Decal On Cocobolo With Oil Finish Problem

[jaycee]

I normally use water slide decal with a varnish on top, with enough layers to have a smooth finish. This time however the varnish is not taking to the Coco' because of it's oily nature, what do you recommend I use instead apart from inlays (as I don't have any inlaying equipment).

I will be finishing the headstock with Danish oil.

I was thinking of a permanent marker and writing the name on.

[ScottR]

One option would be to burn it in.

SR

[jaycee]

I just bought a pyrography set this week, so I am trying that out. takes a bit of getting used to tho'. I burns well on Ash, Spruce and Obeche but the Coco is a bit trickier, lots of smoke due to the oils I think.

Once i get a bit more proficient it's something that I will consider.

[avengers63]

Coco is one of the most oily woods there are, and it's a royal PITA to finish. BUT... if you get it right, it's well worth the effort. The big thing is sealing in all those oils. If you don't, they'll come to the surface and screw up whatever finish is put on. Oil finishes are meant to penetrate into the wood. They won't work with coco, so don't waste any more time/effort/product trying to make it work.

1) Get off everything you have on there right now and start with a "clean" surface.

2) THOROUGHLY clean the coco with acetone. This will take away all of the surface oils and just enough from below the surface to let you seal the rest in.

3) Seal the coco with shellac. It's the only thing that will cure and seal in the oils. As a bonus, shellac sticks to everything, so whatever finish you put over it will work... except oil. If you want a more natural looking & feeling surface, you'll need to lightly sand the shellac and just put on a 2nd or 3rd coat.

[jaycee]

Coco is one of the most oily woods there are, and it's a royal PITA to finish. BUT... if you get it right, it's well worth the effort. The big thing is sealing in all those oils. If you don't, they'll come to the surface and screw up whatever finish is put on. Oil finishes are meant to penetrate into the wood. They won't work with coco, so don't waste any more time/effort/product trying to make it work.

1) Get off everything you have on there right now and start with a "clean" surface.

2) THOROUGHLY clean the coco with acetone. This will take away all of the surface oils and just enough from below the surface to let you seal the rest in.

3) Seal the coco with shellac. It's the only thing that will cure and seal in the oils. As a bonus, shellac sticks to everything, so whatever finish you put over it will work... except oil. If you want a more natural looking & feeling surface, you'll need to lightly sand the shellac and just put on a 2nd or 3rd coat.

Before I read this post, I used lighter fluid and varnished over the top, which cured to a certain extent but is still very soft after 24 hours. Will get some acetone and Shellac over the weekend. Let you know how it goes. Thanks

[avengers63]

I'm not joking about really getting in there with the acetone. Try and work it until the cloth hardly picks up anything.

For the shellac, know that it has a shelf life. Try to look for clear, not regular or amber, and look for the most recent date of manufacture on the can. It really starts to crap out on you if it's not used within 3-6 months.

[Mr Natural]

Coco is one of the most oily woods there are, and it's a royal PITA to finish. BUT... if you get it right, it's well worth the effort. The big thing is sealing in all those oils. If you don't, they'll come to the surface and screw up whatever finish is put on. Oil finishes are meant to penetrate into the wood. They won't work with coco, so don't waste any more time/effort/product trying to make it work.

I totaly agree with your statements about prepping Cocobolo- but I just want to note I have had success with Watco Danish Oil on cocobolo. I have a Carl Thompson style bass I made 7 years or so ago- and the center block is made of cocobolo- and it hasnt leaked or fudged up at all. Like you said- its all about the prep. I would add to your prepping that once it seems to be cleaned up with the "acetone bath" (literally) and the cloth is all but clean, let it sit for a week and do it again. If there was "considerable" oils from the first swipes the second go round- Then let it sit for another week- typically the third time is the charm. ( I had to do it three times for that thick center block). At the time I did a test side by side with cutoffs using Watco vs I think Forbees and maybe Minwax Tung oil (blend - not pure Tung oil)- and both Tung Oils took (literally) 6-8 weeks to cure hard. They were sticky for weeks. The Watco was dry in like one day- maybe 2 at most. That first coat of Watco has to go on heavy- let it sit and soak in, then wipe it off. 2 more light coats using steel wool and its done. A little wax and it shines up nice. Easiest finish I have ever used- but the prep has to be done like you said.

I am not sure I would suggest Danish Oil for this issue Jaycee is having- but then again I have no experience with decals so who knows.

[jaycee]

I had wiped the coco' with lighter fluid and varnished twice prior to using the Acetone.

I used the Acetone on the headstock and side of the fretboard, it took 50ml, which is 2 fl. oz and rubbed in the shellac, which was dry within minutes. Will varnish over the Shellac after 24 hours, so far so good.

The lighter fluid worked on the fretboard which has a danish oil finish.

Edited September 16, 2012 by jaycee