PDA

View Full Version : Cocobolo



Lee DeRaud
09-05-2005, 2:06 PM
I've got a serving tray: 1/16" cocobolo veneer over 3/8" birch ply, wenge border, jarrah feet. Using my usual GF SealACell/ArmRCoat combo, the wenge and jarrah are coming out very nicely, but the top-coat doesn't seem to want to cure on the cocobolo: 12 hours and it's still tacky. So strip with MS, scrape, sand, repeat...no joy.

Note that I'm talking thin coats: I can get a coat to cure, but only by wiping it so hard I almost can't tell it's there afterward, but at that rate it will take 10+ coats to get something resembling an even finish. Any clue what's going on here?

(Plan B is to strip it one more time, let it dry a couple of days, and just shoot it with clear lacquer. Anything in particular I should watch out for?)

Mark Singer
09-05-2005, 3:04 PM
Some woods like cocobola seem to do better with wax only because of the oil

Lee DeRaud
09-05-2005, 3:14 PM
Some woods like cocobola seem to do better with wax only because of the oilThis is the first time I've used cocobolo for for anything bigger than a pistol grip, serves me right for not testing the finish first.:mad:

Just tried the wax-only approach on one of the other panels: it's not bad, just not anything close to as striking as the oil/urethane mix. I would have already given up on it if it didn't look so good.:cool:

(And how is it spelled, exactly? Doesn't look right without an "a" in there somewhere, but the "all-o" spelling is the only one that got hits on the Woodworker's Source search.)

Michael Stafford
09-05-2005, 5:04 PM
Lee, I have always spelled it cocobolo, the all O version. I have found that you can finish cocobolo with and oil/polyurethane mix thinned very thin with mineral spirits and put on in multiple light coats buffed dry as soon as practical.

Here is a cocobolo box I finished that way.

Lee DeRaud
09-05-2005, 5:31 PM
I have found that you can finish cocobolo with an oil/polyurethane mix thinned very thin with mineral spirits and put on in multiple light coats buffed dry as soon as practical.Thanks. That looked like it might work, it was just that "multiple" appeared to be getting into double-digits, well past my comfort/patience level without some guarantee that it would work. I'll stick with it awhile longer.:eek:

Phil Winn
09-05-2005, 8:25 PM
Be careful with the wooddust.....I use WATCO to finish it; works well for me!
Phil

Steve Schoene
09-06-2005, 12:05 AM
I haven't worked with cocobolo but whenever faced with an adhesion problem my first thought is DEWAXED shellac such as Seal Coat. After a coat or two the shellac just about any other finish should stick. Besides I like the look of shellac, which has lots of variations between Super Blonde and Dark Garnet.

Ben Abate
09-06-2005, 5:57 AM
Lee,

From personal experience with oily woods I will normally wash the surface with lacquer thinner. Let it dry which does not take too long, then give it a coat or two of shellac. Afterwords you can put any finish you would like on it. The proplem seems to be the oils keep coming to the top after the wood sits for a while after you remove the finish. I have made a few humidors out of Pauduk and I had this problem with one that I wanter to throw in the fire wood box. Then I tried the wash coat of lacquer thinner and it worked fine. Just remember to have all the items ready to go, don't give it time to release the oils before you get the shellac.

hope this will help you
Ben

Lee DeRaud
09-06-2005, 6:53 PM
Thanks for the suggestions. I have three more of these panels to try various things on.

For the one I originally posted about, I went with "plan B": stripped it with mineral spirits, some scraping, and shot it with spray-can clear gloss lacquer, then 0000 steel wool and paste wax...photos over in the "general" forum.

Dave Anderson NH
09-07-2005, 3:34 PM
I had the same problem the first time I made marking knife handles out of Cocobolo. My current protocol for finishing is 2 coats of Zinnser Sealcoat shellac followed by my standard Waterlox Original finish. The sealcoat shellac acts as a barrier to the oils in the Cocobolo which interfere with the finish curing.


If you prefer a close to the wood finish without a film buildup, BLO cut about 1/3 with either mineral spirits or naptha works very well. My proceedure is to flood on the finihs, let it sit 15-20 minutes and briskly wipe off all of the excess. After two coats with 3-4 days of dry/cure time in between, I apply 2 coats of paste wax letting each coat sit half an hour before buffing with a soft cotton cloth. Both of my Shepherd infill plane kits with Cocobolo infill have been finished this way and they are a joy to handle.

Howard Acheson
09-07-2005, 4:45 PM
As others have already said, cocobolo is a wood that does not get along with oil based finishes. It is loaded with oil naturally and this oil will impede the drying and curing of oil based finishes. Sometimes, wiping with lacquer thinner or alcohol and drying with paper towels will get rid of enough surface oil to let an oil based finish harden. But, oil based finishes dry so slowly that the oil from the cocobolo seeps back to the surface before the oil based finish has a chance to fully dry.

The best approuch is to first coat the surface with shellac or lacquer. Both will adhere to the surface and dry quicky. After that pretreatment, you can apply an oil based film finish--but not a true oil or oil/varnish product.