How to make a valve? and a bell?
- Elow
- Posts: 1924
- Joined: Mar 02, 2020
Hi, this might not be the right place to put this so move me where you think it should go. A couple years ago i bought a pretty mint condition beuscher mellophone from i think 1907. It was pretty cheap and i really like it, only problem was the first valve. It looked like it had been best to hell and back, literally. It had so many dents in it. I took it to my local repair shop and they gave me two options, to have a third party make a new valve, or a cheaper option that might not work, which it did btw. So i had that all taken care of, but i’m curious as to how someone would make a whole new valve. It’s a piston so i imagine the cylinder could be spun up in a lathe, but then what? I’d really love to know. Also what’s the process of making a bell? Are there specialized people for this, or is it a big shop that would make a custom valve?
- BGuttman
- Posts: 7368
- Joined: Mar 22, 2018
Making a bell is not for the faint of heart. There is a Mirafone video on YouTube showing how a tuba is made and there are all the steps in bell making. It's a VERY skilled trade.
Look for a trumpet making video on YouTube. I think one of them shows how a valve is made. Its more than spinning one on a lathe.
For 3 valve instruments often the best option is to graft in a new full cluster (all 3 valves with casings). Many makers used to do this. Blessing had a reputation for making valve clusters for other makers.
Just replacing one valve in a cluster can have serious soldering problems.
Look for a trumpet making video on YouTube. I think one of them shows how a valve is made. Its more than spinning one on a lathe.
For 3 valve instruments often the best option is to graft in a new full cluster (all 3 valves with casings). Many makers used to do this. Blessing had a reputation for making valve clusters for other makers.
Just replacing one valve in a cluster can have serious soldering problems.
- harrisonreed
- Posts: 6479
- Joined: Aug 17, 2018
<YOUTUBE id="4gnXUja50T0">[media]https://youtu.be/4gnXUja50T0</YOUTUBE>
Step 1: acquire $70,000+ worth of tooling
Step 2: learn how to not cut your hand open while cutting sheet brass with scissors
Step 3: learn how to not burn your house down while torching the seam
Step 4: learn how to safely operate the lathe and not maim yourself while spinning a brass buzzsaw that will become the flare.
Step 5: learn how to not burn yourself while torching the flare.
Step 5.5: practice making bells until they aren't just bell shaped objects. This may involve learning buffing techniques and other treatments that are a huge part of what makes bells respond the way they do.
Step 6: acquire another $50-100k worth of CNC machines.
Step 7: learn CAD
Step 8: learn how to CNC a rotor core
Step 9: ...
You know who knows how to do all these things is Christan Griego. The staff at SE Shires also know how to these things. If you are interested in instrument building, these are the guys to try to work for.
Step 1: acquire $70,000+ worth of tooling
Step 2: learn how to not cut your hand open while cutting sheet brass with scissors
Step 3: learn how to not burn your house down while torching the seam
Step 4: learn how to safely operate the lathe and not maim yourself while spinning a brass buzzsaw that will become the flare.
Step 5: learn how to not burn yourself while torching the flare.
Step 5.5: practice making bells until they aren't just bell shaped objects. This may involve learning buffing techniques and other treatments that are a huge part of what makes bells respond the way they do.
Step 6: acquire another $50-100k worth of CNC machines.
Step 7: learn CAD
Step 8: learn how to CNC a rotor core
Step 9: ...
You know who knows how to do all these things is Christan Griego. The staff at SE Shires also know how to these things. If you are interested in instrument building, these are the guys to try to work for.
- JohnL
- Posts: 2529
- Joined: Mar 23, 2018
[quote="Elow"]So i had that all taken care of, but i’m curious as to how someone would make a whole new valve.[/quote]
Here's some basic info from Yamaha:
<LINK_TEXT text="https://www.yamaha.com/en/musical_instr ... ng002.html">https://www.yamaha.com/en/musical_instrument_guide/trumpet/manufacturing/manufacturing002.html</LINK_TEXT>
<LINK_TEXT text="https://www.yamaha.com/en/musical_instr ... ng003.html">https://www.yamaha.com/en/musical_instrument_guide/trumpet/manufacturing/manufacturing003.html</LINK_TEXT>
There's several more processes involved that they don't get into. The valve guide and valve guide slots. Making the ends of the piston. Fitting everything up. Top and bottom caps for the casing. The spring carrier, if it's a top-sprung valve. Fitting it all together so it works. Plating the piston (not all pistons are plated, but most are).
