Hey All,
We have a flooring problem. A newly laid Red Oak floor with an oil based stain ( A mix of three different stains to get a “custom” color) with water based poly as a final finish. The polyurethane is coming up in sheets! I would appretiate all opinions.
John
Replies
Water based polyurethanes are sensitive to what's underneath them. They don't like dirt, grease, stearates, etc.. They also need sanding between coats to provide a key for subsequent layers.
It sounds like the oil based stain wasn't fully dried before the poly was applied, and it couldn't adhere. After the staining it would have been prudent to seal the oil base with a super blonde dewaxed shellac to create a barrier and to which the poly does adhere well to after a light sanding. The alternative would have been to wait a lot longer for the solvents in the oil stain to evaporate, but I prefer the dewaxed shellac sealer route myself.
I'm not sure if you could have used a vynil sealer in this circumstance. I've only ever sprayed this stuff and don't know if there's a brush on version. I'm also not sure how water based poly adheres over vynil sealer having never attempted it. I'll continue with what I know works until I hear different-- the dewaxed shellac.
It's too late now, but the only fix I can think of is to strip the job completely and do it again.
Hopefully others with specialised knowledge about finishing or polishing such as Woodwiz or Kevin will spot your message and have a better solution. Slainte.
I feel for you because this sounds like a do over or at least a big fix. Obviously there is an adhesion problem. Most likely the stain was not completely dry, it may have felt dry to the touch but oak has deep pores and for some of us it's Spring with increased humidity. Dry time increases with extra coats. There is a possibility that you made or used an incompatable mixture, all oil stains are not the same and you were not very specific regarding what you actually used. Waterborne poly should go over a stain that is dry and not waxed or siliconized. It will not go over products that contain stearates and is not recommended over shelac or lacquer. Most manufacturers recommend using their products throughout the process. Finding out what is actually in the product can be tough, MSDS sheets have some of the info, ask for one when purchasing. I personally think there is a risk when you start mixing products from different companies. Minwax for example is a woodfinish not just a stain. I would hesitate to use that and then topcoat with Zip-guard waterborne poly. Safer to use Zip-guard stains.
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