I have been doing a lot of paneling and built-in cabinet work using #2 pine. I've had a problem with areas of top coat delaminating (I think) and turning whiteish. I have tried various finishing techniques but the problem persists. I have attached a photo that give a representative sample of what the problem looks like. Some of it is much worse and more widespread.
I was initially using my tried and true finishing process. Minwax stain followed by Woodline Polyurethane. I typically thin the first coat about 10% with turpentine. After the first coat I sand with 320 to knock down any roughness and then follow up with a second and third coat. I try and recoat within 24 ours, or I scuff sand the prior coat with 320 if its been more than 24 hours. The delaminating tends to get worse with every coat no matter how long I let it dry and whether or not I scuff sand between coats.
Thinking maybe it was the poly, I tried another brand (Parks) and had better results, but the problem did still persist.
I thought maybe the issue had do be with the way I stain my work. I try to match my work to existing 60 year old pine that tends to run a soft "colonial maple" color. I probably use too much stain as I let the surface stay "wet" rather than wiping it down in order to get the right matching color. I thought maybe that was causing the delamination so I switched to water based stain.
The problem got better, much better in fact, but it did not go away.
I next tried switching to lacquer. Again, it was generally better better but still an issue in some areas. In fact the picture I posed is water based stain followed by nitrocellulose lacquer (Mohawk).
I should note that with the poly, the problem shows up within 24 hours although it does get worse over time. With the lacquer, it didn't start to show up for weeks. I should also note that I'm in interior California where the humidity is pretty low. I've had the problem happen in all kinds of weather; hot, below freezing, raining, dry, ...
I do a lot of work in oak, alder, and occasionally in vertical grain Douglas fir. I don't have this issue with any of those materials, even with my Minwax layered staining technique. So the only thing I have not changed is the pine. Not using pine isn't an option since I'm matching pine. There has to be away to finish pine without this occurring.
Any ideas what is causing this? Anyone else experienced this problem? Any suggestions on how to avoid? I have considered using shellac between the stain and the top coat, but some of this work is in bathroom and I don't like the idea of shellac as an undercoat.
One more thing, I've had this happen with pine from a stack of fresh lumber at my wood supplier as well as packaged pine wainscoting from a home store.
Mike