Repair shops, even big ones, don't usually make valves. It's fairly common for small manufacturers to buy their valve clusters from someone else; as mentioned earlier, E. K. Blessing used to make clusters for a lot of people. Kanstul used to supply valves to several small custom builders, which put them in a bad spot when Kanstul shut down.
If you have an otherwise nice instrument with a munched valve, the normal repair process is to try to find a replacement from a donor instrument (preferably the same make & model). That's why a lot of techs have big boneyeards. If you're lucky, the piston will just drop in and work, but it'll probably need some fitting.
Here's some basic info from Yamaha:
<LINK_TEXT text="https://www.yamaha.com/en/musical_instr ... ng002.html">https://www.yamaha.com/en/musical_instrument_guide/trumpet/manufacturing/manufacturing002.html</LINK_TEXT>
<LINK_TEXT text="https://www.yamaha.com/en/musical_instr ... ng003.html">https://www.yamaha.com/en/musical_instrument_guide/trumpet/manufacturing/manufacturing003.html</LINK_TEXT>
There's several more processes involved that they don't get into. The valve guide and valve guide slots. Making the ends of the piston. Fitting everything up. Top and bottom caps for the casing. The spring carrier, if it's a top-sprung valve. Fitting it all together so it works. Plating the piston (not all pistons are plated, but most are).
Repair shops, even big ones, don't usually make valves. It's fairly common for small manufacturers to buy their valve clusters from someone else; as mentioned earlier, E. K. Blessing used to make clusters for a lot of people. Kanstul used to supply valves to several small custom builders, which put them in a bad spot when Kanstul shut down.
If you have an otherwise nice instrument with a munched valve, the normal repair process is to try to find a replacement from a donor instrument (preferably the same make & model). That's why a lot of techs have big boneyeards. If you're lucky, the piston will just drop in and work, but it'll probably need some fitting.
- Amconk
- Posts: 279
- Joined: Jun 14, 2018
I’m curious how the factories overseas make bells. Do they actually have people on a lathe spinning out a bell? Or are they machine spun? For the thousands of the stencil trombone shaped objects that they turn out, I have to suspect it’s automated.
- BGuttman
- Posts: 7368
- Joined: Mar 22, 2018
The video from Yamaha shows a person spinning the bell.
The video from Rath shows a person spinning the bell'
I haven't seen any videos from Chinese factories.
The video from Rath shows a person spinning the bell'
I haven't seen any videos from Chinese factories.
- Elow
- Posts: 1924
- Joined: Mar 02, 2020
[quote="harrisonreed"]<YOUTUBE id="4gnXUja50T0">[media]https://youtu.be/4gnXUja50T0</YOUTUBE>
Step 1: acquire $70,000+ worth of tooling
Step 2: learn how to not cut your hand open while cutting sheet brass with scissors
Step 3: learn how to not burn your house down while torching the seam
Step 4: learn how to safely operate the lathe and not maim yourself while spinning a brass buzzsaw that will become the flare.
Step 5: learn how to not burn yourself while torching the flare.
Step 5.5: practice making bells until they aren't just bell shaped objects. This may involve learning buffing techniques and other treatments that are a huge part of what makes bells respond the way they do.
Step 6: acquire another $50-100k worth of CNC machines.
Step 7: learn CAD
Step 8: learn how to CNC a rotor core
Step 9: ...
