I have deciding on using 4" american walnut for the flooring in about half of my house. We placed samples of many other woods throughout the house, but always came back to the looks of walnut. Now that I have decided to use an expensive and soft wood, I would like to protect it all I can.

My installer has offered up Poly (cannot remember the brand he recommended...he said he typically uses one if the wood is stained and something else if not...no stain for this floor) and a moisture cure product. There is an additional per-foot charge to go with moisture cure basically due to the noxiousness. He also offered to put an additional coat of poly (for a total of 4) for a minimal charge (good idea?).

This is for a residential home, and we take very good care of our floors (try anyway). No pets and no kids (yet, anyway). I realize no product is going to turn this wood into it's Brazilian namesake, but what would the professionals here recommend? Also, how would moisture cure vs. oil-based poly change the look/color of black walnut? FWIW, we prefer the sheen of satin.

Thanks!

Moisture cure urethane is very tough and can take a beating. It is however very nasty .It smells horrible and is also said to be carcinogenic.One other issue is that it has a low flash point. it isn't as flammable as lacquer but it is significantly more flammable than common oil based polys. It looks similar to oil but I personally think that good oil based polys like Lenmar and Fabulon have a nicer sheen and a truer look.

An alternative is to use a catalyzed water based poly. Two of the best are Basic Coating's "Street Shoe" and Bonakemi's "Traffic" .Of the two, Traffic is the one that is tougher and it has some special properties in that it can be applied in very heavy coats and will lay out smooth like oil does.

Bonakemi also has a hybrid system .You can 1st coat the wood with their dri fast sealer and then top coat with 2 or 3 coats of Traffic in whichever sheen you prefer. The system generally works well as long as the 1st coat of dri fast is allowed to dry thoroughly (24 to 48 hours depending on humidity and temperature)

In my 15 year journey in this trade, I can say that Bona Traffic is about 95% as tough as Moisture Cure urethane. The downside is that the water based polys are very expensive.

Thank you very much for your informative reply. I will speak with my installer to see if he has any experience with traffic. Does it require different application methods than regular (I'm assuming oil-based as he didn't specify) poly?

My parents went with a water based product about 15 years ago and the results there have made me leery of going that direction. Theirs wasn't smooth and looked bad from the very start. I'm sure the products have changed since then.

Thanks again!

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Just did some google image searching on bona traffic on walnut. It looks like the satin bona traffic doesn't have the warmth/depth that oil based poly does. In your experiece, is this the case?
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To answer your questions in no particular order:

Traffic does not have the same kind of depth as oil based poly but it is a close second. And it's important to know that not all water urethanes are the same .Some are quite mediocre in both color and quality. Traffic is a far better product than the much older Bona Pacific finishWhen coated over a oil based sealer like Bonakemi's Dri Fast sealer , you can get a very similar color to oil. In addition, the traffic finish has the best depth and clarity of all the water borne finishes I have used when applied correctly.

Also, many contractors do a mediocre job of applying water based coatings .One mistake is to not seal the floor correctly or worse, to use a mediocre sealer. The two best water based sealers are Hydroline from Basic Coatings and DTS from Bonakemi.Both of these sealers are fairly easy to apply and will buff out nicely where most other water based sealers don't buff out well at all and simply melt and clog the buffer media. Every time I use Bona DTS and top coat with traffic, I get a super smooth floor that is as smooth as oil based poly. Contrastly, a contractor I worked for (13 years ) left all his water based floors quite rough as he wasn't willing to deal with the nature of water based finishes properly and somehow managed to get away with it.

As for techniques , they can vary but in general, when using traffic, you get the best build and leveling when it is applied with Bona's proprietary blue stripe roller which can only be used with a Bona roller handle.It allows for a massive coat of traffic to be applied to the floor and makes the application quite easy . There are other methods as well that can yield good results.

All that being said, I think Walnut looks fantastic when coated with oil based poly. I have some jpegs of a house I did with walnut and oil.I'll try to get them posted.

3 coats of Woodline Satin oil poly on walnut .


vht 160 by paulsecondino, on Flickr

vht 147 by paulsecondino, on Flickr

I will have to agree on the looks of oil poly on walnut...

Do you think a 4th coat is a good idea?

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Talked with my installer. He normally uses Pittsburgh oil-based poly. He was aware of Bona traffic, but I don't think had used it before. He had used Bona Mega...I'm not sure of the difference.

He did say that his supplier had started carrying a german imported water-based sealer that was supposed to be as hard as traffic. It had an oil-based modifier to give it more of the look of oil. He couldn't remember the name. Leaning towards regular old poly at this point...I just like the look
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A 4th coat isn't necessary but is possible.If I did 3 coats of oil in a row, I would prefer to give the floor a couple of days to gas off before the 4th goes on.The reason is that over coating a floor can trap the gases from the under layers and this will cause the floor to remain soft and uncured for maybe a few weeks or possibly a month. This isn't written as gospel but can and does happen.

I have not used Pittsburg poly but can tell you that Lenmar,Fabulon and Bona's Woodline are 3 of the best. Many contractors use Dura-Seal but I don't personally like it.