Cocobolo finishing for drink coasters?

[Mike vonBuelow]

Newb to wood here - but I found a nice piece of cocobolo I'm making some drink coasters out of and going to laser engrave for a family gift - 1/4" thin if it matters.

Plan was to sand to 600, then laser, fill with gold leaf paint, then a coat or two of semi-gloss poly for water repel.

Any issues that anyone sees with that plan?

Thanks in advance, from a laser head.

[Curt Fuller]

Not sure what you mean by water repel, but the poly will probably give you problems with cocobolo. Cocobolo is such a naturally oily wood that the poly finishes just won't dry on it. I've always just used a light coat of oil and buff on coco but that wasn't for a waterproof finish. A lot of the pen turners use a CA (superglue) finish with success on coco. Hopefully one of them will respond with their process.

[Mike vonBuelow]

Do I not need a water repellent for condensation from drinks??

Again, total newb to wood - e.g., just now read all the warnings re: its dust - after 30 min of sanding with belt/disc sander. (eek!)

[Bernie Weishapl]

I have wiped down coco with acetone and then finished with lacquer. Works pretty well for me when making coasters. I also use a cork insert on my coasters.

[Jim Burr]

Maybe an oil finish for an oily wood Mike? Try some AO on one and see what happens and try buffing the AO as well. If you want to CA it...wipe it down with some kind of alcohol...DNA, Isopropol...whatever. Let that evaporate and spin on your CA. You will be doing a lot of coats to keep the oil contained...10-12. Wet sand after about the 6th coat and the last one. Polish with whatever you would normally use.

[Mike vonBuelow]

I also use a cork insert on my coasters

I was hoping I didn't have to resort to cork... as I'd like the family crest to be engraved/color filled on top.

[Tim Rinehart]

Mike, Can visualize your dilemma. Since you don't want to use cork, you do realize that any moisture is going to just sit on the coaster and hydroplane a cool glass of lemonade sitting on it, right?
If these are more of a 'hot drink' or wine glass sort of coaster, then the finish isn't going to matter much or be important, I don't think. The cocobolo will buff out nicely on it's own, it has lots of natural oils, and you could just enjoy them in their more natural state.
All that aside, I too had tried to put a poly finish on a cocobolo piece years ago...no success. I ended up removing it with naptha and just buffed the piece out.
The CA finish thing may be problematic with your laser/leafing...and if you want to protect just the areas that were leafed, Bernie's suggestion with the lacquer (wipe on I would think?) seams reasonable, especially if area of interest is mostly just the crest area. For that matter, if protecting only the leafed area...poly would be fine too...but the lacquer will probably maintain the color best without imparting any amber hues.
Just my $0.02...look forward to seeing them!

[Montgomery Scott]

Do not use any finish. You'll just get water marks in the lacquer and ruin the finish. Cocobolo is virtually impervious to water damage so you are better off not to use anything.

If you really want a finish on it you could look into Crystalac or a similar waterbourne finish and see if it is waterproof. Another option would be an epoxy finish if you want to go through the trouble.

[John Beaver]

I have studied this quite a bit. Here is what I believe.

Due to the high silica content in Cocobolo it is very risky to add any finish. Likewise the silica gives a nice finish when just polished.

Most of the advice you have received is correct. Do not finish it with any oil based finish, as it will possibly separate from the wood over time. Oils also tend to darken the wood more over time.
Poly finishes do not adhere well either.

If you feel the need to put something on the wood, begin with a naptha or acetone wash, and then a few coats of shellac. It does work to put a lacquer over the shellac as the shellac will help the bond.

When I have wanted to fill the pores in the cocobolo I have just used multiple coats of shellac and left it as that. If you intend to use the piece, I would add the lacquer as the shellac is not a durable finish.
__________

As far as the allergic response. People say you are either allergic to cocobolo or will be. I am able to handle it fine still, but I do recommend using a respirator and skin covering.

[cal thelen]

As far as engraving on a CA finish, I have had pens that i CA finished engraved and they turned out real good

[Ryan Baker]

I'll echo the previous comments. Don't put any type of oil or oil-based finish on cocobolo ... it just makes things worse. I don't do anything with cocobolo any more except polish it up and wax it. If you really want to try a poly finish, use water-base poly, not oil-based. (Wipe it down with acetone first to remove surface oil.) I have been able to make water-based poly work, but there's always the risk of the finish coming off in sheets later from not adhering.

Nothing will really protect it from the water anyway. You are probably just as well off to just wax them, and then buff them out again when they need it.

[Joe Ruden]

CA can be very difficult to use on cocabola. I have had to redo many pens due to the oil in the wood causing cloudiness after the CA has been put.

[Mike vonBuelow]

Thanks for all the replies.... will post pics once I get ready to laser engrave the crest.

As for now, it's sanding time :(

[Mike vonBuelow]

1st pass at 220 gt & rinsed to show colors - now off to Lowe's to get some 600 gt and look for water-based options.


241420

[Ken Glass]

Mike,
I would use Penofin Rosewood oil on it. Since Cocobolo is so dense that's the only thing I can use that penetrates the surface well. I use it on custom Adirondack chairs that I make from Ipe. It will repel water and it really brings out the grain and natural color of Rosewoods. You may have to re-coat after several months of constant use, but it does last outside for 2-3 years.