Raw Brass or Lacquer?

[evan]

Acidic sweat comes from what you eat; if you eat primarily acidic food (and the vast majority of Americans do) then your sweat will be acidic and you will get "green hands." Getting away form meat, bread, and dairy, towards fish and vegetables, will not only keep your hands that nice color they started out with but give you a better chance of missing out on many serious illnesses.
MA

Now I'm not trying to start a fight here , and I do agree with your dietary suggestions as being healthy, but I was under the impression that all living organisms internally internally regulate their pH levels very carefully. I've never found any textbook / scientific literature that associates pH with diet.

[Donn]

Acidic sweat comes from what you eat; if you eat primarily acidic food (and the vast majority of Americans do) then your sweat will be acidic and you will get "green hands." Getting away form meat, bread, and dairy, towards fish and vegetables, will not only keep your hands that nice color they started out with but give you a better chance of missing out on many serious illnesses.
MA

Now I'm not trying to start a fight here , and I do agree with your dietary suggestions as being healthy, but I was under the impression that all living organisms internally internally regulate their pH levels very carefully. I've never found any textbook / scientific literature that associates pH with diet.

Good question, and I won't pose as any kind of expert in this matter myself, but my thought on it is that you're right, normal pH is certainly not a passive result of dietary input. Of course, a major part of that regulation of blood chemistry is excretion - kidneys, and (QED) sweat. A meat eater may have a higher incidence of kidney stones, due to uric acid - you can find that in the medical literature, I think. If the medical profession ever wakes up to the problem with silver plated musical instruments, we may see better data on that too.

As a health matter, it does seem to be coming from the alternative world, and it may not really matter on a practical level if the effects are actually due to blood pH, or some other physiological process associated with acidic inputs. And of course it's conveniently tailored to the apparently universal human preference for splitting things into two categories, ideally the good one and the evil one. So take it with a grain of salt (but just one!), it's just something interesting to think about, about the things we eat.

[tubaguy9]

Really, I've heard from a great repairman that laquer doesn't effect the way a horn sounds. Out of many of his experiences, it basically isn't worth keeping the chemicals for it.
So concensus is that finish doesn't matter.
tubaguy"who could offer you the name of that birdie on a PM"9

[Outawind]

An associated humorous story, if I may:

I had the privilege of taking tuba lessons from Neal Tidwell in the early - mid 90s. Neal was formally tubist for the New Orleans Symphony, and when he moved to Pittsburgh, became principal tubist for the River City Brass Band and taught tuba performance at Duquesne University. Neal could usually be found with a 4/4 CC Scherzer on his lap. The horn started life with unlacquered body, lacquered bell, but over time, the bell had "evolved" ("devolved"? ) into a near-unlacquered state. His tuba colleagues in the RCBB invariably had horns that were newer and a danger to one's eyes from the glare of the stage lights reflecting off their shiny finish, so Neal was constantly bombarded with friendly verbal jabs from his many fans wanting to know if he needed help polishing his horn. Neal at first tried to patiently explain his opinions re the potential deleterious effect of a lacquer (or any) finish on a horn's tonality, but when he saw that this was a futile effort, he simply said (with a straight face) that he was saving his $$$ and hoped to be able to buy a new tuba with a bright finish someday.

[tubaguy9]

Rick "suggesting that the sanding and buffing have the effect, not the lacquer" Denney

I'd almost say that I don't think that you should have to use a belt sander on something...except fiberglass horns. Wouldn't a little sand paper, with elbow grease and buffers be the best bet if you wanted to completely redo the finish on a horn?
Also, to emphasize the fact, lacquer is basically just a clear coat. Nothing else. And if the piece isn't clean, the lacquer won't look any good in more than a month.
tubaguy"who is learning about this stuff"9

[Dan Schultz]

Rick "suggesting that the sanding and buffing have the effect, not the lacquer" Denney

I'd almost say that I don't think that you should have to use a belt sander on something...except fiberglass horns. Wouldn't a little sand paper, with elbow grease and buffers be the best bet if you wanted to completely redo the finish on a horn?

About the only way to remove deep scratches is to either sand the brass until the scratch is gone... thus removing material.

Or... heavy copper plate the horn to the depth of the scratch and buff the horn severely. Either way, the horn is not the same as when the operation is started.

[tubaguy9]

Rick "suggesting that the sanding and buffing have the effect, not the lacquer" Denney

I'd almost say that I don't think that you should have to use a belt sander on something...except fiberglass horns. Wouldn't a little sand paper, with elbow grease and buffers be the best bet if you wanted to completely redo the finish on a horn?

