Wipe-on finish problem

[Mick Funkhouser]

Let me begin by saying that I am somewhat of a perfectionist, which is not much different than most of you here on this forum. Yes, I have been reading here for weeks, and seeing that there are many of you who are measuring tolerances to the ten thousands of an inch on the adjustments of your equipment - I can not come to any other conclusion - most of you are somewhat like me! "Perfectionists". Okay, to my problem.

I am in the process of finishing a small box constructed of Black Walnut which I have had "curing" for the past twenty-five years. I am using a wipe-on finish (Homer Formby's Traditional Tung Oil Finish - High Gloss), and just applied the thirteenth coat. These "coats" of course, are thin - maybe too thin, as the grain is still not filling in to my expectations. My first question is: How many coats might be needed before completely filling in the grain? Let me fill you in as to what, and how, I have done so far:

After construction, I began sanding with 100 grit paper and graduated up through 600 grit wet or dry using high quality paper. I then wiped down the wood with a damp cloth allowing the grain to "stand up" - sand smooth again, and repeated until the grain felt smooth after drying. It took three or four times of dampening down and resanding to accomplish this task. The wood was so smooth after finishing the sanding, that gravity almost made it difficult to hold the box between my hands. Yes, just really smooth. I then applied one coat of walnut stain/wood sealer which I wiped thoroughly after a couple of minutes and let dry completely for a couple of days. I have since been applying one to two coats per day for the past eight days, lightly rubbing down with #0000 steel wool or 600 grit wet or dry paper between every one or two coats - depending on the gloss.

At present the grain stands out beautifully, and I couldn't be more pleased with the looks, but the finish is not filling in as quickly as I had expected. Am I expecting this to happen too quickly? How many coats will I need to apply? Am I doing this right? Have I missed something in between?

I have made a few boxes before, but have never used the "wipe-on" finish, so don't know exactly what to expect to attain the "glass like" finish for which I am striving.

I know there are several experts out there who know how to do this, and hope they will come to the rescue. I know I can attain the desired look by brushing on a couple of heavier coats or by spraying, but I don't want to resort to either of those fixes. I am also willing to apply thirty or more coats if necessary. Thank you for the expected help.

This is a great forum, and I am glad that I stumbled my way around and found it. You are a great bunch of guys and gals. I have learned a lot by reading here.

Thanks again,

Mick

[Larry Fox]

For walnut I typically fill the grain before I start applying finish (I typically use pumice and BLO). I imagine that with enough coats the grain will fill with finish but I don't know what the definition of enough is in this case.

[Howard Acheson]

Formby's is a thinned wiping varnish. There is not much in the way of solids so once the thinners evaporate, you are left with a very thin film. Because there is so few solids, it takes many coats to fill the pores.

As has been said, Walnut is a somewhat open pored wood and if you want a perfectly smooth "piano-like" finish, you would have been better off to use a grain filler as your first step. At this point, you have two choices. Continue to apply the Formby's but stop sanding between the coats. BTW, don't use steel wool. It rides up and down over irregularities without flattening them Use 320 sandpaper on a hard rubber sanding pad. This will flatten the surface. Your other choice is to use a full strength varnish and apply one coat with a brush. This will establish a much thicker film filling in the pores. Let it fully dry and then flat sand it with your 320 paper. Then put on a final coat of the Formby's and you should be done.

For the future, let me suggest some things that will save you some time. First, sand only to 220 grit initially. Sanding to any higher grit will not give you a smoother finish when you apply your finish. You can also avoid "raising the grain". Any first coat of finish will somewhat cause wood fibers to rise due to absorbsion of the finish into the wood fibers. So, instead, just apply your first coat of finish thinned 50/50 with mineral spirits. When it dries it will have a somewhat rough feel. Don't worry. Use the 320 paper and a sanding block to sand the surface flat. It will sand easily because the finish was thinned. Now you should have a smooth surface ready to accept your finish. Apply either one full strength coat or two thinned coats. Let this fully dry for 24-48 hours. Now sand this with 320 paper, vacuum and apply a couple of more coats. That should do it and it should fill the pores in the wood.

You've made the finishing process more difficult and time consuming than it needs to be.