Dominic Greco
09-30-2003, 12:28 PM
Hello Everyone,
Here are some picture of a big Walnut and Ambrosia Maple salad bowl I've turned a couple of weeks ago, but finally got around to finishing this past weekend. The bowl measures 14 1/2"OD x 4 1/2" high, and sports a 4" dia base.
Finishing this bowl turned out to be quite a bit more work that I had anticipated. The first time I sanded it, I was not pleased with the surface. So I wet sanded with mineral oil, thinking that this would help. Actually it made matters worse. It wasn't until I applied the finish that I saw how the end grain in one section of the walnut base had risen up. To my mind, it looked awful. Even though SWMBO says she couldn't notice, I could. And therefore I wouldn't let it out of the door.
Thinking that this was a problem related to my sanding method, I posted a question on Wood Central asking for opinions on dual action air sanders vs electric right angle sanders. I got some great input about these tools and after some thought, I have decided to purchase an air powered sander.
However, Russ Fairfield was one of the first people to respond to my post. He indicated that the problem lay not with my sanding tools. But with the way I was wet sanding. It seems that mineral oil may not be the best choice when wet sanding end grain in open grained woods like walnut. The slurry will fill the pores, but not make the fibers "stand at attention". If the wood fibers are not stiffened, they won't cut cleanly. Russ recommended wet sanding with a 50/50 mix of varnish and thinner (I used mineral spirits). The varnish should be the type with alkyd resins in it. The resins will impregnate the wood and stiffen it up nicely.
Well, after reading Russ' reply, I went to my local woodworking store and purchased a can of McClucky's Spar Varnish (in the red can). Over the next day or so I wet sanded the entire bowl to 1500 grit. This was a bit of a task since I had to use my vacuum chuck to hold the bowl on the lathe while I sanded. But in the end, it was well worth it. The surface was mirror smooth with no defects. Kudos to Russ!
After allowing the bowl to dry off, I applied a coat of Woodcraft's Urethane Oil finish. Afterwords the bowl was buffed with the Beall System, minus the white diamond. Even though I pretty much sealed the pores with the varnish/mineral spirits mix, I was still cautious about the effect of the white diamond compound would have on the walnut. Sometimes the white compound gets trapped in the pores of the walnut and ruins the effect.
And just for your amusement, here is a pic of a 4" dia sphere I turned from some spalted red oak Mark Kauder sent me last year. He actually sent me a 10" dia bowl blank, but it cracked after sitting for too long. But cutting out the crack at my bandsaw, I was able to get (3) small blanks from it. I was pretty amazed at the color and figure this wood presented. I would have never expected this from Red Oak.
Thanks for viewing.
See ya around,
Here are some picture of a big Walnut and Ambrosia Maple salad bowl I've turned a couple of weeks ago, but finally got around to finishing this past weekend. The bowl measures 14 1/2"OD x 4 1/2" high, and sports a 4" dia base.
Finishing this bowl turned out to be quite a bit more work that I had anticipated. The first time I sanded it, I was not pleased with the surface. So I wet sanded with mineral oil, thinking that this would help. Actually it made matters worse. It wasn't until I applied the finish that I saw how the end grain in one section of the walnut base had risen up. To my mind, it looked awful. Even though SWMBO says she couldn't notice, I could. And therefore I wouldn't let it out of the door.
Thinking that this was a problem related to my sanding method, I posted a question on Wood Central asking for opinions on dual action air sanders vs electric right angle sanders. I got some great input about these tools and after some thought, I have decided to purchase an air powered sander.
However, Russ Fairfield was one of the first people to respond to my post. He indicated that the problem lay not with my sanding tools. But with the way I was wet sanding. It seems that mineral oil may not be the best choice when wet sanding end grain in open grained woods like walnut. The slurry will fill the pores, but not make the fibers "stand at attention". If the wood fibers are not stiffened, they won't cut cleanly. Russ recommended wet sanding with a 50/50 mix of varnish and thinner (I used mineral spirits). The varnish should be the type with alkyd resins in it. The resins will impregnate the wood and stiffen it up nicely.
Well, after reading Russ' reply, I went to my local woodworking store and purchased a can of McClucky's Spar Varnish (in the red can). Over the next day or so I wet sanded the entire bowl to 1500 grit. This was a bit of a task since I had to use my vacuum chuck to hold the bowl on the lathe while I sanded. But in the end, it was well worth it. The surface was mirror smooth with no defects. Kudos to Russ!
After allowing the bowl to dry off, I applied a coat of Woodcraft's Urethane Oil finish. Afterwords the bowl was buffed with the Beall System, minus the white diamond. Even though I pretty much sealed the pores with the varnish/mineral spirits mix, I was still cautious about the effect of the white diamond compound would have on the walnut. Sometimes the white compound gets trapped in the pores of the walnut and ruins the effect.
And just for your amusement, here is a pic of a 4" dia sphere I turned from some spalted red oak Mark Kauder sent me last year. He actually sent me a 10" dia bowl blank, but it cracked after sitting for too long. But cutting out the crack at my bandsaw, I was able to get (3) small blanks from it. I was pretty amazed at the color and figure this wood presented. I would have never expected this from Red Oak.
Thanks for viewing.
See ya around,