About the only way to remove deep scratches is to either sand the brass until the scratch is gone... thus removing material.

Or... heavy copper plate the horn to the depth of the scratch and buff the horn severely. Either way, the horn is not the same as when the operation is started.

Why couldn't you just use some really rough buffing compound for those deep scratches? I know there's a supplier of some ultra rough compound...I know you have to let it dry a bit on the wheel, but on a horn that bad, I bet both of us could find something to do in that time.
tubaguy"who hasn't seen a belt sander in the repar lab"9

[The Big Ben]

Why couldn't you just use some really rough buffing compound for those deep scratches? I know there's a supplier of some ultra rough compound...I know you have to let it dry a bit on the wheel, but on a horn that bad, I bet both of us could find something to do in that time.
tubaguy"who hasn't seen a belt sander in the repar lab"9

Sandpaper or compound- it's all abrasive. Compound may be a little more subtle than sandpaper but metal is removed. Not much would be removed to remove small scratches while more would be removed to make larger scratches disappear or look less noticeable.

I'm guessing that multiple coats of lacquer or epoxy could be applied with wet sanding in between? Sounds like a lot of effort, though. Probably really change the sound, too.

[windshieldbug]

I hear that body putty works just fine, too

[Dan Schultz]

I hear that body putty works just fine, too

Want to get the lacquer off your horn w/o sanding??? Let me tell you a story....

Years ago played summer musicials each year in Louisville in an outdoor amphitheater.... To combat the mosquitoes we would all slather ourselves with spray on, deep woods off bug spray. I noticed where my right arm touched the bell the lacquer turned from clear to crusty and honey comb looking... My thumb nail was then all that was required to literally flake the lacquer right off the bell....

Was it the bug spray? Or the combination of bug spray and my sweat? Not sure, but the lacquer came off without any effort at all....

RC

I had a similar experience with "Off" bug spray. I was wearing a load of those cheap Mardi Gras beads once when I applied some of that stuff to my neck. "Off" literally dissolved the finish from those beads... creating one heck of a sticky mess. The propellant is listed as 'TCC'. From what I can gather, TCC is a combination of propane and isobutane.... petroleum products that probably capable of dissolving lacquer.

[sailn2ba]

My guess is that those hydrocarbons wouldn't dissolve lacquer, but they would diffuse through it and collect between the lacquer and the brass. Any differences in expansion (like temperature swings) would then result in flaking because the mechanical bond would be compromised.

[Rick Denney]

Why couldn't you just use some really rough buffing compound for those deep scratches?

You aren't removing the scratch. You are removing the brass on either side of the scratch, so that it's level with the bottom of the scratch. That makes the scratch disappear. It doesn't matter whether you use sandpaper or tripoli--the result is the same.

In fact, I'll bet that 1000-grit sandpaper removes less brass in a given amount of time than does tripoli on a 2-HP buffing wheel.

Oberloh plates the instrument in copper to fill up the scratches, and then sands away the copper down to the original level of the brass. That's fine for scratches. Removing dents leaves ripples, though. Dents stretch the brass, and that leaves extra material that has to be put somewhere. Good techs can spread it around to minimize visible effects, but to get that factory-fresh smoothness will require sanding or buffing the surface down to a smooth level. Plating with copper first minimizes the amount of brass removed, but the sure result is that the instrument will no longer be a uniform thickness. Some hand-hammered instruments aren't uniform to start with, and any process that requires filling and removing material will make it less so.

One final thought: All instruments are scratched. The question is how big are the scratches. If the scratches are small enough to be microscopic, the instrument will look polished. Even optical glass is figured with an abrasive, with the objective being to reduces the depth of the scratches to something much less than the wavelength of light. Fine sandpaper makes finer scratches than coarse buffing compound. Using fine buffing compound to remove enough material to hide a deep scratch might take a while. Techs and instrument makers use sandpaper to work faster.

Rick "who'd rather see the ripples" Denney

[Daniel C. Oberloh]

It doesn't matter whether you use sandpaper or tripoli--the result is the same.

In fact, I'll bet that 1000-grit sandpaper removes less brass in a given amount of time than does tripoli on a 2-HP buffing wheel.

Huh? hmm, I think I might have to take you up on that bet Rick.

Same surface feet per minute? I think 1000 grit will chew things up faster then tripoli but there are a lot of variables.

During my time working in the plating biz, the process where tripoli is used was referred to by metal finishers as polishing or ''cutting''. When we are buffing, we are at the stage where very fine, visible scuffs were being addressed and the stage where the luster (or glow) is brought out is ''color buffing''. Color buffing is where rouge compound is applied and has a burnishing effect.

