Floor Finishing Help Request

[Colleen Devine]

Hi,

I am requesting some help on the behalf of a friend, so I have some of the basic information, but perhaps not all the pertinent details at this point.

Her husband installed a Flooring Destinations laminate flooring. The top layer is oak, but I'm not certain how thick or "sandable". It came factory-topcoated.

They sought a glossier look and increased high-traffic-area protection. To that end, the following occurred:

Day 1: Zinsser shellac was applied.
Day 2: Minwax polyurethane floor finish was applied.
Day 3: A cloudy, scaly appearance (possibly "fisheye") developed.

He sanded, using a palm sander, down to mostly bare wood; a few glossy spots remained, and I believe she intended to advise him to remove those.

Your help with "What happened?" and "How shall they proceed?" will be greatly appreciated!

Regards,
Colleen

[Steve Schoene]

In that context only one of Zinnsser's shellac products would have been appropriate. Unless they used the Seal Coat dewaxed shellac, polyurethane varnish will not adhere properly. Polyurethane is very picky in that regard. It also requires sanding between coats unless applied within a very precisely defined time window. Use no finer than 320 grit for a good bond.

As far as increased high traffic area protection, the original factory finish was likely to have been much more durable than the Minwax single part consumer grade poly.

At this point, I would concur that any significant shiny spots need to be removed. Unless the floor is uniformly sanded it will be hard to get a good finish. If any wax or cleaning products had ever been applied to the floor, it should also be washed off with plenty of solvent, applied with a great many rags or paper towels so that the material will not be smeared around but will be removed. Sanding will not remove such contaminants.

Then I would use a high quality floor finish. The Bona Kemi line gets very good reviews. Manufacturers directions should be read carefully, and followed in all details.

Perhaps the best lesson for all of us to take away is to get the "customer" to sign off on the finish before it is done.

[Sam Shank]

I would blame the zinser too. It's easier to do your homework before the snafu. ;)

I also second bonakemi finishes. Very easy. I have been turned onto varathane's water based finish recently too. I like the way it goes down and the way it powders up when you screen the raised grain you get with any water based finish. I pick this stuff up at Lowes when I don't have time to go to the hardwood floor contracters place around here.

It's hard to beat the ease of application with bona though. And you gotta love the no buffing between coats required.

[Howard Acheson]

While it's too late now, the first thing to have done would have been to contact the flooring manufacturer. As Steve said, the finishes applied to pre-finished floor are far more scratch resistant and durable than anything that a DIY'er can apply. They are very difficult to get another finish to adhere properly even if they are properly scuff sanded. Most manufacturers do not recommend that any store bought finish be applied.

At this point, all the existing finish must be removed and any contamination needs treatment. Most of these floor systems have a fairly thin veneer of wood so sanding must be done carefully.