Hana Lima 'Ia
http://www.hanalima.com/cgi-bin/yabb2/YaBB.pl
>> Ukulele Hints >> dirty sound boards from ebony bindings
http://www.hanalima.com/cgi-bin/yabb2/YaBB.pl?num=1285016840

Message started by stewpot1 on Sep 20th, 2010 at 11:07am

Title: dirty sound boards from ebony bindings
Post by stewpot1 on Sep 20th, 2010 at 11:07am
Hi All,

I have put ebony bindings around the soundboard and have successfully scraped the binding down without marking the sound board. However when sanding the soundboard down later, the ebony bindings seem to bleed colour into the soundboard.

Does anyone know how to clean the soundboard ?  >:(

Stewpot

Title: Re: dirty sound boards from ebony bindings
Post by Don_Orgeman on Sep 20th, 2010 at 12:32pm
Stewpot:

Usually the best way to clean the soundboard from this problem is to lightly scrape the areas of the soundboard.  If you have a good cabinet scraper and know how to use it that works great.  If you don't have a scraper a single edge razor blade or a utility knife blade held perpendicular to the surface works well.  Practice scraping on a piece of cutoff spruce or scrap pine to test the removal before moving to your uke top.

To prevent this from happening in the future coat the top with FRESH 2 pound cut shellac before cutting the binding channel and be careful to not scrub the ebony into the top as you sand.  Since you may have to go back to some more sanding on the bindings after you scrape to top you may want to shellac the top after scraper cleaning.

Hope this helps.

Don

Title: Re: dirty sound boards from ebony bindings
Post by Beth M on Sep 22nd, 2010 at 5:47am
I am just getting ready to make an ebony rosette for a koa top uke and was worried about this same issue. My question is, would you pore fill the top first in this case, then shellac, then inlay and sand the ebony? I have heard that epoxy doesn't take as well if you put it over shellac,which is why I didnt want to shellac the top too early, but that shellac takes  well to epoxy-filled wood.
Thanks, Beth 

Title: Re: dirty sound boards from ebony bindings
Post by stewpot1 on Sep 22nd, 2010 at 10:44am
Thanks for the tip Don, I'll give it a try.

Rgrds,
   Stewpot

Title: Re: dirty sound boards from ebony bindings
Post by Don_Orgeman on Sep 22nd, 2010 at 12:31pm
Beth:

I have never used epoxy before but am thinking of possibly using it in the future.  I would suggest that you look at Kathy Matsushita's journals on her web page.  She has used exopy sealers on at least one of her projects.  After reading her journal if you still have questions, send her an email.  She is always very helpful and will answer email questions.  She also monitors these postings (KMatsu) and may answer your posting here directly.

The idea is to get a sealer on the spruce top to keep the dark materials from sanding from being scrubbed into the pores of the soft top.  I dont know if you would have that problem with harder koa.  You might want to try a test board of koa and ebony glued together and scrub the heck out of the ebony onto the koa to see what happens.  I suspect that you will find that a good air blast will blow the black ebony powder off the koa with no staining.  If you need a barrier I don't know why epoxy wouldn't work just as well as shellac.

Don

Title: Re: dirty sound boards from ebony bindings
Post by Beth M on Sep 22nd, 2010 at 8:20pm
Thanks Don,
I'll try a "test piece" and let you know!  Beth

Title: Re: dirty sound boards from ebony bindings
Post by Don_Orgeman on Sep 23rd, 2010 at 2:59pm
Beth:

It looks like epoxy filler is used on the sides, back, and neck but not on a spruce top.  I suspect you would use it on a koa top.  It also looks like shellac is good under the epoxy.

Look at Kathy's size 5 guitar build journal for details.

Don

Title: Re: dirty sound boards from ebony bindings
Post by konacat on Sep 27th, 2010 at 7:50am
Argh!  I hate spammers.


The general consensus on the Official Luthiers Forum is that shellac is great on top of epoxy. The shellac is a good bonding agent between the epoxy and your finish. However, epoxy doesn’t bind well to shellac.

Don, interesting thought with the epoxy on a koa sound board. I guess this would apply to any hardwood top.

I have been using Zpoxy finishing epoxy as a pore filler (be aware there are 3 types of Zpoxy). The 1-1 mixing ratio really makes it easy to work with. Make sure your wood is clean and dry. Mix a small amount of Zpoxy (a little goes a long way). Work it into the pores at 45 degree angles with a squeegee or old credit card. Push it down into the pores. Squeegee off the excess epoxy and let dry. Then sand just down to the wood but without removing the zpoxy in the filled pores. Wipe clean. Make another batch of Zpoxy and mix 50/50 with denatured alcohol. This is used as a wash coat to even the color and make the wood really pop (makes grain and figure look great). You squeegee this as thin as you can cover the desired area. Try to keep the work area smooth. Once dry, you sand any numbs to make the surface level. You can then add your finish directly or shoot/pad/brush shellac as a binder between the epoxy and finish.

Philip

Title: Re: dirty sound boards from ebony bindings
Post by Beth M on Sep 29th, 2010 at 6:54pm
Thanks Philip!

Title: Re: dirty sound boards from ebony bindings
Post by sailor tim on Feb 5th, 2011 at 7:15pm
use 2 lb cut of high quality shellac, take a 4 inch square of cotton cloth, t shirt is great, fold it in quarter and applly shellac in one direction and change to a new quarter for each new piece of inlay.  let dry and apply 2-3 more coats, you will notice your pad will be clean when you have enogh shellac on.  dont sand through.  Also if you are good with a scraper you should not sand after scraping.  The whole idea of using a scrapper is they shear the grain and leave a much cleaner surface than sandpaper which tears the grain.

Hana Lima 'Ia » Powered by YaBB 2.4!
YaBB © 2000-2009. All Rights Reserved.