best results.

I realize that this is a very old post but the information is helpful. I'm wondering what grade steel wool would be best for buffing in order to remove the sheep's wool residue from polyurethane finish - 0000?

I purchased a sheep's wool applicator and am having second thoughts about using it due to the issue with fibers shedding. Would it be better to use a rag to apply stain to prevent the problem altogether? If so, what type of rag is preferred? TIA

Fine sandpaper will smooth the fibers. #2 steel wool can be used after the stain has dried to help remove any stain residue from the surface, after it has hardened, before the first coat of finish.
Use rags to apply, and then remove the excess stain before it dries.
Lambswool can have some fibers and usually will all come out with the first coat.
The second coat will have few or no fibers that you would notice. Cleaning after the first coat of finish is applied will also help to remove loose fibers. Too bad no one sells used, but lean lambs wool applicators. They become more valuable after the first use.