>First try at posting a picture. This is a small redwood burl platter/bowl about 8 inches across and 1&1/2 inches deep. Currently sanded to 1200 grit, but no finish.
I normally use an oil finish, but when I tested my normal finish on a cutoff of the redwood, the oil darkened the wood so much that the flecks, rays, and grain flutter pretty much disappeared. As a result, I am thinking about a wax finish. Does anyone have any thoughts or suggestions for finishing redwood burl?
I have the same problem. I was given some old growth redwood that was used for cane berry stakes, 12x6" squares. I've tried everything to get the sanding scratches out and nothing has been succesful; going through all the grits down to 1500 stil leaves marks.
With the finish, the wood is so porous that it's impossible to get oil or sanding sealer on and have it blotch free. I have not tried just polish. Maybe Mr. Finish, Russ, will weigh in on this one for us.
>Your problem stems from the material being a soft wood, which is, in turn, compounded by the burl which will produce wildly varying densities. Since wax cannot penetrate wood (molecules are much too big), it will not blotch up on you; it's got little or no durability however.
I'd tend to suggest that, before you try any other finish, you both try to condition your pieces' porosity with de-waxed shellac. You can use "mix-your-own" dewaxed Ultra Pale if you want a "damp" look that dissappears when dry and gives minimal color charge, or you can pick up some Zinsser's "SealCoat" which is the same thing, just premixed. You will, however, need to dilute the mix to 1/2 pound cut or less. In Zinsser's case, that would be 3 parts fresh alcohol to 1 part from the can. If you're mixing, put 2 oz. of flakes in a quart of alcohol.
Flood it on the surface by brush and allow to dry. You can add a few drops of pure gum turpentine to retard the drying and allow deeper penetration into the wood. When dry (overnight), hand-sand very lightly with 600, vac off, and apply a second application of the same stuff. You should notice that there will be far less color change with the 2nd application, which will then even out when dry.
You should then be able to proceed with your favorite finish without much color change or the other problems you describe. Suggest you try this on some scrap from the same wood before taking on your primary piece.
I really like this bowl. I like the shallow dish in it. I turned a piece of figured redwood last fall and I was disappointed in what the Danish Oil finish looked like afterwards. I wish I would have used beeswax or some other type of finish.
I've just done (in the last few months) 3 bowls from redwood burl. I had really good luck using "Tried and True" varnish and then going through the 3 step Beall Buffing system. The oil did darken the wood some, but I also felt like it made some of the features really stand out. I loved turning that stuff. I have one more small piece but am wishing I'd bought all my local guy had when we had it!
Great looking bowl, let us know how the finish turns out.
Mike
Lathe time taking a hit as flat work rules (for now) in Apex, NC!!
>As mentioned by Russ, wood will darken one way or another aand he recommends varnish in his post below. I personally still have a long way to go before I'll use varnish.
I offer two suggestions that you can try on a test piece and see what your results are. Method one is Mylands sanding sealer that I used thinned as per Chris Stott's instructions. Cut back with 0000 steel wool and then use Mylands melamine. I use this on my dyed pieces and this protects the colors from bleeding while at the same time preserving the original colors and displaying chatoyancy. The second method is the favorite of most woodturners is pure tung oil. Dilute with mineral thinner 50/50 and use this for the first 2-3 coats. This is thinned for absorbtion into the wood. The last 1-2 coats is done with pure tung oil. The down side is 1-4 days between coats. I find this the most superior finish that protects the wood while leaving it in its almost original state. Both finishes above use 0000 steel wool between coats and normally the last coat isn't cut back. Both can be Beal buffed, too.
>This isn't the only way to put a finish on these porous woods, but it is what works for me. I use this method for finishing large pieces that are turned from Western Red Cedar and Redwood burls.
The wood is turned to its final form and thickness and rough sanded while it is still wet. I use Aluminum Oxide paper from 60, 100, and 150 grits. The grit comes off because the adhesive holding it on the paper isn't waterproof. It will still sand the wood, but water and a scrub brush may be necessary to clean the wood between sanding grits.
The wood is allowed to dry for no more than a day or two to get rid of any free water that may still be in it, or to get rid of the water that was added with the wet-sanding.
Then it is placed in a tub filled with enough of a home-brew oil/varnish mixture to cover the wood. A brick will keep it submerged and I cover it with some plastic film (usually grocery bags) down on the liquid surface. Leave it soaking until until all of the water in the wood has been replaced with the mixture. This will take several days to several weeks.
The piece is removed from the tub and set aside to drip dry until the oil and resins in the wood have cured. Again, this will take several days to a week or two.
When all of this has dried, the wood is put back in the lathe and given a final sanding. This is a wet-sanding, using the same "finish" as a lubricant. I start sanding with 150 grit and then go to wet-dry silicone carbide papers through 320 or 400. The sanding slurry will fill in all of the little voids remaining in the wood surface.
Then I reverse it and finish the bottom. A higher gloss can be brought out with a buffing wheel.
I also make a lot of weed-pots and other small things from dry pieces of these same woods, and use this same finish for them. The only difference is that the dry wood is finish sanded on the lathe and then thrown into a pot of finish where it will soak for at least an hour to no longer than the end of the day. Then it is allowed to drip dry, wet sanded with the finish to fill the grain if required, allowed to dry again for a couple days, and buffed with a home-made version of the Bealle buffing wheels.
This isn't a finish for someone who is looking for "Instant", but the results are worth the wait (my opinion).
The Finish....
1-gallon Boiled Linseed Oil
2-gallons Unscented Mineral Spirits
1- quart of a good quality varnish. I use McCloskey's Gloss Spar in the red can.
Add 1/2-cup of Japan Drier if you want it to cure faster when the shop temperatures are below 65F at night.
Use smaller amounts in the same proportions if you don't want 3 gallons of finish. This is not an ideal finish, but it is inexpensive, and just a good as Watco or other Danish Oils. Tung Oil is better than the Boiled Linseed Oil, but the cost difference isn't worth it for a dark wood.
I have not found another finish that will bring out the grain as much as this one. These species tend to come apart with age, but the cured oil and resin will keep them together.
This a photo was clipped from the video that I am making on finishing turned wood. I shows what can be done with Western Red Cedar Burl.
