Sticky coatings on Cocobolo?

[Rob Wilkins]

I've been trying to get some pieces coated over the last few weeks; using mostly a mixture of some Arm-R-Seal and Seal-A-Cell stuff, as some of it needs to be waterproofed. I don't know much about coatings and treatments, but they seemed like a good idea, and for the most part they've been working just fine.

The exception to this happy rule has been the cocobolo.

I have two pieces of cocobolo that I've tried in one case to coat, and in the other, to seal - but neither will dry. I only have one more, and I'm hesitant to do anything with it until I know how I'm supposed to end up with something decent at the end of it all. Where every other wood I've tried so far - purpleheart, bloodwood, cherry, birch, oak, mahogany - will coat nicely, dry nicely and be ready to sand in a day or two, depending on weather, these cocobolo swine simply refuse to dry. All they do is get sticky, then sit on the shelf, taunting me by being pretty and useless at the same time. The closest one has come to drying so far is getting so covered in dust that it's no longer exactly "sticky" so much as a bit of a mess.

The first question is - why?

And the second is - is there a better way to coat pieces that'll give them a glossy or satin coat, waterproof them, be resistant to general rubbing or light abrasion, and not turn into pretty fly-paper when it's applied to a piece of cocobolo?

(And third, I just realised this should probably be in the finishing section instead of here...blast...)

[Mike Wenzloff]

It's because of the nature of Cocobolo, a Rosewood family species.

It is the grain structure and the natural oils. The only thing I use on such woods is Rosewood or Teak oil. Light coats rubbed out well. And then perhaps wax.

Rosewood oil has greater UV protection, but the color will change over time and exposure.

Take care, Mike

***edit*** I take it back. On small lathe items I may do a BLO/CA glue finish.

[Rob Wilkins]

Thanks - that does make a lot of sense! I guess I'll try using something like the teak oil and wax polish then; clearly this coating isn't doing them any good. Now I just need to figure out a way of getting the coating off the pieces again to try and salvage them.

[Doug Shepard]

Yep - Ran into the same problem years ago with some kingwood (another Rosewood relative). After resanding down to bare wood and retrying a couple of things, what finally worked for me was putting on a couple coats of dewaxed shellac. Once that was on I could put almost any other finish over top of the shellac.

[Byron Trantham]

Another thing you might try is to wipe the surface with lacquer thinner just prior to applying anything. the lacquer thiner will help reduce the natural oil on the surface.

[Chris Padilla]

Byron's method also works well for gluing oily woods...teak is another good example.

[Rob Wilkins]

Probably worth investing in a few different things from this, then. Lacquer thinner, dewaxed shellac, teak oil...lots to play with. :-) Thanks to everyone for the replies!