Q: I inspected a job today where the oil poly was pushing up through the seams. The sanding was done in Feb., there was heat in the house. It was a sand, sealer and two coats of oil semi gloss. No stain? I am going back in August to resand, this time using waterborne product. I want to determine why the poly is pushing up before I do it over and have it happen again. The moisture reading was 6%. Red oak #1.
A: That has happened to me once in 40 years. It is a disappointing event to be sure and is partly just bad luck. You will need to keep wiping them off (if they are wet) or chipping them off with a putty knife if hard and keep doing that until it has stopped. I attach a short article about this condition called poly balls / polyballs. It deals with gym game line paints and polyurethane involved with this problem.
Follow-up Q: The poly is hard. Would a screen and coat fix the issue, or a complete resand?
A: I would try a screen and re-coat but I think I would try and scrape any bbâ€™s down a bit. You know, if they get stuck on the bottom of the screen what is likely to happen. Major scratching and swirl marks.
Follow-up: I agree. Thanks for all your help!