Lines and streaks in tung oil finish

Q: We have an old home that needed new floors. We decided to put down pine, wide plank floors. They are very beautiful, but the manufacturer had us use tung oil on them. Through the process I found out there were two types of oil: one goes on first and one goes second. Well, by that point, we had started putting the second one on before we had two coats of the first. We then just had to go with what we had done.

The problem I have now is that the floors are uneven in color and you can see lines and streaks in the floor. Not to mention they are impossible to keep looking clean. You can see every footprint and so on. What can we do?

I would like to try and go with urethane. We have been told we can put it over what we have. I am scared to death to make a move and ruin them more, or worse.

These floors took well over half of our budget and they look terrible.

A: I would have someone come in, polish them with a fine abrasive and apply a couple of coats of polyurethane. Tung oil, in and of itself, isn’t a practical finish for a floor. If you had used Waterlox which has tung oil as one of the 5 main ingredients you would have had much better results.

Unfinished bald spots in several rooms

Q: We have just bought a house and had some new wood floors put down. We showed up the night we were allowed to walk on the wood, to inspect the job. We have found about 12 bald spots in several rooms, as well as a square nail back sticking out of a board in the middle of our dining room. I called the contractor and he said he’d saw the nail and will sink it and cover with putty. He couldn’t believe we saw bald spots (some 5 inches long). He says he’ll just patch them up and it’s no problem.

I feel we have a big problem. Should we insist he polyurethane the whole floor over again and move in later? If so, how many coats should we insist on? I don’t want these floors to age prematurely because they have too thin a coat. Also, I can feel the grain texture over multiple areas of the floor, which makes me think the poly was put on too thin. It is suppose to be 3 coats now.

A: It sounds like the floor needs to be buffed down and another coat of finish applied. Most coatings have a spread rate of 500 feet per gallon. Given so many spots he missed with the finish, I think a full buff and coat is really the only way to fix it up. Buffing with a fine abrasive should knock down any rough spots or grain raise.

Related Q: I had my oak hardwood floors sanded down and refinished with polyurethane (oil). I’ve noticed that some spots along the walls have been missed during the finishing part with polyurethane. It looks a bit dull in those spots. Would another coat fix the issue?

A: Yes, another coat will fix the missed spots but the floor will have to be buffed down again to make sure you have good adhesion.

A few spots poly will not stick to

Q: I have been using oil based polyurethane to finish a bar top. I have 6 coats of poly over 1 coat sanding sealer and one coat stain. There are a few spots, one is about the size of a dime, that the poly will not stick no matter what I do. I have tried sanding just in those spots a little more than the rest, between the coats of poly, but it doesn’t make any difference in how the poly sticks.

What really confuses me is that the rest of the bar, the sides and the arm rest, do not have any of these spots, it is just the top. Do you have any advice on what to do to make the poly stick to those spots?

A: I would think this has to be caused either by some sort of extractive in the wood itself or a contaminant on the bar top from outside sources which hasn’t been removed. Try wiping the spot down with denatured alcohol to remove the contaminant. Or apply a small amount of de-waxed shellac (Zinsser seal coat) to those areas where this is occurring.

Finish eroding in a bubble-like pattern in some spots

Q: We have a four year old floor and around the fridge and some cabinets we have found places where the finish is eroding in a bubble-like pattern. We just had the whole floor refinished and that day the bubbles returned. They are not like air bubbles but are the same shape. What are they and how do I get rid of them?

A: My guess is that when the floor finish was applied the fan on the refrigerator started to blow air across the floor, causing these “fish eye” bubbles to form. The only thing that can be done is to rub them down with a fine abrasive and apply a fresh, thin coat of finish to the entire affected board.

Removing sealed grit from finish

Q: I have a BR 111 Triangulo Santos Mahogany wood floor. I use Bona Kemi products on the floor, which are safe. However, I put the refresher on the floor with a less than clean rag and ended up sealing grit, etc., in the floor. Is there a safe way, below hiring a professional, to take the refresher off and begin again?

A: I have not used their refresher product. I would suggest lightly abrading the coating with a 3M maroon pad, clean it well and re-apply according to their directions.

Finish peeling in sporadic areas

Q: The old owners refinished our floor but they are peeling, in odd and sporadic areas all over the house. Can the areas be fixed or do I have to redo all the floors?

