Question for Repair Techs

Jedi Master · Post by **Jedi Master** » Wed Jul 19, 2006 10:38 pm

Dear Repair Techs:

I am very upset that I put a dent in my brand new tuba, tonight, at a concert where we were fairly tightly packed. I bumped the horn into a chair, and dented it (actually more of an indentation, about the size of a quarter), much to my horror.

Here is the physical location of the dent:

My question: Is it possible to remove the dent, without disassemling the horn? Would the dent eraser be over kill? (the brass is fairly thin)

I would like to restore the horn to it's original condition.

Thanks in advance!

Jedi Master · Post by **Jedi Master** » Wed Jul 19, 2006 11:03 pm

Hmmm....I tried to fix it (the link, that is....). Did it work?

DaTubaKid · Post by **DaTubaKid** » Thu Jul 20, 2006 12:12 am

You can just open a new window, and copy and paste the link into the new window. Worked for me!

pulseczar · Post by **pulseczar** » Thu Jul 20, 2006 2:30 am

As an apprentice working at a repair shop and observing my master inspect horns, I would say that to remove that dent traditionally, it would require disassmbly. The dent eraser may work. However, there are alot of repairmen who do not use the Dent Eraser because it is very easy to hurt yourself using it, plus these magnets are so strong that they have to be stored at least 10 feet away from anything ferrous to be safe.

My .002 cents (because the opinions of REAL repairmen on this board weigh alot more than mine) is just to live with it because if it's quarter sized, it's only cosmetic and not worth the money and trouble to get rid of and the magnetic tools might do more harm than help, depending whether or not the repairman is experienced enough.

Daniel C. Oberloh · Post by **Daniel C. Oberloh** » Thu Jul 20, 2006 3:12 am

pulseczar wrote:My .002 cents (because the opinions of REAL repairmen on this board weigh alot more than mine) is just to live with it because if it's quarter sized, it's only cosmetic and not worth the money and trouble to get rid of and the magnetic tools might do more harm than help, depending whether or not the repairman is experienced enough.

Good call.

Daniel C. Oberloh

cambrook · Post by **cambrook** » Thu Jul 20, 2006 3:35 am

Sorry to hear about your accident, I still remember the anguish of the time I "christened" my first tuba about 30 years ago, and that tuba wasn't anything like as good as yours. I'm about to get a new Willson Eb, and I'm not looking forward to the time it gets its first (hopefully very small) dent.

I'm not any sort of repairman, and I take seriously the advice of good repair people about using "dent balls" and their very strong magnets with extreme caution. I wonder if some of the dangers of this system would be lessened if the very strong (neodymium?) magnets were replaced with an electromagnet? This would allow the force to be applied gradually, and also adjusted to suit the particular instrument/application. Would this make dent balls more usable?

Naptown Tuba · Post by **Naptown Tuba** » Thu Jul 20, 2006 3:52 am

It was going to happen sooner or later, no matter how careful you are. Just wait till you get your first "ding" in your first "new" car. It hurts about as bad as in your tuba. If you're not made of money, you'll just live with it, and those "dings" are a constant reminder to try and be more careful in the future. My simpathies are with you. I remember my first new tuba and new car "ding" all too well.

But now, your horn has a personal characteristic that makes it unmistakably your own.

Daniel C. Oberloh · Post by **Daniel C. Oberloh** » Thu Jul 20, 2006 4:05 am

cambrook wrote: I wonder if some of the dangers of this system would be lessened if the very strong (neodymium?) magnets were replaced with an electromagnet? This would allow the force to be applied gradually, and also adjusted to suit the particular instrument/application. Would this make dent balls more usable?

There may be an answer for you here.

http://www.ferreestools.com/magnetic_dent_tools.htm

Daniel C. Oberloh
Oberloh Woodwind and Brass Works
Seattle, WA
206.241.5767
www.oberloh.com

Chuck(G) · Post by **Chuck(G)** » Thu Jul 20, 2006 12:34 pm

Given the location of the dent, no one but you will probably even know it's there. It doesn't sound as if it's large enough to affect playability , so I'd just leave it be if I were you.

Chalk it up as the first scratch in a new car's paint. The first one's always the most difficult to live with; after that, it's just another "Oh, damn" situation.

iiipopes · Post by **iiipopes** » Thu Jul 20, 2006 1:41 pm

Life...is just a bowl of...cher---ries....

DBCooper · Post by **DBCooper** » Thu Jul 20, 2006 1:45 pm

Chuck(G) · Post by **Chuck(G)** » Thu Jul 20, 2006 2:42 pm

Hmmm...

I was under the impression that a fly cutter required a drill press or lathe...

iiipopes · Post by **iiipopes** » Thu Jul 20, 2006 2:47 pm

Hey DB - thanks.

prototypedenNIS · Post by **prototypedenNIS** » Thu Jul 20, 2006 7:32 pm

MDRS should work fine (dent eraser)

Z-Tuba Dude · Post by **Z-Tuba Dude** » Thu Jul 20, 2006 11:10 pm

Does the dent eraser have magnets of varying strengths, as well as different sized balls?