You know who knows how to do all these things is Christan Griego. The staff at SE Shires also know how to these things. If you are interested in instrument building, these are the guys to try to work for.[/quote]
Just watched the video again and something stuck out to me. When i was at an all state convention i talked to a bassoon salesman and tried a bunch of super expensive bocals (the metal tube that connects reed to instrument) and he was talking about the differences of each one and somehow we got into how they were made. He said after the tube is made they melt a pretty soft metal into it so that it doesn’t crack when bent, which is what that video showed but instead to metal it’s ice. I’m sure they both work, but i would assume ice works better. I just thought that was something to point out.
Step 1: acquire $70,000+ worth of tooling
Step 2: learn how to not cut your hand open while cutting sheet brass with scissors
Step 3: learn how to not burn your house down while torching the seam
Step 4: learn how to safely operate the lathe and not maim yourself while spinning a brass buzzsaw that will become the flare.
Step 5: learn how to not burn yourself while torching the flare.
Step 5.5: practice making bells until they aren't just bell shaped objects. This may involve learning buffing techniques and other treatments that are a huge part of what makes bells respond the way they do.
Step 6: acquire another $50-100k worth of CNC machines.
Step 7: learn CAD
Step 8: learn how to CNC a rotor core
Step 9: ...
You know who knows how to do all these things is Christan Griego. The staff at SE Shires also know how to these things. If you are interested in instrument building, these are the guys to try to work for.[/quote]
Just watched the video again and something stuck out to me. When i was at an all state convention i talked to a bassoon salesman and tried a bunch of super expensive bocals (the metal tube that connects reed to instrument) and he was talking about the differences of each one and somehow we got into how they were made. He said after the tube is made they melt a pretty soft metal into it so that it doesn’t crack when bent, which is what that video showed but instead to metal it’s ice. I’m sure they both work, but i would assume ice works better. I just thought that was something to point out.
- brassmedic
- Posts: 1447
- Joined: Dec 14, 2018
[quote="Amconk"]I’m curious how the factories overseas make bells. Do they actually have people on a lathe spinning out a bell? Or are they machine spun? For the thousands of the stencil trombone shaped objects that they turn out, I have to suspect it’s automated.[/quote]
I've never seen a machine spinning a bell. Maybe it's done, but I haven't heard of it. It takes a pretty sensitive touch to spin a bell correctly. I think labor is pretty cheap in the countries that are making cheap trombones, so it wouldn't be particularly expensive to hand spin them all. I just googled what a machinist makes in India and it said 15000 rupees per month average, which is about $200. I also don't know if stamping a whole bell on a machine is done. I know some factories stamp out the bell stem at least.
I've never seen a machine spinning a bell. Maybe it's done, but I haven't heard of it. It takes a pretty sensitive touch to spin a bell correctly. I think labor is pretty cheap in the countries that are making cheap trombones, so it wouldn't be particularly expensive to hand spin them all. I just googled what a machinist makes in India and it said 15000 rupees per month average, which is about $200. I also don't know if stamping a whole bell on a machine is done. I know some factories stamp out the bell stem at least.
- BGuttman
- Posts: 7368
- Joined: Mar 22, 2018
[quote="Elow"]...
Just watched the video again and something stuck out to me. When i was at an all state convention i talked to a bassoon salesman and tried a bunch of super expensive bocals (the metal tube that connects reed to instrument) and he was talking about the differences of each one and somehow we got into how they were made. He said after the tube is made they melt a pretty soft metal into it so that it doesn’t crack when bent, which is what that video showed but instead to metal it’s ice. I’m sure they both work, but i would assume ice works better. I just thought that was something to point out.[/quote]
Before the use of ice or bending metal they used pitch to prevent tubes from collapsing. Mainly because in the era before mechanical refrigeration and before the low melting alloy was invented that was the best available.
Just watched the video again and something stuck out to me. When i was at an all state convention i talked to a bassoon salesman and tried a bunch of super expensive bocals (the metal tube that connects reed to instrument) and he was talking about the differences of each one and somehow we got into how they were made. He said after the tube is made they melt a pretty soft metal into it so that it doesn’t crack when bent, which is what that video showed but instead to metal it’s ice. I’m sure they both work, but i would assume ice works better. I just thought that was something to point out.[/quote]
Before the use of ice or bending metal they used pitch to prevent tubes from collapsing. Mainly because in the era before mechanical refrigeration and before the low melting alloy was invented that was the best available.