A: I would definitely recommend a complete re-sand and finish. You are either dealing with a contamination issue between the coats of finish, or improper preparation between coats to ensure adhesion. What you apply on top of this now will only be as sound as the coatings it is sitting on, which by your comments is not stable, but peeling throughout.

Peeling off someone’s hack job coat of polyurethane

Q: We recently bought a small condominium that has an engineered (5 layer) maple hardwood floor. Someone attempted to refinish the original satin finish with a high gloss polyurethane. The shiny top layer is peeling off in sheets all over the floor. My question is, is there any way to “buff” off the shiny coat and get back to the original satin finish WITHOUT having to sand and re-finish the entire floor? The places where the new shiny coat have peeled off reveal a perfectly fine original satin finish which is what we would like to get back. Thanks.

A: I can’t see buffing this off. For example, if you used a car paint finish buffer you would face the risk of flakes of polyurethane getting under the pad and scratching the original finish. Unless you can patiently peel off the gloss coating a situation like this generally requires totally sanding the floor.

Pit marks after buff and coat of prefinished floor

Q: I had a 10 yr old glossy Bruce 3/4″ prefinished hardwoood floor screened and buffed a satin finish, now it looks and feels like there are pit marks on the floor. What could this be from and can it be fixed?

A: It is very difficult to impossible to adequately screen the coatings on these floors given their abrasion resistance. This is why a chemical treatment has been developed to gain adhesion. So I would be concerned about this coating peeling off at some point. What this pitting is I don’t know. Was the floor not thoroughly cleaned before the finish was applied?

Follow-up: I don’t know if it was cleaned properly. The same company did the same procedure, screened and buffed, three other rooms in the house and they all came out awesome; the difference is they were not prefinished.

Since the room involved is my daughters and she just moved back into it, she does not want to go through the aggravation of moving out of the room again, so will live with the floor as is for now. I guess it can be called the distressed look! Thank you for your reply.

Delaminating finish and stain coming up as well

Q: We bought a foreclosure a year ago which had lots of urine stains on the wood. The flooring contractor sanded everything down and patched where needed. The bare floors looked great. We had them use a dark stain and gloss water based poly finish. Again, everything looked great when done. A couple weeks later, we noticed a small round spot where the poly had come off. More spots appeared over the next several months. In most cases, the stain seemed to come up as well. Some spots were tiny, some up to 1 1/2 inches, mostly round but not all. They sanded the floors down and redid everything. 2 Weeks later, I’ve found 2 spots where it is starting again. What could be causing this?

A: This is very strange. Delaminating finish is one issue which can be explained by some type of contaminant on the floor or between coats which prevents adhesion. Stain coming off too is a different animal altogether because the stain does penetrate into the wood surface a little bit. It isn’t just something that sits on top of the wood like a coating, unless he used a tinted polyurethane. Can you tell me what stain he used?

Follow-up Q: Unfortunately not. When my contractor went to have the floors redone, the sub claimed not to have a record of the stain used initially. It was not a tinted poly. It was supposed to be two coats of ebony stain (brand not known), but we found a plain silver can afterwards that had written on it “plus 12 oz. black”. When they redid the floors, the color came out much lighter. My contractor had scheduled a different sub to come in and strip them down again and try to get the color right, but now we have these spots coming up again and don’t know what to do to prevent that. The original contractor argued that some outside contaminant might be being brought in either on our shoes or the dog’s paws. While the ongoing nature of it and the fact that the spots are mainly in traffic areas would tend to support this, the fact the most of the spots were perfectly round doesn’t, plus I don’t know what we could be tracking in that could do this. We don’t have any contact with anything that caustic or acidic. Also, there have not been any problems on the stairs, upstairs, or master bedroom, which are all entirely new wood. Is there anything they could have used on the old floors that would cause this?

A: While I’m not suggesting this caused the problem, I’m not a big fan of applying two coats of stain, especially when using very dark, heavily pigmented stains with more pigment added. If I want to achieve a darker version of the colour I will water pop the floor, which simply means wetting the surface and letting it dry to open the surface and allow better penetration. I tend to think as was mentioned, that a contaminant is being introduced. I was called in to refinish maple floors that somebody made a real mess of. Everything I did looked excellent until I applied the finish which still looked amazing except in areas where the finish was being repelled. The home owner turned his garage into a Harley man cave with plastic tiles on the floor. I walked back and forth constantly over this floor to get to my trailer. I asked if he treated these tiles with anything. Yes, Honda spray. And he had renewed the spray two days before I started work. So, that was the culprit. I was able to polish the floors, wet buffing with Poloplaz Tie Tac which removed the contaminant. Then I screened a recoated. I’m no so sure this will work for you because in this case your finish is peeling off. In my case the finish was repelled and didn’t form a film over the areas of contamination.

