Faint wave noticed on floor after 3rd coat

Q: Wave showed up on a customer’s floor, no signs until the 3rd coat dried. It is only visible at certain angles and light. What do I do? I don’t know if the homeowner can wait for a refinish. Have a Trio and did a slower pass on the other rooms; staining them soon but will not know if they have waves until the final coat. Once the light is broken up with furniture I doubt they will be visible. The home owner has not noticed them. To mention or not, and discount or redo?

A: Any idea why you had this happen? What about a matte finish? Most people don’t like it and I wish everyone would. The lower the shine the better the hiding. If they haven’t said anything and you are this far along maybe it doesn’t bother them. It’s going to have to be your call. You are so far into it now. If you have to sand it again, you will need to do the ‘rough’ sanding on a bit of an angle to flatten out the hills.

As a side note, if you cannot even see the wave until the 3rd coat, they can’t be severe. We do try to be perfect even though that is not attainable. I know you are honest. You know your customer. I’ve had a couple of jobs when I told the customer whom I’d done a lot of work for in the past that I was not happy with the results this time. They were so pleased with me, they gave me a pass on it being a bit less than my best.

Follow-up Q: Thanks for the response. I don’t know exactly why they showed up this time, and yes they are very faint, nothing like some of the photos I’ve seen online. Just stinks putting all that work in and having a product that is not perfect. Going to start cutting on a 15 degree angle on the first pass from here on out regardless, can’t hurt.

A: Yup, I hear you. I’ve angle sanded the first cut on new floors myself. Just have to make sure to get all the scratches. Since moving to rural central Ontario 4 years ago I don’t see many new floors. I’ve installed 2 pine floors. Of the sanding I’ve done up here, 2 jobs were oak, one was ash and the rest were pine with one hemlock. Now that is frustrating wood to work with.

I don’t consider it possible to do an absolutely perfect flooring job. There are far too many variables. But there are good and really good and there is bad and really nasty bad. We don’t do those type of jobs!

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.

Removing bevels / grooves

Q: We have a ranch style home built in the 1940’s. The living room and dining room are both together. We want to refinish the oak hardwood floors, but the oak is tongue and groove, and there are grooves between each board.

My question is this: what is the best way to make them look as if there are no grooves?

A: If they are smaller grooves or what is called micro bevels they can be sanded off. It is a tough job though.

If they are large bevels from the 1990’s or earlier there isn’t much you can do but scrape and sand the bevels by hand during the process of renovating the floors.

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.

Will putting semi-gloss over the satin really match things up?

Q: I just installed Brazilian cherry floors, which were sealed with Duraseal semi-gloss ployurethane by the floor guy. The painter then sealed the Brazilian cherry handrails and stair treads with Magnalac satin lacquer.

I wanted the stairs to match the floor in terms of sheen. The painter said not to worry because the products are different, he’ll simply put a coat of semi-gloss over the satin, which should match things up. Is that true?

The satin staircase is duller than the floor!

A: It’s true. If another coat is applied to the stairs in the same sheen as the floors it will match.

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.

Products recommended for hardening wood prior to final finish?

Q: I have a house which is nearly 100 years old. The sub floor is 3/4 fir, and the finished floor is 3/4 fir too. However, it has been covered by carpet for over fifty years. It came time to either replace the carpet or refinish the wood.

I’m going for the refinish – and to claim it as a historical representation. However, it is fir, and soft. I would like to use a light stain, most likely oil based, then go over with a hardener or a clear coat that will build up and add significant strength to the wood. At least enough to have couch/table and piano legs stand without damaging the wood. Do you have any products you could recommend for hardening the wood prior to the final finish or would you recommend something like the Swedish finish?

A: I don’t know of any finish that will actually alter the hardness of the wood which is controlled at least in part by how dense or tightly packed the wood cells are.

If you want an initial coat of finish that will penetrate well into the surface, you might consider Waterlox, a penetrating tung oil based product. Easy to work with but smelly and fairly expensive. Then after a coat of 2 of that, you could apply a couple of coats of polyurethane. I use Poloplaz Primero which is an excellent, tough finish. It isn’t as tough as Swedish finish. However, Swedish finish is very toxic and nasty to apply, emitting formaldehyde while curing.