ASTuba · Post by **ASTuba** » Fri Jul 21, 2006 9:06 am

Z-Tuba Dude wrote:Does the dent eraser have magnets of varying strengths, as well as different sized balls?

Folks,

The Dent Eraser, IMO, is a toy. It has one magnet and 4 or 5 dent balls with it. It's very cumbersome, hard to use, and really hard to take dents out without leaving lots of scratches.

The Magnetic Dent Removal System, or MDRS, is a real tool that can actually be used to take dents out. It has several different sizes of magnets, with either a flat or radial surface. However, I don't use it on all brands/types of instruments. It's designed to rough out dents in instruments for schools that they wouldn't normally want to have dent work done by traditional methods, as they are too labor intensive.

MDRS will not work on handmade tubas, I've seen several that have been damaged my magnet tools, in particular ones that haven't been cleaned properly before hand.

Just my thoughts on the systems.

Rick Denney · Post by **Rick Denney** » Fri Jul 21, 2006 10:29 am

Z-Tuba Dude wrote:Does the dent eraser have magnets of varying strengths, as well as different sized balls?

The Dent Eraser has only one magnet, but the force of the pull is related to the amount of magnetic material which it is attracting. So, it draws the large ball with considerably more force than the small ball.

It works best on moderately thick brass that does not have an especially fragile finish, and then only if you use it just right. If the surface of the magnet is covered with something soft, it won't scratch, but it may pull ridges into the brass. If the surface is hard enough to prevent that, it can scratch. If the brass is too thin, you'll probably get ridges anyway. Any irregularities on the inside surface of the isntrument (as you'll find on hand-hammered bows that have been sanded smooth), will reflect thorugh to the outside.

It's useful for raising dents on instruments that are not perfect, to make them a little more presentable, such as school horns or those in raw brass. If you want to restore perfection, there's no substitute for a thousand well-aimed taps with a dent hammer, or careful working with a polished burnisher, with a proper set of dent balls or mandrels. Hint: The aiming is the hard part.

Rick "who can turn dents into ripples" Denney

Dan Schultz · Post by **Dan Schultz** » Fri Jul 21, 2006 10:40 am

ASTuba wrote:
Z-Tuba Dude wrote:Does the dent eraser have magnets of varying strengths, as well as different sized balls?
Folks, (in my opinion) The Dent Eraser, IMO, is a toy. ....
Just my thoughts.....

What Andy says is true. HOWEVER I use my home-brewed version of the Dent Eraser/MDRS on a daily basis for taking our all sorts of dents... including working on smaller tubes like slide crooks, etc. The system will not work on branches that have an unfinished seam on the inside and won't work on reinforced areas such as are found on most bottom bows. If a person first takes off the guard wire and guard plate, a certain amount of work can be done without removing the bottom bow from the horn. The magnetic systems are not very friendly with lacquer or silver-plate finishes at they leave scratches. Using padding on the face of the magnet to avoid scratches can result in leaving 'ball tracks' on the inside of the horn that are the reverse of a dent. I spend a lot of time working on raw brass horns and don't worry much about a few small scratches as long as light buffing will get rid of them. I also do lots of work on student horns where even though the finish matters somewhat, what the band director really wants to get rid of is the dents. Basically, this amounts to: 1) do you want me to get rid of the dents and spritz on some touch-up lacquer for $50... or 2) do you want a complete restoration for $400. Granted, there are a few of you who want the 'whole enchilada'... but most will go for the $50 'quickie'. (don't know if I spelled 'enchilada' right or not... but I'm sure someone will let me know if I didn't!).

Changing all the lacquered horns in The World to raw brass... one at a time!

Rick Denney · Post by **Rick Denney** » Fri Jul 21, 2006 10:51 am

TubaTinker wrote:don't know if I spelled 'enchilada' right or not...

You nailed it. Of course, around here people pronounce as though it's French: AHN-shi-la-da, instead of Spanish, In-chee-LAH-dah.

Considering all our "guest workers" in these parts, you'd think gringo-mouth would be on the wane. But of course lots of folks around here pronounce English words with accents from all sorts of odd corners of the world.

Rick "including West Virginia" Denney

MaryAnn · Post by **MaryAnn** » Fri Jul 21, 2006 11:25 am

On the scratches from removing dents concept....I always wondered why a piece of chamois isn't put between the tool and the outside of the horn? Once when I had a dent taken out of my raw brass bell, the repair person rubbed my bell on this very scratched up, grooved even, fist-shaped metal arm thing, scratching up the bell, and then used some abrasive stuff to take the scratches out of the very thin bell. It seemed like it would have been less work to simply put something between the bell and the tool, like a piece of thin chamois, and it also would have prevented the scratches and subsequent burnishing.

MA