best finish for koa

[WoodyMcKenzie]

I started carving a koa mandolin yesterday. The wood is so beautiful that I want to be sure and finish it to show its natural beauty and depth. I don't like the look of lacquer very much. Any suggestions? Also, what to fill it with?

Thanks!

Woody
http://file:///Original%20HD/Desktop%20Folder/koa%20mando/koaback.JPG

[WoodyMcKenzie]

I can never remember how to post an image!

file:///Original%20HD/Desktop%20Folder/koa%20mando/koaback.JPG

[Tom C]

Size must be smaller than 77K

[WoodyMcKenzie]

And I just graduated the back-- it's still a little rough though--http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

Woody


file:///Original%20HD/Desktop%20Folder/koa%20mando/holeykoa.JPG

[Luthier Vandross]

You should see Koa treated with dark paste filler, treated as a mahogany Martin guitar.

Oh my my.. it's geeeeeeeorgeous!

Varnish? I don't recommend you just varnish an instrument, without a great deal of practice.


M

[WoodyMcKenzie]

M--

You are right about varnishing being an involved process that takes a lot of practice. I have varnished several violins now, some with varnish that I have made:


http://mckenziemusic.com/fiddleproject.htm

But the varnish I use on fiddles is really too soft for mandolins. The word "varnish" is a confusing term. There are lots of different kinds of varnish. I was hoping someone who has finished a koa instrument or something made of a similar wood (blackwood or walnut?) might let me know what their experience has been.

I did get to see a stunning looking koa guitar once, but the lacquer finish was just a bit too "plastic" looking or "hard" looking to suit my taste.

Woody

[Luthier Vandross]

Well, generally, sealer (can be laquer sanding sealer, or spit coats of shellac), 2 coats of a good gum varnish, rest, 2 more coats, 6-8 weeks, then polish.

You can get a great sound out of a vintage style lacquer finish too. Less=better.

Koa is my favorite to build with, there are a set of unfinished mandos, lin, ola, and cello at the shop, in (beautiful!) Koa... sounds like a dare.. all to be varnished.. let me see what I can dig up.

Miles

[labraid]

I've worked with a bit with koa (and blackwood, as you mentioned also)... Danish oil first coat, anything you want after that.. I like polymerized tung oil for the following coats, it's hard enough and flexible enough, simple to touch up as well.

-Brian

[Chris Baird]

I am varnishing a walnut /w blackwood binding mando right now. I used a thinned down epoxy to fill the pores. I just smeared it on with a piece of plastic then let it dry. I then carefully sanded it back and had a filled pore that looks open(if you know what I mean). I'll post a pic after I sand the bugs out and shine it up a bit. I also tried pumice with alcohol and a little shellac (a michael lewis tip). It is a much faster process but gives a different look. I preferred the clear pore look.

[Luthier Vandross]

You can substitute many fine grained .. umm.. substances for grain filing, with shellac.

Never add more than the first drops of oil (to the pad) and a pepper shaker works great to add filler... like pumice... or talc, or whatever. The grey plastic pepper shakers, you cut the bottom out, and fill her up, then crazy glue the bottom on... works for a couple instruments.

Talc works well on hardish, wider grained woods.. mostly stuff you guys might never use.. like maybe ash, in an extreme. (makes a nice patina.. say on a telecaster.. err. telecaster-mandolin..) You almost add it til it's become nearer a paste, than a liquid.. it can get sticky.

Pumice throws people for a loop.. why pumice? Because it's sharp, and cuts the standing grains, and that is what fills the wood pores, along with the pumice....

..and no your mandolin won't turn black, but it will make you sound like Don Ho.

http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mandosmiley.gif

Rottenstone: You are going to need some of this, if you care to partake in tradition.

1500, 2400, 3600, 6000, 12,000 grades of micro-mesh: You are going to need these if you want to partake in sanity.

These mandolins all sound pretty, hurry up!

M

[WoodyMcKenzie]

Thanks for all the advice guys!

I am going to have to play around with some different fillers & sealers first.

So far, I have really enjoyed working with this wood-- much better than some of the hard curly maple that has been more troublesome to carve. I bought this set of wood from ebay, but wonder if there are other good sources for koa or other similar woods. Would you consider walnut to be similar?

Woody

[Chris Baird]

I've carved Blackwood which is a relative of Koa and it was much more difficult to carve than walnut. Walnut is great to work with. It has some fine carving properties.

[mandomaniac]

I have had great success using Permalyn on walnut. Use the sealer then multiple hand applied thin coats,sanding back between coats to finally fill the pores. Then build a thin finish with great 'depth' like French polishing. Very durable. I suspect it will do wonders with koa as well....certainly hope so since it is on the docket here!

[Luthier Vandross]

Koa is more like red maple, than walnut.. black walnut can pull out, like rosewoodish.. I like it ok for guitars, not to sure about an F in walnut... hmm.. the thing it has going for it is oil content.. when dry, the oils are not nearly as nasty as rosewood.

I was working on a neck set, and mahogany explosions all day, I meant to get some pics of the unfinished koa mando family at the shop.. I am DUMBY! #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

I did add a pick to the Fern ad, if you want to see a boobooougly picture of how beautiful number one is.. yikes!

You can't use the word K_rap on here? hehe


M

[Chris Baird]

Here are a few pics of that walnut/blackwood mando I'm varnishing. This is right after I brushed on some varnish.

[Chris Baird]

Here is a shot of the blackwood binding.

[Chris Baird]

Here you can see the how the grain looks open but doesn't show on the varnish surface(just the dust).

[Luthier Vandross]

Hey! Handome stuff! Looks almost like koa, in that light.

M

[WoodyMcKenzie]

Chris--

Yes! That is a beautiful piece of work!! Is the walnut eastern black walnut or something else? And what kind of varnish are you using? I am also curious as to why you chose blackwood for binding-- is it just the look you are after?

Woody

[Chris Baird]

I'm not sure what kind of walnut it is. It is wood leftover from my decorative carving days. The white in the middle is some of the sapwood. The varnish is an oil varnish that I bought commercially and added a few things. The blackwood is leftover from another mandolin and I thought it would look nice with the walnut, understated but elegant http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[Luthier Vandross]

It looks very nice, the binding is a very nice touch.

M

[sunburst]

The blackwood is leftover from another mandolin and I thought it would look nice with the walnut, understated but elegant http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif
Mission accomplished!

I too am a fan of clear filler for open grained wood as opposed to dark fillers that flatten the look and make it look to me like formica.

I just finished an instrument of walnut with curly maple bindings. (no pics, it's not a mandolin) The grain was filled with multiple coats of lacquer sanded 'til level. It's a lot of work, but the grain looks deep.