The best thing to do is place some type of floor protector under the piano and heavy furniture legs such as a heavy rubber cup to prevent dents.

Contractor said floors were going to be fragile for 20 days

Q: Thanks for your blog – very helpful. We just had our floors sanded and varnished with a crystal varnish. The guy recommended crystal because he said it was the most resistant finish, especially since we have children. Is this true?

Also, I’m wondering if it’s okay to paint the room (like using ladders and that kind of thing), and when is it okay to put the furniture back on? We’re planning on leaving 48 hours before painting, and 6 days before putting the furniture back, with no area rugs for a month like you suggested. The guy said it was okay to put the furniture as long as we didn’t drag anything on the floors. He said the floors were going to be fragile for 20 days or so.

Do you think this all makes sense?

Thanks so much again, thanks for sharing your knowledge!

A: Crystal varnish? There is a finish made by F****** called Crystal. It is a lower end water borne finish. The floors will be fragile for 20 days? That sounds odd. I hope it isn’t an indication of the quality of the product he has used. Even slower drying/curing oil modified finishes generally indicate normal traffic after 3 days.

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.

I would like to go to Semi-Gloss instead of the Satin

Q: I installed and finished the floors (3/4′ Red oak T&G) in our new home, about 8 months ago. They really came out nice and it was a lot of fun! I used Minwax Satin Polyurethane for the finish and protection (no Stain). Anyway, I think that I would like to go to Semi-Gloss instead of the Satin.

My question is: should I remove ALL the poly with a drum sander? Or can I use a square orbital sander to scratch the surface? Also, If I use a square sander and reveal bare wood in some areas and not others, will these be noticed after I put Semi-Gloss poly down?

A: You really don’t want to cut through the existing finish. That would show. You just need to thoroughly abrade the coating, not missing any spots. The fresh coat of finish will adhere to these scratches and is called a mechanical bond. I generally hand rub the edges with 120 grit and polish with 180 or finer screen.

Related Q: Is there a simple way to dull the high shine on my hardwood floors (without sanding)?

A: If you want to do it right, buff the coating and apply a lower finish with a lower shine.

Refinishing a softwood subfloor okay?

Q: Our house was built in 1900. We have wood floors under the carpet. I would like to refinish them, but there is no subfloor. The cost is what I am worried about. I have been told that I need to put a subfloor on top of the wood and then put down a hardwood floor.

A: It can be possible to sand the softwood subfloor. I’ve done plenty and am in the midst of one at the moment. It depends on the condition of that floor. If it has multiple coats of paint you would likely be facing a lead issue.

Or, you can screw 3/8 plywood over that which provides a nice stable surface to install a new floor over. You can install directly to the softwood if it is in good condition, reasonably flat; however, if it is tongue and groove pine then it is running across the joists, which is the same direction you new floor would run. So, in that scenario you should install plywood to get a really stable floor.

Would you use trow-able filler on Brazilian cherry?

Q: I just installed unfinished 3/4′ x 5′ in. random length boards. I will be doing the finishing.

My question is: would you use trow-able filler on Brazilian cherry, to fill the imperfections/gaps, prior to applying sealer? (I have read that the Brazilian cherry darkens, but the filler does not?)

Have you used filler on unfinished cherry floors? Have you used commercial products or your own mix from the sanding dust?

A: Brazilian cherry is not cherry, but Jatoba. It does darken and can do so rather rapidly with enough light. I think I would try to keep the floor tight on installation and with good climate control, and if the occasional small crack does open, fill it with a caulking type of product such as Color Rite.

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.

Varnish with a mirror like shine?

Q: I’ve sanded and varnished quite a few floors in my current and last house. I always used Cuprinol Original Bourne Seal floor varnish. I love the finish it gives because it is super glossy. I’ve just sanded and stained another floor and tried to find this floor varnish and found out the company stopped making it a year ago. I bought a tin of Ronseal Diamond Hard Floor Varnish in Gloss but it doesn’t even nearly compare to the mirror like shine of the Bourne Seal varnish. Do you know of any other floor varnishes that compare with the Bourne Seal result?

A: I’ve not used Cuprinol finishes. Poloplaz Primero hi-gloss is an outstanding product with a high shine, less slip, very durable and a dream to apply with a roller.

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.