Poly repelled from seams of sanded wood floor

Q: I just sanded some old floors that I installed about 20 years ago. I sanded them with 40 grit, 60 grit, 80 grit, then buffed it with 100 grit screen. Then I put golden oak stain from Minwax. After the second coat of Lenmar oil poly, I went to put third coat on and I noticed all through the house at the seams and the butt joints the poly looks dry and the middle of the board is shiny. It looks like I missed polying the seams. What could have caused this? I have picture if you would like me to text them to you.

A: Sounds like a contaminant. Were these floors waxed by chance? Because it can get into gaps between the boards and the solvent in the polyurethane causes it to bleed out and repel the polyurethane.

Q: We moved into a 50 year old house. Before moving our furniture in, I sanded the floors, applied several coats of Minwax oil-based stain, and applied three coats of Minwax polyurethane, also oil-based. Five months later, the polyurethane appears to be separating from the wood at the cracks between the planks in high-traffic areas and in some places the separation creeps toward the middle of the planks. The floor boards do move somewhat, but aren’t particularly unstable.

Is it common for the movement of boards when being walk on to cause this separation of the finish? Should the finish bond strongly enough to the wood to tolerate this? Maybe some contaminate is to blame? Is there any way to fix the problem spots so the bare wood isn’t exposed?

A: If the finish is peeling in the center of the board, you probably didn’t buff/scratch the previous coating enough to gain a good bond.

To fix it you will have to buff the finish down to the finish film that isn’t peeling. This will be tricky to do without removing the stain too. If it is just a couple of boards, maybe you can tape them off and just do those boards over.

Follow-up Q: The peeling doesn’t begin at the center of the board, it begins between boards where there is slight movement when the boards shrink in the winter. Only on some of the boards it spread from the cracks into the center of the board. Are you saying it’s common to see this issue at the cracks but if it spreads to the center it’s indicative of poor bonding? How can I tell if it’s just a layer of the poly peeling up or if its actually exposing bare wood?

Sorry for the persisting questions.

A: I wouldn’t say it is common to crack and peel at the edges. This could happen if there is serious shrinkage. The finish will only stretch so much and then it will fracture. But it won’t peel off the board unless there is a bonding issue.

Too thick coat of finish not drying

Q: Recently I restained our wood floors. Sanded, restained, then put poly on them. When we walk it leaves foot prints and there are some cloudy areas. What can I do to get rid of them

A: I’m not at all sure what is going on here. It sounds like a surface contamination. Was anything else wiped or applied after this work was completed? Perhaps something used on other wood work or furniture where a spray mist perhaps drifted down onto the floor? If that is the case you will need to use a cleaner to remove the contamination. Poloplaz has both a floor cleaner for general use and another for more serious issues called Tie Tac. If this is not the case and you have had no adhesion issues between coats, I would lightly but thoroughly sand down the final coat of finish, thoroughly clean up the fine dust and apply a thin coat with a roller using an excellent finish such as Poloplaz Primero satin finish.

Follow-up Q: When I put the final coat on I put it on thick and it seems soft as if it hasn’t cured yet. Will it harden eventually? Also it was a gloss not satin.

A: It will harden over time but I don’t believe it will ever be as tough as if you applied it at the recommended spread rate which is usually 500 sq. feet per gallon. I’d leave it for now and not even think of doing anything with it for at least a month. At some point later you may get a floor polisher and use 150 or 180 grit screens and buff it down really well before applying a thin coat. The edges will have to be sanded by hand. I use 120 grit for that on my hands and knees.

Follow-up: Thank you for the information. It has been a month but the weather has been all over the map. Hot cold rain etc. I will give it more time and then do as you suggested. Thank you again for taking time to answer.

Related Q: We put way too thick a coat of poly down on our refinished wood floor. It has been a week with the fan on it and it’s still not dry all the way through. The very top has set up but any weight and you sink down into the “un-set” part. Any trick to get this to totally dry?

