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Alfieri

Pernambuco wood treatment

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This is a picture of a chinrest and violin tailpiece with no color treatment

paubrasil.png

, but I would make it like this one color.

pernambucowood.png

I heard that treatment with nitric acid , can make the pernambuco wood very red, but I´m not sure.

Can anyone help?

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I heard that treatment with nitric acid , can make the pernambuco wood very red, but I´m not sure.

Can anyone help?

The limited experience I have with nitric acid on pernambuco has made the wood darker, but I would not call it redder. Different pieces of wood might react differently. You could try little spots on the undersides of the tailpiece and chinrest to see how your wood will react.

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There is no way to control how the acid reacts with the pernambuco. It can go from being a slightly darker orange to very dark red approaching brown. I have been told that multiple treatments will continue to change the color to various shades of red. I would suggest testing it out on a piece of pernambuco from which the chin rest was made and if you don't like how it reacts with the initial treatment, try treating it again. You have to give it time to settle in after treatment, though. I have treated bows that came out relatively dark and a week later were somewhat lighter.

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I'll be very interested to see the advice that you get on this one. First off you've probably got some type of finish on both pieces that you need to consider before you treat anything. Will the acid ruin the finish or go through it? Then you MUST consider the danger involved both to your lungs and skin in dealing with acid. Then you must decide how you would apply it as direct application is not only dangerous but streaky, thereby ruining what you have.

Ammonia will turn perambuco bright fire engine red which turns to brown after exposure to sun light once again unpredictable. If you take off the finish you would need to re apply something or you will have a colored cheek. I'm not a big fan of pernambuco chin rests in the first place.

Oh and you definmately would need to remove the hardware before doing anything. I did some minor acid coloring with diluted stuff on my bench and you should have seen what it did to the files on the wall. Hint (think lungs). You are actually lucky that the fittings are brown in the first place, most pernambuco is orange which doesn't work very well with most varnish colors IMO. You've already gotten some good advice-- it's an unpredictable and unpleasant process at best. If someone doesn't think so-- pay them to do it. ;)

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I use pernambuco only for the tongues of my lions heads.

I get a reddish color by first putting it into a potash (or ashes from the stove) water solution, then put it into alum solution to (in theory) fix the color.

This should not be dangerous for anybodys health. Not even the lions.

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I use pernambuco only for the tongues of my lions heads.

I get a reddish color by first putting it into a potash (or ashes from the stove) water solution, then put it into alum solution to (in theory) fix the color.

This should not be dangerous for anybodys health. Not even the lions.

I've got pernambuco and plenty of ashes in the fireplace so I tried your method today. It really did turn it red. Might be too red for what Alfieri is after though. I'm pretty sure he wants that rich red brown like the bow head. I'll put the piece that I stained with the potash in the sun as soon as we have any, but in Oregon that could be about July. :(

That might brown it up. Don't know if he'd want to drop his tailpiece in a water solution or if the potash solution would penetrate or screw up the finish.

Didn't have any alum to fix the color. Would ammonia fuming do the same thing? That's how you fix it after the nitric coloring.

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I've got pernambuco and plenty of ashes in the fireplace so I tried your method today. It really did turn it red. Might be too red for what Alfieri is after though. I'm pretty sure he wants that rich red brown like the bow head. I'll put the piece that I stained with the potash in the sun as soon as we have any, but in Oregon that could be about July. :(

That might brown it up. Don't know if he'd want to drop his tailpiece in a water solution or if the potash solution would penetrate or screw up the finish.

Didn't have any alum to fix the color. Would ammonia fuming do the same thing? That's how you fix it after the nitric coloring.

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My experience with nitric acid on pernambuco is that it turns it brown, but some sticks have a reddish tinge to them. Every stick seems to be different in the way it reacts. Sticks I have fumed with ammonia have turned a liver red that eventually goes brown. I haven't tried potassium hydroxide (potash, lye) yet.