- paulyg
- Posts: 689
- Joined: May 17, 2018
Your best bet for that mellophone is probably to get a donor valve block (probably any student trumpet will be fine) and just work with the bell you have.
Forget about making a valve from scratch- that's a $500,000 solution to a $100 problem.
Forget about making a valve from scratch- that's a $500,000 solution to a $100 problem.
- JohnL
- Posts: 2529
- Joined: Mar 23, 2018
[quote="paulyg"]Your best bet for that mellophone is probably to get a donor valve block (probably any student trumpet will be fine) and just work with the bell you have.[/quote]
If you're lucky, you might actually end up with a better set of valves than when it was new. Mellos were generally built to student instrument standards.
[quote="Elow"]i would assume ice works better.[/quote]
I don't know if it necessarily works better, but the cleanup is sure a lot easier.
If you're lucky, you might actually end up with a better set of valves than when it was new. Mellos were generally built to student instrument standards.
[quote="Elow"]i would assume ice works better.[/quote]
I don't know if it necessarily works better, but the cleanup is sure a lot easier.
- timothy42b
- Posts: 1812
- Joined: Mar 27, 2018
[quote="BGuttman"]
For 3 valve instruments often the best option is to graft in a new full cluster (all 3 valves with casings). Many makers used to do this. Blessing had a reputation for making valve clusters for other makers.
[/quote]
This.
IMO spinning a bell, particularly of that size, is not within amateur abilities or equipment.
Smaller bells are sometimes hand hammered successfully, but now you need to make a solid mandrel, and you'll be repeatedly annealing as brass work hardens.
If I had my heart set on a bell replacement, I would do a wet layup fiberglas bell. You will need a form to lay up on, but it doesn't have to withstand hammering. Auto designers do it with plywood and clay for prototypes. Some time ago I made a trombone bell form with styrofoam and masking tape. That first attempt was not very good, but with some practice and experimentation you could probably make one. If you had access to a lathe you could "turn" one easily out of soft wood or one of the harder waxes.
Then before using fiberglas, do a test run with papier mache. That was where I stopped. I did get a bell but it was frustratingly difficult to cover a flare. It's not a cone that flat pieces can "tile" to. Anyway, I would do a test layup with papier mache then proceed to a fiberglas construction. Caution: auto body repair kits are cheap but they use polyester resin instead of epoxy. That's not as strong and it is more of a health risk because of vapors. If I were ready to make a keeper I'd use one of the epoxy resins like boat builders and gliders use, like a West System.
For 3 valve instruments often the best option is to graft in a new full cluster (all 3 valves with casings). Many makers used to do this. Blessing had a reputation for making valve clusters for other makers.
[/quote]
This.
IMO spinning a bell, particularly of that size, is not within amateur abilities or equipment.
Smaller bells are sometimes hand hammered successfully, but now you need to make a solid mandrel, and you'll be repeatedly annealing as brass work hardens.
If I had my heart set on a bell replacement, I would do a wet layup fiberglas bell. You will need a form to lay up on, but it doesn't have to withstand hammering. Auto designers do it with plywood and clay for prototypes. Some time ago I made a trombone bell form with styrofoam and masking tape. That first attempt was not very good, but with some practice and experimentation you could probably make one. If you had access to a lathe you could "turn" one easily out of soft wood or one of the harder waxes.
Then before using fiberglas, do a test run with papier mache. That was where I stopped. I did get a bell but it was frustratingly difficult to cover a flare. It's not a cone that flat pieces can "tile" to. Anyway, I would do a test layup with papier mache then proceed to a fiberglas construction. Caution: auto body repair kits are cheap but they use polyester resin instead of epoxy. That's not as strong and it is more of a health risk because of vapors. If I were ready to make a keeper I'd use one of the epoxy resins like boat builders and gliders use, like a West System.