A: Many finishes have a spread rate of 500 sq. feet per gallon. If you apply it at half that, 250 sq. feet per gallon, I could imagine it will take at least three weeks for this to harden enough to proceed. Lots of fresh air, warmth and time are all you have unless you want to sand it all off and start over. 3 Thin coats are always far superior than one thick one.

Polyurethane went bad?

Q: I had my floor professionally sanded, and then I stained it myself, and put a coat of water based poly on. Now the floor looks very dull and chalky. I waited 48 hours for the stain to dry before applying the 2 coats of poly. I did the same thing in another room 6 months ago, and that floor looks fine. I used the same container of poly. Is it possible the poly went bad in those 6 months?

A: I’m not sure. Is it possible when you first used the finish it wasn’t stirred up that much? I ask, because it sounds like now you have a lot of flattener in the finish making it appear matte.

All finishes have a shelf life of about a year. But it is my understanding that out of date generally affects the agents that control anti foaming and flow and not necessarily the integrity of the coating itself. You could try re-coating with Poloplaz 202, a 2 part water borne which has the cross linker built right into the finish so there is no product waste due to short pot life.

Follow-up: Thanks, I think you hit the nail on the head! I just finished applying a 3rd coat of poly out of a new container, and it already looks a million times better.

Chemical eating poly away; top coat of poly bubbling in two areas

Q: If a chemical eats through the top coat of poly would it also eat through the other 2 coats?

My hardwood contractor did a screen and added 1 coat of oil based poly to some hardwoods that were new in 2006.

There are two areas that have little bubbles popping up and you can scratch off to the next layer of poly. He believes this was something that was spilled or sprayed on after the re-poly and is eating poly away. Wouldn’t the chemical eat through all layers? Could this be caused by bubbles in poly or having heat on after refinishing?

A: I don’t believe this is caused by a chemical stripper. It could eat through more than one layer at a time, but regardless it does dry out and stop activating after a while. There could be some other contaminant on the floor, however, which is preventing proper adhesion on certain spots. Having warm air blowing directly on the finish when it has been first applied is not a good idea either and can cause bubbling because of the rapid set up and evaporation of the solvent.

Finishing hand scrapped floor

Q: I oil rubbed a hand scraped oak floor. The rough grain is dull, while the closed (smoother) areas are shiny. I need to make it look uniform. Less shine. Any thoughts? I am a flooring contractor, so I do have the equipment.

A: Well, of course the open grain, much softer than the surrounding wood will absorb more of any finish so you will require more coats. I would suggest going with a product such as Waterlox. You just mop it on with no need to wipe it off or buff it. It co adheres and builds.

Brazilian walnut finish is tacky

Q: I recently finished a remodel job on a one level home in Northeast Tennessee. The species of the wood is Brazilian Walnut. The troubles and learning experiences outweigh the cost of labor. The home had 1100 sq ft of pre-finished Brazilian Walnut in it already and I installed 300 sq ft of the unfinished. The pre-finished floors were 5/8 x 2 3/4 and the new unfinished wood I installed was over a sunken living room which I raised up to be level with the rest and made a picture frame design because I was unable to find the same floor. So the wood I installed is the 3/4 x 3 1/4 boards. Extremely heavy bundles! Sanding the pre-finished floors were impossible to do with the standard Norton Abrasive papers which were 36 grit. We special ordered the Norton Blaze and the Norton Red Heat and spent $480 on the paper alone and also added 35lb plate from weight bench set and tied it down on the Hummel. We eventually were successful in sanding the floor.

We put a sealer coat on, then applied a coat of Synteco 35 classic, matte finish. The next day I covered the floor to protect as I was finishing some crown, baseboard, and shoe base before the final coat. So a week later I finish the work, pull the paper up, buff the floor like I have always done for the past 15 years and applied the final coat of this tremendous product we use for the final coat. It is oil based and takes usually 8 hours to dry. I used to use Synteco for all coats even final coat but the fumes were starting to affect me and my cousin turned me on to this process of using just one coat of Synteco and using the Niles Black Bucket Super 95.

