Gold Brass

[bigbob]

What is red rot???What is a darktone as opposed to a bright tone and what are overtones?? thanks..............................................................bigbob http://www.rgisculptures.com" target="_blank

[iiipopes]

While you're looking it up on google, "red rot" is the disintegration of the zinc out of the brass alloy, leaving behind "swiss cheese" copper that is spongy and porous. There is no cure. The affected parts have to be cut out and replaced. Usually the cause is acidic environment, but not always.

[iiipopes]

bloke - indeed. The point being that either extreme, acid or alkaline, can leech the zinc out of the brass, because it is an electrolytic process, not a corrosive process.

[Roger Lewis]

From my conversations with Gerhard Meinl, the traditional yellow brass, as stated earlier is usually about 70% copper 30% zinc. Gold brass increases the copper content to roughly (as stated earlier) 80% copper and 20% zinc. Red brass, such as on the bells of the old Conn 88H trombones and again as stated earlier, is roughly 90% copper and 10% zinc.

I have noticed that the Chinese instruments tend to come through with what appears to be a more 60% copper and 40% zinc alloy.

Just my $0.02.

Roger

[bigbob]

Thank You all so much you have been very helpful and informative...bigbob http://www.rgisculptures.com" target="_blank

[imperialbari]

Isn’t 60/40 with 1% tin Admiralty brass? And weren’t York using exactly using Admiralty brass for at least their tubas?

One problem with large bore instruments is clarity in very low dynamics. Is it possible that part of the York magic comes from a richer overtone pattern exactly in the lower dynamics?

The bug has worked with York patents, but found nothing on the alloys.

Klaus

[imperialbari]

The copper/zinc ratio is important, but is not the only important factor. The coin metal (Münz) may have the same ratio of the main ingredients as Admiralty brass, but still be very different and undesirable for musical purposes exactly because of deviations in the small-amount ingredients.

70/30 is military standard cartridge (powder container) brass in several countries on both sides of the pond. Nearly 30 years ago the production manager of Boosey & Hawkes at a clinic in Denmark told, that the absolutely worst national standard of cartridge metal by metallurgical points of view was the one of the USA. Which in turn was the reason for American trumpets and trombones excelling over their European equivalents.

Before international logistics improved, cartridge metal was the brass alloy available at reasonable costs. Anything else would be very expensive,

bloke’s observations on the red colour of the helicon in the Oberloh photo really caught my attention. The low brass must have been more expensive, but the extra costs have been justifiable because the simpler plating process could be made in-house, thereby cutting out the shipping costs forth and back to the plating company.

Klaus

[imperialbari]

Now we know how bloke gets his tubing for spares and repairs: he sts up a trap!

I have been very close to Chinese culture and business practices. I won’t comment on this myself, only quote a very important US periodical of my youth, MAD: The main challenge in managing a Chinese restaurant is knowing the food ingredients from the garbage.

As for Chines metals of dubious heritage: In nJune this year a molar broke and went beyond further repair. I had some Danish made gold based ceramic crowns already, but a cheaper alternative has entered the market and shall be mentioned by the dentist: Chinese crowns can be had at a much lower price justifying the longer wait. The problem is that the gold alloys used by the Chinese cannot be controlled even if they are backed by a guarantee from a Danish laboratory. I want my crowns to last my time out, so I chose the locally made crown. Somewhere I have the formula for the gold alloy- Interestingly it also holds expensive ingredients like platinum. Pure gold would not like heat of the ceramic oven and it would not be hard enough to withstand the force of a human bite.

Klaus

[Daniel C. Oberloh]

re: the fact that your King helicon is made of "gold brass"...

Do you think it's that old speciality brass that many refer to as "low brass" (ie: low zinc)? I'm pretty sure that American manufacturers early in the 20th Century made instruments out of "low brass" that were specifically targeted for factory silver plating...The silver bonds better to "low brass" than it does to most run-of-the-mill "yellow brass" formulations, and without the "copper strike" step being necessary.

I don't think this is the case. During my time in the silver-smiths trade, we used copper for many of the products we made that were then silver plated, such as punch bowls, ladles, and other deep drawn and/or hammered vessels. Copper is malleable and relatively simpler to hand-work then brass. My past experience in addition to the understanding of the methods in large brass instrument production (used in 1905) leads me to think that the materials chosen had more to do with the physical production of the parts and the ease of finishing then the enhancement of plating bond. The old silver plating methods are pretty damn good and as long as the sub-straight of the material is properly cleaned and prepared, it don't matter if its copper, bronze, brass, nickel-silver (any copper alloy), its gonna plate just fine.