- Elow
- Posts: 1924
- Joined: Mar 02, 2020
[quote="BGuttman"]<QUOTE author="Elow" post_id="118389" time="1593651814" user_id="8680">
...
Just watched the video again and something stuck out to me. When i was at an all state convention i talked to a bassoon salesman and tried a bunch of super expensive bocals (the metal tube that connects reed to instrument) and he was talking about the differences of each one and somehow we got into how they were made. He said after the tube is made they melt a pretty soft metal into it so that it doesn’t crack when bent, which is what that video showed but instead to metal it’s ice. I’m sure they both work, but i would assume ice works better. I just thought that was something to point out.[/quote]
Before the use of ice or bending metal they used pitch to prevent tubes from collapsing. Mainly because in the era before mechanical refrigeration and before the low melting alloy was invented that was the best available.
</QUOTE>
Do you have anywhere where i could read about that? That seems like a cool concept and i’d like to learn more about it.
...
Just watched the video again and something stuck out to me. When i was at an all state convention i talked to a bassoon salesman and tried a bunch of super expensive bocals (the metal tube that connects reed to instrument) and he was talking about the differences of each one and somehow we got into how they were made. He said after the tube is made they melt a pretty soft metal into it so that it doesn’t crack when bent, which is what that video showed but instead to metal it’s ice. I’m sure they both work, but i would assume ice works better. I just thought that was something to point out.[/quote]
Before the use of ice or bending metal they used pitch to prevent tubes from collapsing. Mainly because in the era before mechanical refrigeration and before the low melting alloy was invented that was the best available.
</QUOTE>
Do you have anywhere where i could read about that? That seems like a cool concept and i’d like to learn more about it.
- Crazy4Tbone86
- Posts: 1654
- Joined: Jan 14, 2020
Bending tubes is an art. I imagine that there are some techs on Trombonechat that are far better at it than me. The videos and little tips on this thread are just the tip of the iceberg.
Back in the old days, instrument makers used lead to bend tubing. It was effective in creating a smooth, slow bend that was easy to control. As far as I know, some German brass makers still use lead but it is essentially illegal in the USA because the lead is so toxic.
When lead fell out of favor, pitch was created. This is what I use, but I do not consider myself a specialist at it. Pitch is a combination of pine tar and other ingredients. You must be very careful with pitch because if it gets too hot, it can bubble and explode. For this reason, when pitch is removed from tubing it should be melted slowly from one end of the tube to the other. Pitch is only effective in a small temperature range.....I always bend tubing in a 72 degree room. If the tube is too hot, the pitch is too soft. If the pitch is too cold, it is is too stiff. It is also a pain to remove the remnants of pitch in the tubing. The tubing must be heated to cherry red and the remaining pitch turns into a powder. The powder must then be scrubbed out with a brush.
Ice bending or "cerrobending" is a more modern technique. It is not just ice because the ice is too stiff. It is a mixture of ice and softeners. The cerrobending in the videos is a water/chemical combination that is very controlled. A person can create a cerrobend mixture with water and dish washing soap. Again, the mixture needs to be correct for a smooth bend. I tried to create a good cerrobend mixture years ago and never got it to be as predictable as my pitch......so I went back to pitch.
I think Brad Close does a lot of tube bending, so he can probably explain things better than me. Eric Edwards might do some tube bending as well.
Back in the old days, instrument makers used lead to bend tubing. It was effective in creating a smooth, slow bend that was easy to control. As far as I know, some German brass makers still use lead but it is essentially illegal in the USA because the lead is so toxic.
When lead fell out of favor, pitch was created. This is what I use, but I do not consider myself a specialist at it. Pitch is a combination of pine tar and other ingredients. You must be very careful with pitch because if it gets too hot, it can bubble and explode. For this reason, when pitch is removed from tubing it should be melted slowly from one end of the tube to the other. Pitch is only effective in a small temperature range.....I always bend tubing in a 72 degree room. If the tube is too hot, the pitch is too soft. If the pitch is too cold, it is is too stiff. It is also a pain to remove the remnants of pitch in the tubing. The tubing must be heated to cherry red and the remaining pitch turns into a powder. The powder must then be scrubbed out with a brush.