This process has yielded so many gorgeous floors and very happy customers. My problem now is, it’s now been 5 days since final coat applied and still tacky. I have learned the hard way about Brazilian Walnut. It’s definitely the toughest, heaviest and oiliest floor I have ever done. I’m wondering if I buff this floor eventually when it dries because it didn’t dry correctly and my roll marks are visible where I sectioned it off, which is the reason I love the final coat product, because how nice it evens out. Can I apply a water based finish if I get the oil based finish to come to a dust? The crazy thing is that the newly installed wood is flawless, it’s the pre-finished wood that’s still tacky. I have been looking for answers and solutions desperately, can you please help me?

A: I’ve not worked with Brazilian walnut (thankfully) but have worked with Jatoba. It was really heavy too. All these woods are oily. Poloplaz has one finish they recommend as a seal coat over these floors to block the oils. Prism is my memory is correct. Well, you are beyond that step now. It’s my experience that you can apply water borne over solvent or oil based. But you have to be sure all the solvents are out of the coating. I’ve had a few times where the finish appeared fully dry and ready for another coat. There was no tackiness. No heavy smell of solvent in the air. The finish powdered when screened. And when I applied the next coat, it wrinkled. Only a few times, but given the slowness in your case I’d give it extra time. Put some heaters or fans in the room if need be.

Prefinished floors are miserable to deal with because the coatings are abrasion resistant. The recommendation is to skim the coating with a 60 or 80 grit to break the surface. Then go to a rougher grit to flatten the floor and remove the rest of the coating.

Synteko! Oh man, I haven’t used those Swedish finishes in years. Very tough but the fumes are unbelievable. You could contact Poloplaz for information on a coating they recommend. Perhaps ask for Bill Jauernig. I use their Primero. The stuff is so consistent. I bet the floor with the boarder looked really good. I’ve only done a couple.

Finish feels like sand paper

Q: I just had my floors re-finished, and new one’s installed. The floors felt as if they had a fine layer of dust all over. And there were lots of sanding marks. The installer returned and tried again. The floors are definitely better, and brighter, but still feel like there is a fine layer of dust (like sand paper). There are still visible sander marks everywhere and it is not a glossy finish. What do I do? The are 3/4 Red Oak with a Swedish finish.

A: If you can’t live with the excessive scratches, the floor will have to be sanded and finished over. Swedish finishes are tough, but extremely nasty to apply, and also nasty to remove. The best chance of hiding any flaws is with a low sheen finish.

Similar Q: We’re moving into an apartment soon. We just got the keys and went by the place. They were supposed to redo the floors. When we opened the door, the floors looked wet. I reached down to check it. It feels like sand. Are there additional steps they still have to do to finish it? Or am I stuck with gritty floor?

A: Sounds like they used Hi Gloss and a lot of grain raise. The floor will need to be thoroughly buffed or polished with a fine screen to knock down this roughness. After thorough cleaning of the floor, another coat will have to be applied. They need to make sure their finishes are clean also. I now work out of gallon cans and after every job I pour the left over finish from a plastic bucket through a strainer and back into it’s original container.

Polyurethane peeling in some of the joints

Q: We had our hardwood floor sanded, stained and polyurethaned in May and now in March (less than a year) they are peeling in some of the joints, and the joints are now white in color. what would cause this and how is it fixed?

A: There are so many possible causes for this, without knowing what finishes they used, how they applied them, and a host of other elements I can only wager a guess. It sounds like during the heating season your floor, because of low humidity has shrunk a bit, and the finish cracked on the joints. The peeling is at the joints, not over the entire floor.

The fix is to have the floor buffed really well, paying close attention to board edges and apply another coat. Any gaps should be filled first. Try to keep a relatively stable relative humidity in the house.

Similar Q: I just had my 14 year old wood floors sanded and stained, and 3 or 4 coats of polyurethane applied. There is now peeling at the seams where the boards come together. The floor guy says it is because the floor gives when you step on it. Could that cause the peeling?

A: If there is significant flex the finish will stretch and then break and perhaps chip, but not peel. In my opinion a more likely reason for peeling on board edges would be contaminants such as wax bleeding up from between the boards, or if there is a lot of movement from one board to the next, the mans polisher probably went over top but missed abrading those edges and he hasn’t gained adhesion.

