Don't feel bad. What you're trying to do does require a lot of finesse and without the experience it's a learning process for sure. If you can figure it out you'll definitely save some money. It's especially fun when you can go to a second hand store and find a great piece of furniture that's cheap and unwanted because the finish is in bad shape. Okay, so you're at the point of over sanding and cutting into the underlying stain. I'm assuming the color is different and it's not just the white haze caused by sanding on varnish? It's probably still possible to blend the lighter spots back in but I'm not sure you'd want to purchase the supplies to try the techniques out. I sometimes use touch up markers from a commercial finish supplier or raw pigments and dyes mixed with thinned shellac. You'd have to invest $50+ in supplies to attempt a technique that is difficult even for a pro and may fail and the supplies will likely go to waste afterwards. Now if I were working on that table, I'm guessing I'd be swinging into full strip and refinish mode. The reason is that you say your husband's poly is cloudy in spots. If that was there before you started sanding then it could be water damage. Otherwise, it's almost certainly an indication that the finish has separated from the surface below. Trying to finish over the top of that would be a waste of time. No, you don't have to sand all the finish off. It's also really difficult to sand off an old finish and end up with nice, even coloring afterwards. Using chemical strippers is a lot easier but also a little intimidating if you've not done it before. For starters, you need to do it outside because you don't have the equipment to ventilate the fumes. Secondly, you'll need to invest in $30 of gloves, scrapers, brushes and other supplies if you don't have them already. This will also remove most of the stain and require matching the new finish to the chairs. Your best bet is to first see if there's a reputable shop in your area that is setup with a flow-over strip system, outsource the stripping but do the refinish yourself. Chances are, it'll cost you almost as much to get supplies to get started with the chemicals as it will to pay a professional to do that part. If you do that job yourself, you'll need plastic drop cloth, heavy nitrile or neoprene gloves (probably multiple pairs unless you find the good ones), some scrub brushes, plastic putty knives and half a dozen pieces of Scotch Brite. That's in addition to the stripper and the solvent required to wash away the residue. I use methylene chloride stripper but it's potent stuff. Breathing it is bad and it will burn skin within seconds of contact. Plenty of ventilation is a must when using that and since some companies add flammable solvent to the mix, explosion-proof ventilation is a must. That means work outdoors or own professional finishing equipment. The citrus-based and soy based strippers work fine but are slower and in my experience, more expensive. 3M Safest Stripper is very slow but effective when used properly and can be used indoors. Downsides are water content will make the wood moist and it was more expensive than the others the last time I checked. If after reading that, you prefer the hard, dusty work of sanding, then my approach would be to get good coated (minimizes clogging) sandpaper from an automotive finish supplier and start with 80 grit on flat surfaces. Don't bear down on the paper, just use even, smooth strokes and let the paper do the cutting. Stop using the 80 as soon as the wood starts showing through and move to 100 to get most of the remainder off. 120 is good for cleaning off the last residue and you can jump to 220 to prepare for stain. Always sand with the grain of the wood. For profiles and other details, I'd not start below 150 grit. Be careful sanding on that top though. It may be a thin veneer so avoid removing any wood. and that's another reason I use chemicals instead of sandpaper.

Finally got him to bring the floor contractor back to our house to discuss. Between the two of these clowns, they determined in their own minds that we changed our minds from 2 coats to 3 on the ground floor in mid job, they changed up what they put on the 2 nd and 3rd. All Glitsa, that's all he uses. I couldn't get the 2 of them to understand that both floors were completed at the same time, with 2 coats and it was well after that when we asked for the 3rd coat downstairs for additional wear protection. I tracked all that down and forwarded his change order ($1000) from December. The initial 2 were July 2012 before. They never did match. Now he says he can put Glitsa in a gloss on top, but that we have to wait a month for the July 2013 rework to cure. He would prefer 6 weeks. Real, or BS? What do you think? Again, that you in advance.

Sorry if I'm hijacking this thread, but you guys seem to know a lot about piano finishes. My hubby, being helpful, has used a myriad of furniture polishes on my Yamaha grand. It used to have a satin finish but now has greasy streaks, etc. I remember once a repairman, who did a beautiful job of fixing a ding from a move, using something like paint thinner for the final finish - along with very fine steel wool. Was it really paint thinner? I am not going there with the steel wool, but would paint thinner get the yucky stuff of the finish or would I be asking for trouble? The piano is at least 34 years old.

@HU-121060632 The pro needed to knock down the grain after the primer. The grain raise needs to be addressed before the 2 coats of finish are added. Another issue is probably the lack of buffing before the last coat. A well trained pro will do a quick once over just before the final coat is applied. This offers a beautiful, smooth finish after the last coat is applied. It really is the sign of a professional at work. The other issue is Mega One. It is an 'OK' finish. It is easy to work with but nothing 'special' other than the VOC content. A freshly finished floor - even with the quick curing Bona products - takes almost a month to mature. Mega One is NOT known for it's toughness. It is know for easy use and easy budget implications. If you wanted tough(er) then the Bona Traffic would have been the minimum. And even now, Bona has the Traffic HD line = UBER super-duper tough. But the price tag is UBER expensive (like 3 times more expensive than Mega One). Feel free to reach out to your pro to see if a quick buff and coat with a third coat of finish will do the trick. You will have to pay for the cost of the material for the third coat = Bona Mega One costs. The cost of the buffing/light sanding SHOULD HAVE BEEN included in the original quote. That cost (ie. labour) can be negotiated.