21 ms·

Repairing a dented tuba with magnets

151 points by mixmax 15y ago

rhdoenges 15y ago
Wow, that is a nice tuba.
phaedrus 15y ago
The striking thing about this is not just that it works but that it works so well. That I did not expect.
hippich 15y ago
Too bad they do not ship to USA. Any clue why this could be? Because of magnetic field and air shipping? Also, any clue where I could find something similar in USA territory?
- ihartley 15y ago
  United Nuclear has super magnets: http://unitednuclear.com/index.php?main_page=index&cPath=70_80 http://unitednuclear.com/index.php?main_page=index&cPath...
- mixmax 15y ago
  I just ordered a few magnets from their site, including one that can lift 100 kg. (http://www.supermagnete.de/eng/FTN-63 http://www.supermagnete.de/eng/FTN-63) and worried about the exact same thing. There's a shipping guide on their site, and apparently it's not as problematic as you would think since you can "shortcircuit" a magnet by wrapping a piece of metal around it. The guide is here: http://www.supermagnete.de/eng/faq/shipping http://www.supermagnete.de/eng/faq/shipping
mrkurt 15y ago
Wow that beats the heck out of disconnecting the joints, rolling it out by hand, and then soldering everything back together. That would have saved me hours in high school. Plus, magnets.
- darklajid 15y ago
  I guess it's not only a time saver. Unless you actually would unroll/re-solder an instrument worth > 10000 EUR, which would scare the hell out of me. Funny trivia: The article uses ' as delimiter here, as in 10'000 although Germany (the domain name uses .DE and the company is based there) uses the . here -> 10.000 Seems like the author ('from Italy') of that post is using the swiss notation? Any other (european) country using ' as a thousand separator?
  - bsk26 15y ago
    I worked in a music shop during high school and pulled apart a few tubas worth at least that. We had a similar magnet tool, but it didn't always work perfectly, and could leave scars in the metal if you weren't careful. His tool might be better, or he might have gotten lucky. We certainly didn't try to unroll them, however, and I let my mentor solder them back together.
JonnieCache 15y ago
I'm sorely tempted to order one of their super-strong magnets, such as http://www.supermagnete.de/eng/K-26-C http://www.supermagnete.de/eng/K-26-C but I'm almost certain it'd lead to personal misfortune. I wonder if this one of those "regret the things you do, not the things you don't do" situations, or simply a "don't be an idiot" situation... EDIT: Just seen this one. Bloody hell. http://www.supermagnete.de/eng/SALE-038 http://www.supermagnete.de/eng/SALE-038 Also interesting, this page http://www.supermagnete.de/eng/faq/price http://www.supermagnete.de/eng/faq/price about how the price of neodymium "increased about fivefold between January 2011 and June 2011" due to china reducing export quotas.
- latch 15y ago
  "None of the women I know can separate these two magnetic spheres"
- dzuc 15y ago
  Really: be careful. Strong magnets are extremely dangerous. I once managed to get a 1" cube of neodymium stuck on either side of my hand for a few minutes.
  - mikiem 15y ago
    Think this is the very first thing anyone does when handed two pieces of neodymium. I know that I did this within a minute of my first experience with two free and loose neodymium magnets. I watched many others do it too. The look on one's face is always of shock and disbelief that this magnets were so strong, mixed in with the pain, even though you warned them before.
  - gsivil 15y ago
    To second your warning: http://www.supermagnete.de/eng/safety.php http://www.supermagnete.de/eng/safety.php
  - rcxdude 15y ago
    for a very graphic demonstration of the dangers of the larger magnets: http://www.geekologie.com/2009/02/guy_loses_finger_to_neodymium.php http://www.geekologie.com/2009/02/guy_loses_finger_to_neodym... (WARNING: gore)
zck 15y ago
That reverse hammer is fascinating. I'm a little confused by the diagram, though -- I think the magnet stays on the instrument's surface for the entire motion. It never comes away from the instrument, even after the hammerhead hits the stopper.
- fr0sty 15y ago
  It is called a slide hammer. The blow to the end of the shaft is transferred to the magnet on the opposite end and pulls the magnet inside.
phil 15y ago
That's very clever. Their "reverse hammer" is reminiscent of the climbing world's funkness device: http://books.google.com/books?id=vNyk_tSE2mUC&lpg=PP1&dq=big%20walls%20book&pg=PA23#v=onepage&q=funkness&f=false http://books.google.com/books?id=vNyk_tSE2mUC&lpg=PP1&#3...
BuddhaSource 15y ago
They use a similar techniques to repair dents on your car.
masterponomo 15y ago
In England, we don't dent the tuba.
iwwr 15y ago
Can this be used to repair bent car body panels?
- mrtron 15y ago
  The magnets would have to be so strong they would be dangerous to work with. The easier way is just weld rods on to pull a dent out with, and then chop the rod off. There are several dent pulling tools that work this way.
- reemrevnivek 15y ago
  Is your car body magnetic? If you had aluminum body panels, it probably could, though the panel is probably a good deal stiffer than this tuba. If you had steel body panels (which is very likely), it wouldn't.
MJR 15y ago
Very cool. I talked to a few of brass-playing musician friends and this is the standard process for getting rid of dents in brass instruments.