(After further correspondence…) 3rd A: The problem I am having with their explanation is that you can pull the finish off in the middle of the board with a piece of scotch tape. This is totally unrelated to the movement of the boards and would seem to indicate lack of adhesion in general across the floor. I have seen tape pull of the top layer of water borne, but I’ve never seen it happen to oil modified. However, when it happened it was because the workers taped the floor around the perimeter of the rooms soon after the coating was applied (not cured) and it was in place for days before they started trying to remove it. It wasn’t a case of applying a piece of tape and then pulling it off right away with the floor finish stuck to the tape.

I can’t question the ability or integrity of the company who did the work. After 35 years I know sanding, staining and finishing is so hard and technically difficult, sooner or later a job will go south. I would think that if they care about you, their customer, care about the type of work they do, and want to have a good reputation, they should try and make this right even if it means starting over. That really seems like the only option to fix this. Putting another coat of finish over top of one that is not adhering is not going to fix the problem.

You would probably be well served if you could find someone local to provide you a second opinion with a home visit.

Similar Q: What can be done about white lines in between boards of Walnut wood flooring?

A: Difficult to say. What caused the white lines? If the boards shrank and stretched/cracked off the finish you will need to control the environment and humidity or lack of it. A buff and re-coat may get rid of the lines.

Will applying additional coats correct fish eye bubbles?

Q: We attempted to apply a top coat of polyurethane on our old floor with a roller. It is full of bubbles. Will applying additional coats correct this?

A: You will have to rub this coat down really well to knock off the bubbles, especially so if they are fish eye type. Some finishes roll on very well but you must make sure there is no air movement across the floor for several hours after applying the finish so that it doesn’t set up too quickly and allows the finish to flow out smoothly.

Similar Q: Why does our floor have bubbles between most of the floor boards, after it was recently refinished?

A: Is this just bubbles or actually beads of finish on board edges?

Bubbles can appear if the solvent is evaporating too quickly. This can happen, for example, if there is a sky light or a lot of window exposure with direct sun light heating the floor. Best to cover the windows while coating.

Polyurethane coating is flaking

Q: We have a guest house with pine floors. I have sanded them, applied and oil base stain, then went over them with a polyurethane. I applied about 4 coats of poly in 7 days time. The floors looked great for about a month (they weren’t even walked on) and we had a cold snap in weather. I noticed my floors had almost a frost look to them and they were flaking like crazy. Can I just buff the floors with a screen and redo the poly in a day instead of a week? I am learning that I should not of let them dry that long between coats. The floor scratches like crazy.

A: If the coating is flaking seriously you will have to start over. It’s likely you have flaking between all the coats between the first and second all the way up to the fourth. What you have here is lack of adhesion. Adhesion is attained between coats by applying a coat of polyurethane, allowing it to dry and then thoroughly buffing or abrading the coating with a fine abrasive. Essentially you are applying a fine scratch to the finish to allow the next coat to grab. This has to be done between each coat. You will know if a coat of finish is dry enough to proceed if it turns to a fine powder as you buff it and you aren’t having the finish roll of in little strings or clogging the abrasive. 3 coats of finish initially on a stained floor is plenty to start with.

Follow-up Q: Can I do this with just a screen buffer? I am thinking that a sander is to much. I don’t want to pull off the stain.

A: You can certainly attempt it as a last ditch effort before going the extreme but necessary route of total resand. The difficulty is you don’t know for sure on where the peeling starts. Is it failing from the second coat up? You will likely have to screen it fairly heavily, removing a lot of the finish and so there is a very real risk of cutting into the stain with the screen.

Related Q: We have white lines where the polyurethane looks like it is flaking off. The floor was stained with Miniwax and an oil based polyurethane. The main areas of stain were applied at least five days before any polyurethane was applied. The polyurethane was applied in three consecutive days. We have been using a cleaner that contains ammonia and washing the floors every two weeks. Could this have caused the white lines? If not what could be the cause?

