I thought about this a lot too when I was trying to make the decision. I ordered a sample of pre finished oak and tested it. Aluminum oxide may be tough, but it does scratch pretty easily. And the worst part of it is that once it does scratch, it is very difficult to repair. It is a baked-on finish and cannot be done on site. I don't like the micro groves of prefinished floors either. I think since you already have some site-finished oak there, the contrast would be pretty great between the two, one having a smooth surface and one having micro-groves. I have 3 house dogs. two don't count, since they weigh less than 10 pounds combined, but the 3rd is a very active pit bull. I know she will scratch the floors. So I have decided to go with Waterlox finish. It is easy to DIY, and it is VERY easy to spot-repair. You can't really say that between waterlox, aluminum oxide or poly that one is better than the other, they are all just different. The same smooth finish can be achieved with any of the 3 of them. As far as why some installers don't like prefinished? They have to be too concerned with scratching and damaging it during installation.

Interesting....

Is it more difficult to repair prefinished vs. polyurethane site finished flooring? With site finished, I always thought you had to resand and recoat the whole floor and that it wasn't possible to spot repair? Wouldn't that be the same w/prefinished?

I have heard of Waterlox but are you saying that you CAN spot repair with waterlox but not the site and/or prefinished?

I imagine that waterlox, aluminum oxide and poly will all scratch and wear. I still think the aluminum oxide will wear better over time than the site finished (I have seen side by side evidence of this) but now you've got me thinking about waterlox.

Which would have a longer curing time - waterlox or site applied poly (assuming 3 coats)?

It is possible to repair a site finished hardwood floor when a commercial quality waterborne two-part polyurethane is the finish of choice.

And, these finishes are completely cured usually in seven days...minimal odor...low toxicity...nonflammable and durable.

A waterlox repair is as simple as hand-sanding the area to be repaired and painting on a little waterlox. There's lots of threads on here about waterlox.....you can spend hours reading them. I have yet to read anything bad about it. Aluminum oxide is a good finish....but I don't think ANY finish will hold up well to big dogs and little kids. I am not a professional floor installer, but I think I read somewhere that to refinish an aluminum oxide floor, a heavy sanding is necessary to remove the old finish before a new finish can be applied. A site applied poly can be refinished much easier. I hope one of the flooring professionals will chime in here, because I just don't know for sure. I do know that for me, waterlox is the perfect solution.

Ok - I am seriously considering Waterlox.

Three more questions and I think I've got it (hopefully):

1. How much down time (time we can't walk/live on the floors) for applying Waterlox vs. site applying 3 coats of poly? This will be for new unfinished red oak plank flooring.

2. There will be existing poly'd floors that I will not be able to refinish at this time. These floors will abut the new floors in 3 places. If I were to finish the new floors now and wait to finish the existing floors later - which product would be more advantageous in terms of work involved -- or will it be the same for both?

3. I understand that Waterlox is much easier to repair than poly. But how much easier is it to scratch and scuff than poly? Will I be constantly retouching/repairing this stuff?

Just trying to carefully weigh my options before making an informed decision.

Thank you all so much for your help!!

bump!

here is a quote from another posting

"use a commercial two-part waterborne polyurethane, such as that made by BonaKemi, Basic Coatings, Vermeister and others. These are available at flooring materials dealers and distributors. They are not cheap, but definitely worth the price."

Two component or moisture cured Urethanes are virtually indestructable. Definately have them professionally applied.

I have a factory finished oak floor. I've been told that i can't spot finish by many, the entire floor ahs to be sanded and refinished. I have been refinishing furniture all my life and spent 15 years in the wood finishing industry. I'm going to give it a try. I feel i can blend it in and finish with 320/400 grit wet sand

a prefinished is more easy to replace a single plank if it gets damaged, so for example you had a water leak you could pull out the 7 or 8 boards and repair vs the need to resand the entire flooring area. If scratching or wear starts appearing you can recoat the prefinished without ever resanding. Flooring is a constant trade off, which makes decisions harder and unfortunately there is a lot of bad information out there.