Follow-up Q: So that was something that was being tracked in during the refinishing process before the poly was applied?

They are talking about something being tracked on an ongoing basis after everything was finished. That’s part of the issue – that the de-lamination has gone on over a period of months. What type of situation could cause that?

A: When the finish is delaminating and pulling away from what is beneath it, clearly contaminants on the surface are irrelevant. The problem is what is beneath the finish. Someone or something could have walked a contaminant across the freshly sanded floor or over the stained floor before any finish was applied.

Another possibility I thought of as the previous email was leaving is the slight possibility, if the workers who did the job wore knee pads that had something on them. But you say two different crews did the work with the same results so this possibility is stretching the limits of probability. I generally try to look for the simplest, most obvious explanation first: something finding it’s way onto the floor before the finish was applied. That contaminant could be the heavily pigmented stain itself, especially if they used a water borne finish and the stain was not 100% dry. The solvents from the stain would not allow adhesion.

Tons of little scratch marks on wood floor

Q: Hello, I recently sanded down to bare red oak floors Wednesday. I put down the first coat of oil based high build gloss poly Wednesday night. All looked decent. I did a light sanding with 150 grit this morning and cleaned and re-coat. I look now and I see tons of little scratch marks all over. I do not know what to do at this point to get rid of the scratches if anything. Please help. Thank you.

A: You will need to buff it all down and apply another coat. I would recommend a lower shine, say satin which looks very nice and is easy on the eyes. Gloss is particularly unforgiving when it comes to things like little scratches.

Follow-up: OK. Thank you. I was going to use 220 grit in Palm sander then reapply with satin.

A: You should be fine. Just make sure you thoroughly buff the entire floor. 220 is more than fine enough. I often use 180 grit with no issues.

Follow-up Q: Okay thank you. Is buffing different than sanding using 220 grit sandpaper?

A: Not necessarily, though sanding generally can invoke the idea of removing all finish to clean wood. Buffing or lightly sanding with the intent of scuffing or scratching the existing finish coat to gain adhesion is what we are aiming for. Accomplished with the finest abrasive that will do the job, thereby minimizing visible scratches.

Related Q: Hello. We at redoing our hardwood floors for the first time. After sanding and cleaning we applied old masters penetrating stain with a rag. Then we applied satin polyurethane with a brush. After the poly dried we noticed several little bubbles that we sanded down with 120 grit sandpaper. Now we have sanding marks all over the floors and I am worried that if we apply another coat of poly the marks will show through. How can we fix this before we put another coat of poly on? Thanks!

A: When applying more than one coat of polyurethane you must sand or buff between coats with a fine abrasive to gain adhesion between coats. So scratching is part of the process. The idea is to have scratches fine enough that a good finish will cover and hide them. After thoroughly buffing the entire floor, being careful not to cut into the stain, clean up and apply another coat following the spread rate of the finish which is generally 500 sq. feet per gallon. You may want to use a top quality finish such as Poloplaz Primero satin. It’s is a great product to apply with a 3/8 or 1/4 pile roller.

 

Black spots appearing after refinishing

Q: I just had my oak engineered floors refinished by professionals. Everything looked great. Days after black spots started appearing in one room. The spots are getting bigger and more are appearing each day. This room is on a second floor, so no water problem.

A: I can only make a guess on this. It sounds like water but as you say water is not involved. Then I would suggest a fungus, probably present right from manufacturing. Perhaps they used a water based finish which re activated it. I would call the guys back and have them assess this. You can also contact the National Wood Flooring Association who do have inspectors. They also have a huge repository of information and have likely come across this issue before.

If you take this course, I would be grateful to know what is concluded.

2nd Coat of polyurethane rough and grainy

Q: We sanded, stained and oil based polyurethaned a wood floor with 2 coats. We did not sand between 1st and second coat. 2nd Coat dried rough and grainy looking. We sanded second coat. Smooth but still grainy looking. Do we need to start over? All 5 rooms look like this (put 1st coat down day 1 and put 2nd coat down the next day). Have not applied 3rd coat. Can this be fixed without sanding down to bare wood again. Would attach picture if I could.