A: It sounds clearly to me you don’t have adhesion between coats. This is achieved by thoroughly buffing each coat, that is scratching and deglossing prior to applying another coat. It is really a mystery to me why you waited so long to start applying the finish coats on the stain and why you would be using such a strong cleaning solution in the meantime. Preparation is everything. Clean environment. Good temperatures. It seems clear to me this has not been professionally done.

Finish bubbling in darker spots of exotic wood floor

Q: We had a pre-engineered Brazilian Mahogany floor installed circa 2004. We started to notice dull spots and tiny bubbles in finish over time, but only evident where wood has darker colors. I brought it to attention of manufacturer, and they admitted it was product defect. (They provided cash settlement!) I experimented with one board that was badly bubbled.. sanded out bubbles, recoated with poly. In 6 months, finish is again loaded with tiny bubbles. If I have floor sanded and refinished I fear the problem will recur. 95% Of floor is unaffected.

I wonder if I should have the worst boards replaced with lighter color boards and be done with it, or do that plus refinish?

A: I sounds like an abundance of oils in the wood causing this issue. There are water borne sealers and finishes which are advanced as excellent blockers for oils in exotic woods. www.poloplaz.com has at least one such product they recommend. If course, it you have some boards left over it would be less expensive and far less disruptive to simply remove the offending boards and pop in replacements.

After three months finish started to blister

Q: A floor contractor sanded our oak floors to the bare wood and finished them, leaving a lot of small grit and hairs under the finish, so he redid the floor, and it looked even worse after. On the third try his job satisfied us. He used an oil coat of some type and a water based poly for the final coat. I am not sure what his exact process was.

However, after three months the finish started to blister, mostly starting in the cracks between the planks. This is happening throughout a very large area in several places. What would be the correct way to fix this problem? Our General Contractor wants to have it buffed and one coat applied. Does this make sense?

A: I suspect the first coat he applied went between the boards and didn’t dry. Is this blistering or tiny beads of polyurethane? If the latter, this condition is known as poly beads or poly balls. You may have to keep scraping it off until it finally dries and stops.

If it is actual blistering, you likely have a reaction between the incompatible solvent in the initial coat (mineral spirits) and the water borne poly. In that case you may have to sand yet again. A clean environment and clean finishes are imperative to provide a good looking floor.

Fisheye and many rough spots after finishing

Q: We had our 48 yr. old oak floors refinished by a pro, sanded to bare wood and 3 coats of oil base satin poly. I complained that there were many very rough edges and swirl marks from the buffer, so the pro then buffed and did another coat of poly. This time with a different brand, Fabulon, oil also. (Not sure what brand the previous three coats were.)

While applying the 4th coat he started seeing what he called fisheye, spots where the finish didn’t adhere well. He buffed and did a 5th coat, not as bad, but still some fisheye and many rough spots. I don’t think he tacked with mineral spirits after buffing, would that help prevent fisheye? Should he use a finer screen to prevent swirls and rough spots? Thanks.

A: Everything we do when sanding and coating floors involves scratching the wood and the finishes to gain adhesion. The aim is to make such scratches fine enough that they are not visible from a standing position. I’m surprised you could see swirls through the satin. I wouldn’t use a screen any rougher than 180 grit when buffing between coats, and prefer to use even finer 220 when possible but that depends on how hard the previous coat is when I buff it. There are also newer abrasive pads created because of the swirl issue. 3M makes a maroon pad which can be used with 180 grit sanding strips and now Norton Abrasives has created a line of abrasive pads which promise not to leave such marks.

I always vacuum then wipe the floor down with a micro weave mop before coating. Wet or dry doesn’t matter. All air movement should be prevented after application so the finish will have time to smooth out before setting up.

Similar Q: Is there any other way to get rid of the tiny air bubbles in my floor besides another coat of poly? Can I sand them with 220 grit screen and then apply a wax to bring back the finish?

A: You will need to abrade the surface coating to knock down the bubbles and apply another finish coat. Make sure no air is moving across the floor while it sets up. I definitely would not recommend applying wax over this top coat. It will be very slippery and impossible to keep clean.

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.