You needed to sand smooth the finish between coats knocking down the normal nits left from sanding and debris drifting down from the air or pulled out from the edges by the applicator. Oil poly needs to be abraded to adhere coat to coat.

Four coats is too much urethane anyway and may well not allow for normal expansion - contraction of the boards. The problem is "side bonding" or the sticking together of the boards which will give at their weakest point when dried out in the winter. This creates fewer, wider gaps than would otherwise occur.

woodfloorpro, thanks for the response. Sorry, I lost track, trying to deal with this, BUT I did read your response, which helped. We have a different floor guy coming to fix it. He looked at it, and said what you said, that he would do a light sanding/screening, to take down the bumps, and then he would buff it, and then put a coat of poly.

QUESTION: The 4 coats were done with Parks Pro Finisher, oil-based (I think by Rustoleum). I don't know what this guy will be using. I talked to a different hardwood guy who said this coat should be Bona. The 4 coats that are on the floor now look very pretty,with a clear look. (It's semi-gloss). You do have to look close, when light hits it, to see all the bumps. I have been reading in "Contractor talk", online to use Bona as a last coat. Does that matter if Pro Finisher is used, or another kind? He's coming to start tomorrow afternoon.

Another question: is after this is done, is this one addition coat enough, because all the bumps have to be sanded down?

It does have to be an oil based finish unless it has been more than a month since the last coat was applied. After a month a water based finish (which Bona is famous for) may be used.

There are many fine brands of urethane and some not so good. The original Zinsser - Parks was a good choice.

Hi woodfloorpro: He came today, screened everything and then buffed, and vacuumed, and will come tomorrow at 10 a.m., and vacuum again, and then apply the poly ....(It's been only 1 1/2 weeks since the Park's Pro Finisher Oil was put.)

I asked him about using BONA, and he said that he always uses HARCO and likes that. He said he would use Bona, .. I offered to pay the difference (I think it's only $50 more for the 2500 sq.ft.). I would have to let him know 1st thing in the morn.

QUESTION: Is Bona's oil based(called Woodline) as good as their waterbourne. AND do you know if HARCO is good. He said he's never used Bona Oil base (only the waterbourne).

..ANOTHER QUESTION!! I'm worried if he uses Bona Oil and is not familiar with it, could I have problem, instead of Harco that he is accustomed to ....it's just because I've had so many problems, and this is the 5th coat, ...would I be taking a chance if I ask him to use something that he is not familiar with?

HARCO is also a good choice. Let him use what he is comfortable with. I trust he took a good bit of the finish off as mentioned above too much finish is not better.

woodfloorpro, thank you so much for your advice, and support, because this has been really stressing me out. being the last step of a long 1 year total renovation. Yes, he did do 1 heavy screening, I think with 120 grit and then 1 buffing with a higher grit. But afterward, we could still see the bubbles, so he did ANOTHER heavy screening with the low grit. Then, after that... no bubbles, but another layer is off (it had 4) Today, he vacuumed again, and put 1 coat of the Harco, Silk Polurethane in semi-gloss.

But now I'm wondering if after having the 2 heavy screenings and also 1 buffing, if one coat of poly will be enough to be the equivalent of 3 coats? I know too much poly is not good, but could it be too little?

After the additional heavy screening it looked like it lost most of the shine and felt very smooth. Should I be worried about not enough poly? I know that you can't see it, but does it sound like one coat of poly will do it at this point?

If anyone is reading this and knows an answer I would appreciate it. ....We went in today to look at the floors and I can see circular scratches most everywhere. Is there a way to fix that? And the finish of the Harco semi-gloss doesn't look as "clear" as the Park's Pro Finisher looked,(Park's Pro was used up until this coat). I'm so sad. I hate the floors and don't know what to do?

Lenmar oilbase poly - best / The bumps are bubbles from the prev. coats of poly. The poly was applied to thick and didnt dry proper which caused the solvents to release under the new coat of applied finish, which in return caused bubbles. apply with a low nap roller next time after screening and you will never get solvient bubbles.

We used Rejuvenate on our hardwood floors and the wax build up is awful. We are hoping to use a 'buffer' then use a poly water base coating afterwards...Is that a good idea to get the old wax build up off??? They are the original real hardwood floors..Thank you

Rejuvenate is one of those products that quite possible will ruin the floor to the extent that the floor cannot even be refinished ever again. Even thru sanding the floor to attempt to remove the finish.