A: Roughness can be caused by rough preparation in sanding, grain raise or debris in the finish for example. A light but thorough sanding with fine abrasive should take care of this issue. The floor needs to be completely vacuumed and wiped down to remove all dust and debris. I’m not certain what you mean by grainy. I’ll take a guess. If you are working with oak for example that has a heavy grain pattern the finish will soak into that much more than the surrounding wood. The grain is much softer. Finishes have a spread rate they should be applied at, generally about 500 sq. feet per gallon. Applying thick coats is a bad idea. The heavy grain is really part of the wood species. If you are trying to duplicate the look of a factory finished floor where they boast multiple coats of finish, don’t. The process is much different and all done by machine.

One more coat should make a difference if you follow what I said above. I wouldn’t use rougher than 120 grit to rub the edges. If you have access to a polisher, I would try 180 grit screens and work down if you need to. Be careful not to cut through and remove the stain.

Moisture cure still off-gassing

Q: Hello, I have had Toby Lustapol oil polyurethane put on a timber floor. It is coming up to 3 weeks and is still off-gassing. We also notice when moving furniture there are marks left where it sat? Could you advise what these marks might be? The marks look as if you left a drink on a wooden table.

It has been below 20degress Celsius and around 10-15 at night here since the floor was coated. The floor was newly installed with barrier seal applied and 2 top coats.

A: I’d never heard of the product but looked it up. It is moisture cure. It should be tough when cured, but nasty to work with. The finish dries by exposure to moisture. If the air is too dry it will greatly retard drying and curing. You may need to set up a humidifier. Have you contacted the manufacturer or the people who sold you this product?

One area of floor remains dry after multiple coats of finish

Q: I poly’d my floor with 3 coats, but in one section it was dry. I went over it again and it’s still dry. What should I do?

A: Did you buff or sand after each coat of finish? After applying the first coat on bare wood it would be spotty and maybe a little rough. Sanding it lightly with a fine abrasive would smooth it and help close the surface. With each coat you should see marked improvement with the finish build. 3 coats is generally plenty. Was this applied to a floor which has been sanded to fresh wood, removing all previous coatings? If so, perhaps that area that appears dry may not have been sanded smoothly? If this finish is applied over already existing coatings it may be there was contaminants on the surface which are actually repelling the finish. If this is the case you would have to wet buff with a polisher, maroon or white pad while spraying a cleaner such as Poloplaz Tie Tac to remove contaminants. Worst case the floor has to be done over again from scratch.

Polyurethane wrinkling due to environmental issues?

Q: We had our floors refinished, and the second coat of polyurethane bubbled and cracked everywhere we had oak (there was pine in the kitchen). The first coat went on fine, but the second coat looked awful. The contractor said it was our fault because the baseboards were off so it was too humid (they were off before they started). We fixed the baseboards, put foam in the cracks to the exterior, turned on the heat for a few days, and they are still having trouble. The guy said he would sand it and re-do it one more time and then abandon the project because it’s an environmental problem not his problem. Is there nothing else we or he can do to make this work?

A: What do you mean by cracking? Do you mean it has raised edges that look a bit like alligator skin? If so, this is called wrinkling. It is caused when a coat of finish is applied over a previous coat which is not sufficiently dry. The solution would be to make sure it is warm enough for a typical finish to dry over night. That would be 70 degrees at least. High humidity can also slow drying. It’s winter. I wouldn’t think that would be an issue. The floor would have to be well dry and then aggressively screened with a polisher and abrasive screen pad. That is assuming I am understanding what you describe. I find it hard to believe not having the baseboards in place is responsible for this. The first coat went on fine as you say. So, it sounds like there was a reaction between the first and second coat as I mentioned above.

Follow-up Q: Wrinkling sounds right. When the first coat went on Wednesday two weeks ago it was like 60-70 degrees with low humidity (Houston, TX) and then when the second coat went on Friday the temp dropped and there was a lot of rain/humidity. They scoured off some of the wrinkled coat of polyurethane yesterday and then put another test coat on yesterday after we had the heat on and it started wrinkling almost immediately.

