What tha ?

[Larry McCully]

OK guys, see if you can help with this one.
I just reciently sanded a floor that had been sanded a few times before. All went well except for these rejection spots around some but not all nail locations. The proceedure i used was:

Level sand
punch down and putty up
Putty mix was filtered dust from the machine mixed with sealer, Normally i use timbermate, but on this job the client wanted to fill large gaps. So at the same time i filled the nail holes with the same mix.
fine sand
polyvac with 120 sanding disc
polyvac with 120 screen
Fast seal first coat from urethane coatings
2nd coat- Purathane single pac satin (Urethane coatings)
Detail putty to missed holes using timbermate.
Polyvac with blue water base abrasive pad between coats
3rd coat purathane satin. (Urethane coatings)
The client requested that he changed his mind with satin and wanted gloss
polyvac with blue abrasive pad
Applied the gloss
WHAMMO, REJECTION AT NAIL HOLE


They have a old dog, blind and loosing massive amounts of hair, Standard rooms, Brushbox hardwood floor, Previous sanding had waterbase on it , prior to that sanding, they had tung oil buffed in. Large gaps between the boards.

I am stumped, but i have an idea. I want to see what Dusty and other pro's out there think about it.
90832

[Dusty]

I think it looks kinda' pretty. And, I'm guessing the owner doesn't agree - right?

To be honest, I don't have a freakin' clue what it is. Perhaps, a reaction from the oil and water from the two previous sand and coats. We all know oil and water don't play well together. Other than that, Larry, I give up.

[chrisp]

Just as a long shot guess, maybe the floor was polished with a silicone wax at some stage and some of it may have soaked in to the timber via some of the nail holes?

[denaria]

Ammonia dog pee reacting to metal.

[Larry McCully]

Bingo, i think you got it. Did you notice the black reaction around the nail hole. That means moisture of some sort. I did read about urine. Its under the bed areas as well as i have been told.
Ammonia dog pee reacting to metal.

[Bloss]

In which case sodium bicarbonate might be the go - a bugger as you have to lift those spots and feather back etc.

[Levey]

In no way is this your fault,

If the owner is OK with the blackness around the nails (due to probably the dog) then I'd solvent wash the floor, cut it back and recoat it using flow-add and a dash of Wet edge extender in the mix.
If he is not happy about the blackness then he should pay for board replacement where required and resanding.
Thats just my opinion!

[Larry McCully]

Thanks Levey for your thread. TRhe owner is extreemly understanding and is allowing us to work through it with him. I have done some research and have asked a brilliant chemest who manufactures polyurethanes, and he has identified it as a "Opaque water bloom". It is water migrating up the stem of the nail and depositing itself on the top. I have not sen it before. The water breaks down the polymers in the polyurethane and causes it to chaulk. Very interesting.

[Levey]

You never stop learning in this industry it seems, hope it works out ok in the end.