151 points by mixmax 15y ago

rhdoenges 15y ago

Wow, that is a nice tuba.

phaedrus 15y ago

The striking thing about this is not just that it works but that it works so well. That I did not expect.

hippich 15y ago

Too bad they do not ship to USA. Any clue why this could be? Because of magnetic field and air shipping? Also, any clue where I could find something similar in USA territory?

ihartley 15y ago
United Nuclear has super magnets: http://unitednuclear.com/index.php?main_page=index&cPath=70_80 http://unitednuclear.com/index.php?main_page=index&cPath...
mixmax 15y ago
I just ordered a few magnets from their site, including one that can lift 100 kg. (http://www.supermagnete.de/eng/FTN-63 http://www.supermagnete.de/eng/FTN-63) and worried about the exact same thing. There's a shipping guide on their site, and apparently it's not as problematic as you would think since you can "shortcircuit" a magnet by wrapping a piece of metal around it. The guide is here: http://www.supermagnete.de/eng/faq/shipping http://www.supermagnete.de/eng/faq/shipping

mrkurt 15y ago

Wow that beats the heck out of disconnecting the joints, rolling it out by hand, and then soldering everything back together. That would have saved me hours in high school. Plus, magnets.

darklajid 15y ago
I guess it's not only a time saver. Unless you actually would unroll/re-solder an instrument worth > 10000 EUR, which would scare the hell out of me. Funny trivia: The article uses ' as delimiter here, as in 10'000 although Germany (the domain name uses .DE and the company is based there) uses the . here -> 10.000 Seems like the author ('from Italy') of that post is using the swiss notation? Any other (european) country using ' as a thousand separator?
- bsk26 15y ago
  I worked in a music shop during high school and pulled apart a few tubas worth at least that. We had a similar magnet tool, but it didn't always work perfectly, and could leave scars in the metal if you weren't careful. His tool might be better, or he might have gotten lucky. We certainly didn't try to unroll them, however, and I let my mentor solder them back together.

JonnieCache 15y ago

I'm sorely tempted to order one of their super-strong magnets, such as http://www.supermagnete.de/eng/K-26-C http://www.supermagnete.de/eng/K-26-C but I'm almost certain it'd lead to personal misfortune. I wonder if this one of those "regret the things you do, not the things you don't do" situations, or simply a "don't be an idiot" situation... EDIT: Just seen this one. Bloody hell. http://www.supermagnete.de/eng/SALE-038 http://www.supermagnete.de/eng/SALE-038 Also interesting, this page http://www.supermagnete.de/eng/faq/price http://www.supermagnete.de/eng/faq/price about how the price of neodymium "increased about fivefold between January 2011 and June 2011" due to china reducing export quotas.

latch 15y ago
"None of the women I know can separate these two magnetic spheres"
dzuc 15y ago
Really: be careful. Strong magnets are extremely dangerous. I once managed to get a 1" cube of neodymium stuck on either side of my hand for a few minutes.
- mikiem 15y ago
  Think this is the very first thing anyone does when handed two pieces of neodymium. I know that I did this within a minute of my first experience with two free and loose neodymium magnets. I watched many others do it too. The look on one's face is always of shock and disbelief that this magnets were so strong, mixed in with the pain, even though you warned them before.
- gsivil 15y ago
  To second your warning: http://www.supermagnete.de/eng/safety.php http://www.supermagnete.de/eng/safety.php
- rcxdude 15y ago
  for a very graphic demonstration of the dangers of the larger magnets: http://www.geekologie.com/2009/02/guy_loses_finger_to_neodymium.php http://www.geekologie.com/2009/02/guy_loses_finger_to_neodym... (WARNING: gore)

zck 15y ago

That reverse hammer is fascinating. I'm a little confused by the diagram, though -- I think the magnet stays on the instrument's surface for the entire motion. It never comes away from the instrument, even after the hammerhead hits the stopper.

fr0sty 15y ago
It is called a slide hammer. The blow to the end of the shaft is transferred to the magnet on the opposite end and pulls the magnet inside.

phil 15y ago

That's very clever. Their "reverse hammer" is reminiscent of the climbing world's funkness device: http://books.google.com/books?id=vNyk_tSE2mUC&lpg=PP1&dq=big%20walls%20book&pg=PA23#v=onepage&q=funkness&f=false http://books.google.com/books?id=vNyk_tSE2mUC&lpg=PP1&#3...

BuddhaSource 15y ago

They use a similar techniques to repair dents on your car.

masterponomo 15y ago

In England, we don't dent the tuba.

iwwr 15y ago

Can this be used to repair bent car body panels?

mrtron 15y ago
The magnets would have to be so strong they would be dangerous to work with. The easier way is just weld rods on to pull a dent out with, and then chop the rod off. There are several dent pulling tools that work this way.
reemrevnivek 15y ago
Is your car body magnetic? If you had aluminum body panels, it probably could, though the panel is probably a good deal stiffer than this tuba. If you had steel body panels (which is very likely), it wouldn't.

MJR 15y ago

Very cool. I talked to a few of brass-playing musician friends and this is the standard process for getting rid of dents in brass instruments.