He said he’s going to give it a few more days with the heat on and do another test of polyurethane and if that doesn’t work he’ll go with a wax finish instead (as opposed to abandoning the project now..). I think you’re probably right about the first and second coat reacting, but it sounds like this is the first time this has happened to that guy in 10 years and he doesn’t really know how to handle it. I’m a little nervous about the wax finish, but we really just need to get into the house and I’m sure it’ll look nice.

Thanks for your feedback! I was finding it hard to believe as well that there were “environmental” conditions that he couldn’t work around.

A: If it is going to wrinkle it will happen immediately. Is there a basement under this floor or a crawl space? I’ve heard Texas is really getting punished. Flooding, and then major snow storm? If you have cold air coming from under the floor it can take several weeks to dry unless you have a heated floor or a heat source under the floor. He may need heat and a bit of ventilation also because this means there likely is still a small amount of solvent left in the coating. While not always the case, generally if the finish is dry enough to recoat it will powder when the first coat is buffed. If it isn’t dry enough the finish will roll off as tiny clumps.

Missed a couple spots coating with poly

Q: Our wood floors have had new poly top coat. There are a couple of places that appear were missed (part of one board). How do I correct this? Since it is still bare and recently sanded and cleaned is it as simple as brushing over the missed area with poly?

A: I think I would lightly but thoroughly sand with a fine abrasive the entire board affected. Clean off all the dust and then apply painters tape on all 4 joints, 2 end joints, 2 side joints. Apply a thin coat of finish and remove the tape immediately.

Repairing factory finished floor defects

Q: I live in an apartment with prefinished hardwood floors recently installed throughout. The floors are solid maple with a factory applied satin finish. On two of the boards in one room, but nowhere near each other, I have some pretty bad flaking off. It’s of the entire finish, all of the way down to bare wood in a couple of small strips, going with the grain. I know for a fact that no damage has been done to these boards and one of them has always been covered with an area rug. It is pretty obvious to me that this is a factory defect in preparation and most likely this was one bad boards that has been cut and placed in the same room as one of the damaged pieces is quite short. I would like to repair the damage myself prior to moving out because my landlord is crazy and I know he will blame me for this. The chipped areas are small enough that they could be filled but I am having a hard time finding a way too match the texture of the sprayed on satin finish. I am also not sure what type of finish would be best for filling in these chips. Thank you for your advice!

A: Nothing you could do would match the existing look from the factory. So, without some spare boards from the box so you could remove the damaged boards I don’t know what to suggest. It sounds to me you are correct that it is a defect from the factory.

Flaking polyurethane finish

Q: We recently refinished the 1700 sq ft of red oak wood floors in our home. It had been a prefinished floor when initially installed, so it was a bear to sand down, but we got it done. We sanded them well, vacuumed and wiped them before applying stain. We stained with oil based stain then put on 4 coats of oil based varathane polyurethane. Now, just weeks later the floors are flaking in small areas and in between boards. How can we fix this? Thanks!

A: Question: given that this was factory finished, did you sand it down until the bevels disappeared? Or, if they were large bevels, did you hand scrape the existing finish off each one? If not, that could account for the flaking finish. Adhesion issues generally fall into two categories: contamination issues and insufficient inter-coat abrasion. In other words, if the previous finish application is not thoroughly abraded with a fine abrasive you may fail to gain good adhesion. You are likely going to have to start the entire process over because you likely can’t know at what stage the adhesion issue begins: between the 2nd and third coats? Maybe between every coat? If you attempted to screen most of the finish off it would be near impossible not to disturb the stain. 4 coats sounds like a bit of over kill also. By piling on too many coats at once, you impede the time for the previous coats to cure. If I used a stain containing urethane resin such as Dura Seal quick coat, I would stain and apply 2 coats of poly. Other stains I would apply 3 coats.

Follow-up Q: Yes, we sanded down beyond the bevelled edge, so the floor was completely even. We sanded with 20 grit, 40, 60, 80, then 100. We followed the directions on the varathane can, which stated we needed 3 coats at minimum, but more was preferred. The thought of starting over makes me sick, but if that’s what needs to be done, so be it. Is there a better finish we should be using? We have many scratches already (though we knew some would be inevitable, as we have a large Labrador). Thoughts on tongue oil? Thank you for your advice.

