A: It really sounds to me that they missed seeing the area they had missed with the sander and when they put on the stain, of course, it would not take. I doubt it is because they cannot get the stain out. You can and no doubt will still have traces of white stain in the heavy grain. But an entire patch? It sounds to me that they had a little bit of bad luck here. It can be very difficult to see the white stain with, no doubt a non yellowing water based coating on top next to freshly sanded wood. Very difficult. And if you don't spot it, then, you see the result. I don't know how far they have gone with the job so far, but really, they need to pull out their edger and orbital sander and do those spots down to bare wood if it is possible or depending how large an area it is, use a hand scraper. They have to remove the finish and stain. There was possibly a dip in the floor and the sander went right over the area and missed it completely, and since it is such a light colour, they missed seeing it. I don't know what procedure they used to apply the stain, or how dark the colour is but it can also help as far as penetration by wetting the freshly sanded wood, letting it dry and then applying the stain. This is called "popping" the grain. The stain will penetrate deeper and result in a darker colour. However, the wood has to be exposed. In other words, the finish and white stain must be removed. These stains set up pretty quickly, and there really isn't much penetration into the wood at all with pastels. They missed the spot.

