We're seeking opinions / possible solutions to finish concerns on site-finished floors that were completed about three months ago. We're generally pleased with installation and color; however, the finish appears to be bubbling along the board seams in several areas and on a couple of boards. Is this most likely an issue with product adhesion or application? Also, appreciate input about overall durability and protection of the shellac used. If we need to re-do, what are suggestions / considerations (e.g., paste wax, Bona Traffic or other coating)? Meeting with the contractor soon, so thanks in advance!

Details . . .

Users: Two adults and two 30-lb. dogs.
House: New construction in North Carolina.
Hardwood: About 3,000 sf walnut flooring in random lengths; 3-4-5" boards.
Color: No stain.
Finish: Three coats of Zinsser Bulls Eye Shellac (Amber)

Sorry, was this question inappropriate? Not meant to be; just looking for opinions on the best finish coat given what we have now. From what I've gathered, many of you do not favor shellac and we're trying to understand if we should refinish for long-term wear and with what product given what's on there now.

Shellac isn that durable of a finish, most floors sealed with shellac get a wax finish or some other top coat. SHellac will turn yellow fast and doesnt hold up well alone.

I agree with Kevin regarding shellac's properties. As to why there are bubbles in between boards , that is usually due to your coating not sticking well to whatever happens to already be in between the boards. For instance, on a floor that was previously coated with something else , you may sand the floor to bare wood and see nothing.then when you add your new finish , you start to notice bubbles in between boards. It's the new finish not sticking to the old material.Oil soaps and waxes being trapped in between boards can cause this too

There's nothing you can do about it besides buff the floor smooth and try for another coat of something like an oil based urethane. To aid in adhesion, you can try the Basic Coatings Tykote system or the Bonakemi "prep" floor preparation .

With Bona prep, you generally use a 3M maroon pad on a disc buffer and spritz Bona Prep onto the floor and buff it into the finish. It generally helps but may not completely prevent new bobbles from forming between boards.

Thanks for the responses. We've met with our superintendent and the floor supplier, who thinks the finisher used MasterLine satin as the finish coat. That is not certain, however, but we do know for sure that the shellac was used at least on the initial coat. This is a newly installed and finished floor; no previous coatings.

As you may have read in my other post, now we're wondering if we may have the 'white line' problems. Regardless, still looking for suggestions on corrective products and / or processes as we've agreed to meet again soon to discuss course of action.

Thanks again.

White line syndrome and bubbles are different issues. Just google white line syndrome for an explanition and or pictures. It's from the finish fracturing.

Another possibility is you may be talking about poly beads instead of bubbles. Check this video out: http://www.flooringinstaller.com/video/wb-poly-beads

Don't think it's poly beads based on the video. Tried to upload two pictures here; hope it works.

http://www.flickr.com/photos/58910299@N03/5398607850/
http://www.flickr.com/photos/58910299@N03/5398605924/in/photostream/

Definitely due to poor finish and adhesion.

The boards are expanding and contracting which is causing the finish to crack.
Pine moves a lot!
Was the wood properly acclimated?
If so I'd suspect that the finish is on the cheap side. I've seen that happen on jobs that the floor guys used quick drying lacquer type finish.
Could also be poor adhesion. Maybe they used water base stain and didn't let it dry well enough before coating with oil? Or vise versa.

Only one way to fix it and thats to resand.
I would recommend bona natural.
I have not tried it yet but seems like bio poly from earth paints might be a good option.

Good luck. Hope the floor guys resand it for you.

The wood is walnut and was not stained. (Sorry about the photos; perhaps the flash makes it a bit deceiving). We opted for 'natural' with just a poly finish; or so we thought. Again, we know at least the first coat was the Zinsser Shellac because the guys ran short and I went to purchase more on their behalf. However, without talking to the finisher, no one seems certain what the finish coat was but the wood rep said he 'thought' it was MasterLine. The rep and superintendent no doubt will get a hold of the finishing team this week, if they've not already done so. We should be meeting again soon.

It was installed and finished between Oct-Nov here in NC, so weather was mild and the HVAC system was on by the time of finishing if my memory is correct. We understand and expect seasonal movement and do indeed have some of that showing at this time; yet without these raised or bubbled film areas that also are evident throughout.

Again, thanks for the continued input.

Looks more like the top coat lifting from the sealer in those pictures. IS there still shiny finish under the areas that have peeled off or does it peel back down to the bare wood? the scenario; Floor is installed and sits for a few weeks and takes on a slight cup (edges raised). The floor is sanded flat then sealed and one coat. Final construction goes on then right before you moved in the final coat is put on. Now the floor has dried out a bit and returned to flat and when its buffed the edges are now lower and they dont get abraded so they now peel along the edge when the seasonal movement and traffic break them loose. Just a shot in the dark but it wouldnt be the first one ive seen it happen on.