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So,

I've bult a nice mahogany neck from some nice old mahogany, laminated with two ebony strips lrunning the length of the neck. I've shaped it 98% using planes, chisels, scrapers, and it looks pretty good. It's the last yard, and I think the last touches need to be sanded. However, I know that sandpaper on this ebony will create some pretty nast dust that will seep into the pores of the mahogany, that remains a bit rough. How do I do the final sanding, prior to attaching to the body, while keeping the ebony dust from bleeding into the mahogany (and everything else)

Thanks!

Scraper.

Before I knew how to use a scraper, I would seal the pores of the wood with rattle-can shellac and then sand, using compressed air to blow off the ebony dust. I really didn't get any problems until I went above 220 grit, even on maple - it was the really fine dust that was a killer. You'll sand the shellac off the mahogany, but leave it in the pores where the dust will accumulate.

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The member formerly known as erikbojerik....

did you try blowing out with compressed air?

+1 on compressed air. You'd be amazed what 150PSI can take off.

On things where the air isn't enough (VERY rare), you can scrape very lightly with a razor blade to just take off the smudges without affecting the finish on the part.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Frequent blasts of compressed air (if you don't have a compressor, canned air works good too) and what you can't get with air you can usually get with 0000 steel wool. I always buff the raw wood before finishing with steel wool in addition to cleaning the pores it also helps find sanding scratches you missed.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

I hate "blowing the dust around off one piece of work onto another. Try a vacuum with a brush. Works GREAT!

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God, Family, Carreer

As far as the ebony dust thing goes, it's just a pain. I've posted about this myself in the past. Scraping is always preferential to sanding where possible... save the sandpaper for last resort stuff. I ended up cleaning the ebony dust off of my maple bindings on my first build with a razor blade used as a scraper (after I'd finished the fretboard).

And regarding dust management in general, I second the 'vacuum' suggestion (as opposed to blowing). Perhaps a blast of compressed air after the majority of the dust has been vac'd up if necessary I spose.

I've become much more conscientious about dust lately, and have successfully coached myself to stop 'blowing' on anything (I keep the vacuum nozzle nearby with a remote switch within arms reach). Since doing this, I've cut way down on... the layers of dust around the shop, the amount of coughing I find myself doing after a long session in the shop, and the brown-boogers are history!....

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Jim Hansen

Thanks All. Good advice - will do.

The dust shouldn't be a problem if you don't sand above 220 grit and you shouldn't sand above 220 grit before finishing. Usually just blowing it off and wiping well with naptha will get rid of it. I've never had a problem. It will however be a problem if you sand above 220 grit. Just a note, I would not use steel wool if you are planning on using a waterborne finish.

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Randy Muth
RS Muth Guitars Website
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If you haven't sealed the pores, compressed air can just force the ebony dust deeper into the wood, making it more difficult to remove. The vacuum suggestion is a good one.

Naptha can cause oily woods to bleed into adjacent woods (ebony, padauk or rosewood next to maple for instance).

If you're going with a Tru Oil finish, you do want to sand down to about 1000 grit.

This neck is maple, walnut, ebony and padauk under Tru Oil.

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The member formerly known as erikbojerik....

I have never ever had color bleed from wood using naptha. Alcohol and other solvents will, but naptha won't. VM&P Naptha is a simply a low boiling point fraction of hydrocarbons. These hydrocarbons have very little solvency power and are very non-polar. What that means is that it can develop a good electostatic attraction for dust. This is why it works so well for this purpose. Sometimes it may appear that the color bled, but that is just incomplete removal of the dust. I you don't believe me, take some cocobolo dust or any other wood that you want to try and put it in a small cup with naptha. The solution will be clear once the dust settles. Of course it will spread the dust around, so you should vacuum or blow off most of the dust before using naptha to pick up the residue.

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Randy Muth
RS Muth Guitars Website
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You had me at 'solvency power'. It pleases me greatly every time the chemist in you comes out, I always learn something neat!

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Bob, How powerful a solvent is depends on what you're dissolving. Like dissolves like, so non-polar solvents dissolve non-polar solutes and polar solvents dissolve polar solutes. More clearly, a polar solvent like water will dissolve polar substances such as salt. Now, someone observant might note that oils are fairly non-polar and could be dissolved by a non-polar solvent such as VM&P naptha (hydrocarbons), but naptha is so non-polar that it tends to be a poor solvent for much of anything. Most importantly, dyes tend to be very polar, thus watch out wiping your wood with alcohol.

I also have to question the need to sand to 1000 grit before using Tru-Oil. It is necessary to sand to fine grits when using a real oil finish that doesn't build. Tru-Oil is really just varnish and it does build. I have used it and did not notice wood scratches underneath it and I am very finicky with my finishes. Conventional wisdom is to not sand too finely in order to give some bite for the finish, except when finishing with real oil.

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Randy Muth
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