A: For a polyurethane finish I’ve never used one better than Poloplaz Primero. It’s tough and easy to work with. Waterlox is a nice tung oil finish, though somewhat expensive. While not offering the hardness of a polyurethane it is very easy to refresh it.

Floors still tacky after 12 days, finish not drying

Q: We just had our floors sanded and refinished and they still feel tacky after 12 days. The finish was oil based polyurethane (DuraSeal). Our house is in Hawaii at the top of a mountain where the rainfall is very high, but I do not know our relative humidity percentage. Our flooring contractor is telling us to open the doors every day for the next week to let it air out more, then move in and see how it feels in a month or two. I had another very respected flooring contractor come and look at it and he said oil-based polyurethane was the wrong finish for where we live and that it might not ever dry. He recommended a re-sanding and using a water based (or combination) finish. In addition to the tackiness, there are lap marks from the squeegee and blistering (looks like air bubbles and feels rough like sand paper) in some areas. We have been out of our house for three weeks now and are extremely frustrated. Hoping the stickiness will go away, but refuse to move back in with it sticky. We can afford to stay our another week, but fear it might be futile to wait any longer. So my questions are 1) if it still tacky after 12 days, is it likely for it to ever dry? and 2) Is there anything short of re-sanding and finishing that we can do to solve the problem?

A: Okay, so it has been 12 days and it is still sticky. And it’s rough. So the really bad news is no matter what, it will have to all be buffed down and coated again to fix those issues. Is a solvent based finish the wrong choice for the environment? Not necessarily. Not all finishes are created equal and some dry much better under difficult circumstances than others. Water borne coatings can have issues of it’s own in high humid conditions.

I have seen solvent based coatings as wet the next day as when first applied in cool, rainy conditions where the house had trees draped all over it. This means high humidity. However, opening the windows solved that issue. The coating was dried the following day. The only time I’ve seen tacky floors after more than a week is when a very old floor which has been waxed for years is finished with a solvent based coating. There is wax between the boards which won’t come out and the solvents in the finish soften it and reacts with the finish. Even then it will eventually dry. Other than getting fresh air and warmth into the rooms there isn’t much more to be done but wait. Or have the other guy sand it over. Not a fun job to remove soft finish. You can use water borne coatings over solvent coatings. However, it must be totally dry and solvent free or it will peel off. So, your choice is: wait it out and then have it buffed and coated with water borne or have the guy come in and sand it all off. It’s unfortunate and I can understand your frustration.

Follow-up Q: Thank you very much for the quick reply. I really appreciate it! The windows have all been open for the past week and a half and I’ve left the doors open too for a few hours on each of the past two days. Still tacky, but I am sceptical, holding out hope. If we decide to wait it out longer, is it safe to move back into the house with tacky floors? Or will we damage the floors by moving furniture back onto them and/or walking around barefoot on them? Is there a certain number of days/weeks/months after which waiting longer would be futile? If they are still tacky after a month or two, is there a chance the tackiness is here to stay?

A: You know, I’ve been at this over 40 years and I have seen floors stay sticky, usually along board edges and in severe cases in heavy grain for a week or more. Not a month or more. and it was always with very old, wax treated floors. Do your floors fit into any of this?

I think the idea of damaging the floors, or more specifically the finish is a mute point because you already said it was rough in spots and not even fully cured. Not even fully dry. So, I don’t think you can hurt anything. The floor at some point would need to be screened down and coated again anyway. But this can’t happen until it is dry. You can’t even coat the floor again with solvent or water borne coating until that happens. Poloplaz has a good cleaner called tycoat. I’d like to see what happens when the floor is scrubbed down with that thoroughly. I don’t believe this is just an environmental issue. It is a contamination issue.

Perimeter of hardwood floors peeling

Q: I refinished my hardwood floors a couple of months ago. In a few areas, mostly close to the walls, there is some peeling and flaking which suggests to me that I failed to sufficiently sand those areas. Even though the areas are small, a noticeable ridge is left where the poly flaked away. Is there any way to smooth out the ridge without damaging the finish?

A: You could try buffing the affected boards thoroughly with fine sand paper and applying a thin coat. If you have a noticeable ridge it causes me to wonder how heavy a coat of finish did you apply? Many finishes have a spread rate of 500 sq. feet per gallon. Thin, even coats are always much better than heavy. If this peeling continues you may have to have the floors taken down to clean wood again which means starting over.