Finishing Walnut

[Greg Just]

I recently completed a hummingbird feeder in which I used walnut for the top. I applied Minwax Spar Varnish as this feeder will be outdoors. The problem is that even after 3 plus days, the finish on the walnut has not dried. It has dried on the maple and cherry. This is a new can of varnish and I was sure to mix throughly. This was kiln dried wood, so moisture should no be a problem. Any thoughts? :confused:

[John Keeton]

Greg, I have had occasions where WOP will not dry for no apparent reason. Usually, I wipe it off with MS and leave it a couple of days and then re-apply and it does fine. Walnut is a much more porous wood than either cherry or maple, so I suspect a lot of it soaked into the walnut and thus is not exposed as much resulting in slower drying/curing.

Spar Varnish is a long oil varnish meaning it has more oil content. That may exacerbate the problem.

[Hilel Salomon]

I love walnut but have had very little success with it in turning. When I've made furniture with walnut, I've always used a darkened filler before applying any finish. I apply the filler and almost immediately start wiping off the excess with pieces of burlap. After it is dry, I sand lightly and then apply finish. If I use varnish, it is over the stain.

[Bernie Weishapl]

Greg I have had the same thing happen occasionally. I do like John said and wipe off with Mineral Spirits. I let it sit in the sun to dry for a day or two then reapply. Don't have a answer why but it works.

[Marty Eargle]

Same as John and Bernie...clean off the tacky finish and try again.

[Russell Neyman]

As a former Valspar employee who dealt with their gym finishes, check the batch number. Somewhere within the numbering system will be the year and month it was manufactured, and the practical shelf life is usually one year. Typically, a manufacturer will use the first number or two for year, and the next designation will be the months. Old, outdated stock can sit on shelves for years past their expiration date.

If the problem is something inherent in the wood -- like an oily piece -- the aforementioned wipe-down with mineral spirits is smart and can't hurt. An even safer technique is to apply a seal coat of clear shellac, sand lightly, then apply your topcoat. To my eye the shellac enhances most grains, especially walnut.

[Greg Just]

An update to this thead:

I contacted Minwax and their suggestion was what others had said. They thought that a film may have formed on top of the Helmsman which trapped the solvents underneath and to wipe over the soft or tacky areas with 100% mineral spirits. They also suggested a blow dryer on a low setting over the finish to speed up dry time and I did try that but it didn't help. I still wonder why this only happened on the walnut and not on the cherry or maple.

[John Keeton]

Greg, I would think the porosity of the walnut causes the varnish to "pool" in the open pores of the walnut vs. the relatively tight grain of maple and cherry. Maple or cherry will "build" a finish much faster than will walnut for that reason.