Daniel C. Oberloh
Oberloh Woodwind and Brass Works
http://www.oberloh.com" target="_blank"

[TubaSailor]

English handbells are made of a very stiff bronze alloy. (I've played in several very good, auditioned groups for more than 20 years, and have had to maintain several sets for many of those years). The analogy to a tuba really doesn't work unless you want to make the tuba a percussion instrument. One thing we seem to lose sight of is that the resonance of the tuba is really more due to the shape of the air column inside, and only partially to the material shaping that column. - Take a look at gooddigs' plastic tubas or the Martin fiberglass horns - They seem to work!

Back to the gold brass issue: I've had some of each, and I can only conclude that the differences between individual horns are bigger than the difference due to the material. I like the timbre of the gold brass 181 I have now, and many musically discerning people have commented on how mellow it sounds, but I can't ascribe that to the gold brass - if I change mouthpieces I can make it as strident and bright as any yellow brass horn I've ever played.

[imperialbari]

I have no gold brass tubas, only a gold plated one. But from my other brasses my experience is that those made out of thin sheet gold brass tend to be very alive. And a potential danger from yellow brass corroding has been overlooked in this debate even if the problem was widely publicized already around 1950:

[Roger Lewis]

The brass on the Chinese imports seems, to me, to be lighter in color than the yellow brass from Europe - it appears with a little more "white" in it. Also when working out a bell crease, there will usually be a lot more scarring visible and I was told this comes as a by-product of a higher zinc content.

As to gold brass horns playing stiff, it takes a gold brass horn a lot longer to "break in" than a yellow brass one. A yellow brass horn will break-in and relax in about 2 to 3 months, where a gold brass horn can take as much as two years before it settles. I don't know why this is, but I was told this by an extremely reliable source. My JBL Classic F tuba is gold brass and it is only now feeling a tad more stable than when I received it and after the repairs needed from the view in my avatar.

Just my $0.02.

Roger

[oedipoes]

I have a simple question that may shed some light on the subject. What type of brass do they use for the bells that are used in bell choirs? I would think that they would have figured out long ago the most resonant and musical alloy for this application and it might hold true for tubas?

bells are made out of a bronze alloy that allows for casting, I can imagine that being very much different from the alloys used for hammering (forging?) a tuba bell.
Don't know about the real tiny bells though...

[MartyNeilan]

As to gold brass horns playing stiff, it takes a gold brass horn a lot longer to "break in" than a yellow brass one. A yellow brass horn will break-in and relax in about 2 to 3 months, where a gold brass horn can take as much as two years before it settles.

I know that this is a comment attributed to certain tuba professor (I've never personally heard him say it). Maybe it would help to leave a tuba out in the snow, too. You know, to freeze those molecules.

Are we talking about yellow snow or gold snow?

[TubaTodd]

.... Maybe it would help to leave a tuba out in the snow, too. You know, to freeze those molecules.

Slightly related...

The year after I graduated college I was working @ Hickey's music. My professor's 6/4 York came into the repair shop looking a little dirty and had some leaves on/in it. Yep...he played tuba in the woods and left it there overnight (that was the story I heard). I don't recall if he was out in the snow.

[Kevin Hendrick]

I know that this is a comment attributed to certain tuba professor (I've never personally heard him say it). Maybe it would help to leave a tuba out in the snow, too. You know, to freeze those molecules.

Are we talking about yellow snow or gold snow?

"Watch out where the huskies go and don't you eat that yellow snow..."

Ugh! Snow! Yuck!

Exactly -- "good thing we didn't step in it ..."

[imperialbari]

bloke and others have said that part of the breaking-in process is about valve casing corroding on the inside making the valve systems tighter.

I don’t remember seeing any brasses having gold brass valve casings. On the contrary some Markneukirchen-instruments, and possibly also instruments out of other places, have nickel silver valve casings.

Denis Wick says that breaking-in is about the inner surface of the tubing getting corroded.

Isn’t it so that red brasses corrode more slowly than yellow brasses?

Klaus

[Mcordon1]

"Watch out where the huskies go and don't you eat that yellow snow..."

Ugh! Snow! Yuck!

ZAPPA!

[Wyvern]

So, as the inner surface of the tubing oxidizes - how does that effect the tone? Does a tuba have to be played to be 'breaked in', or will it do so if just left unused?

I have also heard it is about the stresses created during the build relaxing.