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Pernambuco's bad enough already. I'm not so sure about using that wood in any form for chin rests. The neck there is already a sensitive area from overuse. I sure wouldn't care to put my chin on that if you treat it with acid or strong base, unless you very thoroughly neutralize it, and that probably means soaking it. I don't see why you can't just let wood be wood. If you don't like it, I suppose you could use a wood stain, or use a different wood.

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Heres a result of one of my colour tests all with pernambuco from the same log.The first two are 10mm thick.

There is NaOH (caustic soda) before and 2years later+ coat of shellac

HNO3 before and 2 years later + coat of shellac

And untreated before and after ,with a coat of shellac down the outside thirds.

Each spent 6 months on a window sill in direct sunlight.The next 18 months they were on a shelf under just room light.

I have to conclude i prefer the untreated .The acid treated one appears to have slightly affected the untreated side.

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I'm pretty sure he wants that rich red brown like the bow head.

That´s right.

I don´t care about the chin rest.

Actually, my goal is the tailpiece, because the sound improvement, ( if really there is a sound improvement with a pernambuco tailpiece, I´m not sure ).

This fitting set I buyed from a local luthier, here in Brazil, but I didn´t know that pernambuco can be brown, now I know.

I thinked that turning it reddish, it would appear more like a " real pernambuco ".

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Pernambuco's bad enough already. I'm not so sure about using that wood in any form for chin rests. The neck there is already a sensitive area from overuse. I sure wouldn't care to put my chin on that if you treat it with acid or strong base, unless you very thoroughly neutralize it, and that probably means soaking it. I don't see why you can't just let wood be wood. If you don't like it, I suppose you could use a wood stain, or use a different wood.

La Folia,

For me, as a player, the concerns raised in your post made a lot of sense. Irritation to the skin is always a concern with a chin rest. No sense in enhancing the possibility of irritation by using a wood that tends to provoke irritation and then, on top of it, treating it with irritating chemicals.

Another concern would be weight. I understand that some pernambuco will sink in water. If the wood is that heavy, that's a lot of weight in a large chinrest like the guarneri pictured here. Whether it sinks in water or not, pernambuco must weigh considerably more than boxwood.

Still another concern would be that some pernambucos can be quite porous on their surface. Those little pits can be a place for hair follicles to get caught, making those chinrests uncomfortable for males. I have a walnut chinrest that has a rather porous surface, and a few hair stubbles on the underside of my chin would get caught in those pits and pull when moving the fiddle away from the neck. Now after some years of use those pits have filled with oil, dirt, and that's no longer a problem. But initially it was.

I would think that the issues of weight and possible skin irritation would also make pernambuco a questionable choice for a tailpiece.

Anyway, I know this thread is not really about whether pernambuco makes a good chinrest material or not, but I doubt that pernambuco is good for chinrests.

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I've got pernambuco and plenty of ashes in the fireplace so I tried your method today. It really did turn it red. Might be too red for what Alfieri is after though.

With time and light, it will go to brown, more or less.

Didn't have any alum to fix the color. Would ammonia fuming do the same thing? That's how you fix it after the nitric coloring.

I have no experience with ammonia and pernambuco. I'd think what the ammonia after the acid does, is neutralize the acid.

The idea with potash + alum is that, (theoretically,) it will form a lake combined with the color substance in the pernambuco.

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I dont know about anyone else but ive always had a slight ezcema problem but never had any problems with pernambuco whatsoever. The main concern with pernambuco and other tropical woods is usual when working it and breathing the dust. The dust doesnt bother me either. Everyone is different and i find myself far more sensitive to working spruce,pine etc... ,i assume its rosin in it as the rosin on bows irritates me slightly as well. Many rosewoods are quite irritating to work .The pores in pernambuco are not usually large enough to trap stubble on your chin,especially compared to walnut,mahagany etc..It is rather heavy and i wouldnt personally use it as a chinrest.

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That´s right.

I don´t care about the chin rest.