When properly sanded, you are removing the high point of the scratch only. When buffing you are removing metal from high and low points of the scratch; the high points are taken down faster and eventually you catch up to the low points that are taken down more slowly. Buffing alone can and does remove more metal then the combination of sanding and then buffing. Proper sanding followed with careful polishing/buffing will yield far superior results in much less time while minimizing loss of material. I will make a quick pass with 180 or 220 grit and the use progressively finer grit. This process will even things out quickly and allow for faster and better polishing/buffing.

Polishing/Buffing alone will take much longer and on an instrument with considerable acid etch and scratches yield a very uneven or modeled surface.

We also use different wheels, especially when working on silver or gold plated finishes. The choice of wheel depends on the job to be done and desired results.

Oberloh plates the instrument in copper to fill up the scratches, and then sands away the copper down to the original level of the brass.

Uhh... no Rick, that is not correct. The only time I apply heavy copper plate (acid-copper build up) is when instruments have severe week spots or extensive crack repairs that must be incased in copper to avoid flaws in the final silver or gold plate. I do not sand the copper down to the substrate, only to the point of leveling and evening out the surface. The copper is then polished and prepared for silver, gold or nickel plate.

Daniel C.''Thinking the skill of the polisher delivers the desired results, more so then the the grit of the polish'' Oberloh

[tubaguy9]

During my time working in the plating biz, the process where tripoli is used was referred to by metal finishers as polishing or ''cutting''. When we are buffing, we are at the stage where very fine, visible scuffs were being addressed and the stage where the luster (or glow) is brought out is ''color buffing''. Color buffing is where rouge compound is applied and has a burnishing effect.

What about when there is possibly a buffing compund in between the tripoli (cut buffing) and the Rouge (color buffing)? Like that Nu-White or Yellow compound?

Buffing alone can and does remove more metal then the combination of sanding and then buffing.

Wish I had known that before...

tubaguy"who did something rather embarrassing in the repair lab today, and could tell you in a PM"9

[tubaguy9]

Daniel C.''Thinking the skill of the polisher delivers the desired results, more so then the the grit of the polish'' Oberloh

But what about the fact that the buffing wheel doesn't care who's buffing, and will chuck something at you even if you're experienced? And even if you aren't great, you can still do pretty well between cut buffing and color buffing. That yellow compound that the repair lab I'm at can get a good buff, too.

tubaguy"Who offers that he can get a good shine out of buffing, but doesn't think he's great at it"9

[Daniel C. Oberloh]

What about when there is possibly a buffing compund in between the tripoli (cut buffing) and the Rouge (color buffing)? Like that Nu-White or Yellow compound?

Oh Grass-Hopper-

White-diamond has its place but once you know how to polish copper alloys, you can skip it and go straight from tripoli to rouge and still get stunning results. Its all in knowing how and when to do it. Knowing the right combination of compound, correct wheels and how to prep them, surface feet per minute (SFM), pressure, wheel charge frequency, when and how to rake the wheel, direction of approach, etc. is how its done. When getting paid a flat rate for the job, we ether step up and master the skills or go do something else. I like to eat and I prefer to spend as little time in the polishing room as I need too so I got as much training as I could and I am really glad I did. I was lucky enough to learn from some of the best polishers in the business and though I am no slouch, they could still kick my butt nine ways from Sunday.


I just completed these overhauls and only polished with tripoli and rouge. Really, I have done thousands this way. and they look great.

But what about the fact that the buffing wheel doesn't care who's buffing, and will chuck something at you even if you're experienced?

Not true Grass-Hopper,

The wheel does as its told. If you are not telling it what to do then your head is not in the game (see rectal-cranial-inversion) but fear not, you will soon be snapped back into reality when the work is yanked from your hands and fired into the floor, wall, Polisher's forehead, pick a target. I guess the good thing about experience in polishing is that it helps reduce the frequency of disasters/accidents/oopsy-dasies. I still have my screw-ups but not as frequently as I did three decades ago.

tubaguy"Who offers that he can get a good shine out of buffing, but doesn't think he's great at it"9

Primary ingredients for success: Patience, observation, study, care, time and a wee bit of talent.

Hang in there...

And maybe this slice of hell can be yours


Daniel C. Oberloh


Oberloh Woodwind and Brass Works
Saving the world, one horn at a time...

[ztuba]

I wonder how much it would cost to gold plate a silver horn with gold being at 900 spot.

[The Big Ben]

I wonder how much it would cost to gold plate a silver horn with gold being at 900 spot.

A buttload. That's an actual amount. The number of doughnuts eaten by the LAPD in one week? That's a buttload.