Why is my finish blotchy?

[cathy comer]

I have refinished a lot of furniture. I love and have used Pratt and Lambert #38 finish. I am currently refinishing a cherry dining room table. I am using Pratt and Lambert #38 gloss finish, using a Gramercy Natural bristle brush. I applied the 3rd coat last night and this morning the top of the table is very blotchy. The 1st coat was dull as I thought it would be, the 2nd coat was some what blotchy but I thought with this last coat it would take care of any dull spots. Some areas are glossy, but some look dull. Legs are great but the top of table is blotchy. I lightly sanded between each coat of varnish and cleaned off the dust with paint thinner. I'm stumped, not sure what's going on. I've cleaned the brush with paint thinner, loaded the brush with paint thinner and then brushed out the brush, then loaded with varnish. I've used Pratt and Lambert #38 with out any problems for several years. The can of finish is 1 year old but has never been opened. Can some one please help me figure out what's going on? What am I doing wrong?

[Anthony Pantalone]

I'm actually going to be making some countertops out of cherry soon and I've been doing alot of research on how to handle it. I have found that cherry has a high tendency to blotch, even with clear varnish. The consensus seems to be to first apply a coat of zinsser's bullseye sealcoat shellac, cut down to a 1 pound cut, then apply the varnish.

[Prashun Patel]

That is not blotch. It is natural for the film to develop unevenly as the wood seals during the preliminary coats. Sand it with by hand with 320 grit. Wipe and vacuum the dust then apply another brushed coat. You will eventually get that even sheen you are hoping for.

Blotch on cherry is something different. That is varying degrees of darkness in patches. Fwiw I have never found clear varnish on cherry to be displeasing. For my money I would only worry about blotch if coloring.

The shellac seal coat that Anthony writes about can prevent blotch and seals the wood so that the varnish will build with fewer coats but now that you have started with the varnish you can just continue with it instead of complicating the regimen midstream.

[John TenEyck]

Exactly what Prashun said.

[Prashun Patel]

Cathy can u post a picture? I just thought of something. Could your surface be contaminated from the previous finish?

Are you experiencing the finish pulling away from areas? Have you started building a film but are seeing areas where the finish is not adhering?

In that case, it may be advisable to strip it properly or at least sand it a little more aggressively and apply a barrier, priming coat of dewaxed shellac.