Actually, my goal is the tailpiece, because the sound improvement, ( if really there is a sound improvement with a pernambuco tailpiece, I´m not sure ).

This fitting set I buyed from a local luthier, here in Brazil, but I didn´t know that pernambuco can be brown, now I know.

I thinked that turning it reddish, it would appear more like a " real pernambuco ".

I'm working on an order right now for someone who wants a browner colored pernambuco set. I don't want to use nitric, and the sun won't be out for some time, so ammonia won't do the trick. I have a friend who has a light box and I may experiment with that. Otherwise it's got to be stain misted on with an air brush and buffed in before the finish. You might want to find out what type of finish is put on the wood of your tailpiece. I assume it's made by Arcos Brasil.

Pernambuco's natural color is all over the place from very orange yellow to reddish to chocolate, and some oxidizes and darkens more than others. Yours is a pale brown which may redden nicely after the ammonia and sunlight. If it has any coating on it-- I guess it depends on the type of finish. I must admit I'm intrigued with the potash staining. Not sure that I want to submerge a polished tailpiece and raise the grain though, but I think I will try it on one.

As I said I don't think it's a great chinrest wood. It's more skin related than weight (there are lots of ebony rests out in violin land).

Bob, there were quite a few bow makers at Oberlin who took many years of working pern. to develop a bad reaction. For me it was strange. The dust wasn't a problem, I was used to that from turning it, but I got respiratory problems in planing it all day. :blink: That was very evident but a mystery to me.

I'm going to post a photo of the pieces I treated with potash yesterday. They became less bright red over night. Interesting. This is what most of my pernambuco looks like without staining, It will darken some.

post-3813-0-04280900-1295122174_thumb.jpg

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Speaking as a player and maybe somewhat naively, I'm surprised that players would worry about the exact shading of a chinrest, because a chinrest, other than ebony and other very dark woods, will quickly change color because of staining from sweat and skin oils.

To make a chinrest impervious to such staining changes, it would have to have a pretty bullet-proof varnish finish, a finish that repels moisture and oils. If a chinrest has such a finish, it becomes rather uncomfortable, rather slimy feeling, like plastic feels, because moisture and oils aren't absorbed into the chinrest.

For me, a chinrest, like the neck of the fiddle, has to be finished so that it will absorb some moisture and skin oils, and not leave them pooling on the surface. That means woods with minimally treated finishes.

I prefer, actually, wood chinrests with natural, untreated finishes, because then I can take sandpaper and adjust the shape of the cup to maximize comfort. A very slight sanding of a chinrest cup, maybe a sliver of a mm here and there, can make a big difference in comfort. If you're sanding on an untreated finish, then there's no real change in overall appearance. If you're sanding on different parts of a highly colored and/or polished finish, then the results may look very mottled.

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No, it wasn´t made by Arcos Brasil, it was made by a local luthier.

Hummmm, I will try ammonia and sunlight.

Ammonia may soften the finsh at first if it is shellack, so easy handling on it. You know I mean fuming, right? I hope it works for you. Ask the luthier what he finished it with first. If it is lacquer it might not permeate the finish. If it does work it will be ugly red at first and then brown up, but as we all said it's unpredictable, so be advised. It would be much better if yopu had a piece to test. Did you notice a sound quality change when you switched BTW?

Here are my photos. as you can see ambient like makes a big difference The one unfinished tail is just that, not even polished. It sat around the shop for a year. The small one is a commercial German tail somebody gave me- probably not treated but covered with some industrial finish. The pieces of wood are the ones I dunked yesterday. They darkenned up over night. I may try the light box on them when I get the chance. I wonder if just wetting them would do the trick. I'm not sure dunking a tailpiece for very long is a good methodology. When you sanded the raised grain you would probably go through the darkenning.

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Did you notice a sound quality change when you switched BTW?

Not so much, I tried a maple tailpiece, a ebony, a caviuna wood, but maybe the maple one give me a upgrade sound.

The pieces of wood are the ones I dunked yesterday.

Dunked in what ?

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