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So… I was listening to a recent podcast… can’t remember which one… and the builder was a dye maker.,,,
He said a certain solvent won’t cause rosewood to bleed onto your purfling and spruce… but others will…
Was it naphtha???


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I think I have heard using acetone for that?

Found it
The safer solvent is naphtha.
The guy said acetone actually makes it bleed worse

It’s the most recent luthier on luthier


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Alcohol can make it bleed too.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Yes… I found that out a few builds ago.. soooooooooo frustrating ha


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Hydrogen dioxide is another solvent that won't cause rosewood to bleed, but it may raise the grain of the wood.
What are you using the solvent for?

I thought that was the point though, to bleed it out. That way when you go to use it, it's bled out.

The luthier being interviewed in the segment in question, by the way, is Jeff Jewitt, proprietor of Homestead Finishing Products. While he probably makes fine guitars, most of us know of him because of his expertise in finishing. He's written several Taunton Press (i.e., Fine Woodworking) books on the subject.

And if you don't already, follow him on Instagram. He's building beautiful stuff and starting to share tips and technique in videos.

https://www.instagram.com/jeffjewitt/

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Just to wipe down… check for glue / imperfections / scratches and such


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As previously suggested Naptha. A blacklight flash light is perfect for finding glue. They are sold to find cat piss.

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https://www.youtube.com/watch?v=N2boczY_myc

"Oh God, I hope it's urine."

H2O Is what many woodworkers use (myself included) to check for glue and sanding scratches. Aside from being virtually free and readily available it raises the grain slightly and allows for final "nib" sanding. The "universal solvent" is weak enough to not move oils around.
For cleaning surfaces that are finished I like to use VM&P naphtha, because it is a little less smelly than regular naphtha

So with all this being said. When doing shellac/french polish for a finish what's a good technique to keep it from bleeding onto your binding?

My last build was rosewood with sycamore binding and I just taped everything up. If there's an easier way though I'm up for learning it. I had thought about just using black binding like richlite or just black plastic so it wouldn't show up as much.

Lord knows I'm no expert, but I have a suggestion.

First off, use a thin cut (1 lb.) for what I will suggest. Don't use any oil at this point. Run a modestly wet pad with a "disposable" cover along the length of the binding, trying really hard to keep the rosewood part of the pad over the rosewood and the sycamore part of the pad over the sycamore. Go back and do this a few times, on both the part of the back and the part of the sides that are adjacent to the binding. The 1 lb. cut will flash off pretty fast, so that you can go over it again pretty soon. The goal is to get the transition area sealed so that it stops picking up color. When the pad cover gets a noticeable amount of color, ditch it and get a new pad cover. Keep this going until the pad cover stops picking up color.

This is easier if you have used a non-traditional pore filler, like epoxy, and sanded back to wood. If you try to do a traditional pumice pore fill, it gets harder, because the process of rubbing the pumice into the rosewood tends to wipe out the seal coat.

Using a 1 lb. cut has been a real important change for me. It dries much faster, which makes it easier to go back over areas without causing problems.

Pretty much the same as Don, but I use squares of muslin instead of a pad with cover. Cut to a little over 1" square, pull out any loose fibers from the edges, and fold it over twice. After both sides are contaminated with color, flip the second fold over the other way and you have two more fresh surfaces which are already wet with shellac Highly efficient.

If only the binding or the side wood bleeds, then just gradually move toward it as you wipe, so the other woods have a continuous supply of fresh cloth.

If you have a light colored purfling line between two bleeder woods, or a bleeder purfling line between two light colored woods, then you have to be more careful. Don't put too much shellac on the cloth, and use your index finger knuckle to maintain a constant distance from the edge, similar to how a binding router works.

If I am french polishing I use clean rags and wipe down the bindings with shellac, careful to not wipe from dark wood to binding. I might do it a few times. If I am filling with epoxy. I first wipe down the binding with epoxy and wait an hour or so and do the rest (with fresh epoxy)

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Another possibility is to "mist- on" several light coats of Bullseye spray can shellac on the edges with the bindings, allowing it to dry between coats. Make the coats light enough ("dry coats") so the color doesn't run. If some color does run use a razor blade to scrape it off where it doesn't belong. After applying several coats in this fashion you should have things sealed up enough to proceed with French polishing.

For disposable fad covers I have used paper towels if you go that route.

First time I ran into this problem was on my first guitar when I did a cocobolo rosette, talk about bleeding color! That was a pain. Now I do the same thing Clay does with Bullseye. Last guitar I finished has curly maple bindings on rosewood B/S; no problems.

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Steve Smith
"Music is what feelings sound like"

At this stage now. Can I just use Zinzer shellac with the pad method? Thx, Roy

I would thin it to a 1 lb. cut first. Paradoxically, you can build the film thickness faster with lots of thin coats. They dry faster in between applications.

If you are just coating rosewood bindings you can use Q-tips to apply the shellac, and change them as they pick up color. Keep a razor blade handy to scrape off any color that coats places it shouldn't be..