Ice bending or "cerrobending" is a more modern technique. It is not just ice because the ice is too stiff. It is a mixture of ice and softeners. The cerrobending in the videos is a water/chemical combination that is very controlled. A person can create a cerrobend mixture with water and dish washing soap. Again, the mixture needs to be correct for a smooth bend. I tried to create a good cerrobend mixture years ago and never got it to be as predictable as my pitch......so I went back to pitch.
I think Brad Close does a lot of tube bending, so he can probably explain things better than me. Eric Edwards might do some tube bending as well.
- hornbuilder
- Posts: 1384
- Joined: May 02, 2018
Cerrobend is the brand name of a low melting temperature metal alloy that is very useful for bending thin wall tubing. There are others, but the word Cerrobend has become synonymous with these types of materials. They are sold as ingots, and can be melted in a pan on a hotplate.
- Crazy4Tbone86
- Posts: 1654
- Joined: Jan 14, 2020
Really? Cerrobend is an alloy? I always thought is was a brand of water/detergent mix used for frozen bending. Never used the brand "Cerrobend" so I obviously assumed the wrong thing. Thanks for setting me straight on that. Obviously, I should have called my water and Palmolive mixture something different!
Matt, what do you use to bend tubing at M & W?
Matt, what do you use to bend tubing at M & W?
- JohnL
- Posts: 2529
- Joined: Mar 23, 2018
Cerrobend is actually a trade name for "Wood's Metal"; it melts at 70 °C (158 °F), while lead melts at 327.5°C (621.5°F). You can melt Cerrobend in a double boiler on a kitchen stove. Lead? Yeah, you're gonna need some more specialized equipment.
Wood's metal is 50% bismuth, 26.7% lead, 13.3% tin, and 10% cadmium. Definitely not non-toxic.
Ice bending is great as far as using non-toxic materials, but it requires some tight process controls to get the temperature and mixture just right. Practical on an industrial scale, but probably not so for a small shop. I've also heard that it really doesn't work as well as pitch or Cerrobend, so there's usually additional forming steps required.
Wood's metal is 50% bismuth, 26.7% lead, 13.3% tin, and 10% cadmium. Definitely not non-toxic.
Ice bending is great as far as using non-toxic materials, but it requires some tight process controls to get the temperature and mixture just right. Practical on an industrial scale, but probably not so for a small shop. I've also heard that it really doesn't work as well as pitch or Cerrobend, so there's usually additional forming steps required.
- Crazy4Tbone86
- Posts: 1654
- Joined: Jan 14, 2020
Wow, I love it when people throw in all the chemistry. I find so much on this forum educational. Being that Cerrobend has lead in it, I wonder if it was developed in order to provide a bending medium that was less toxic than pure lead?!?
I just remember when I worked in a retail shop, some of the craftsmen advised... "don't use Cerrobend, just make your own water + dishwashing soap mixture and freeze it, or stick with the pitch." That is why I assumed that Cerrobend was a pre-mixed frozen medium. I guess the old phrase applies......"when you assume, you make an ASS out U and ME!"
It is interesting how lead has historically been such an integral part of brass instrument making. There is lead in the soft solder that we use regularly to assemble instruments. Over the years, I have become accustomed to washing my hands thoroughly after doing any soldering work. More so now because the soldering flux is nasty, acidic stuff, but I remember being very aware that solder has lead in it and wanting to clean it off my hands when I first started soldering.
Lead has also been an invaluable part of the percussion sections in elementary, middle and high school bands. Whenever you have a percussion student who has no rhythm or pulse, it is best to give them a large lead block and ask them to tap the pulse with a soft yarn mallet. Just kidding of course.....but oh, have I been tempted to do that with many a student.
I just remember when I worked in a retail shop, some of the craftsmen advised... "don't use Cerrobend, just make your own water + dishwashing soap mixture and freeze it, or stick with the pitch." That is why I assumed that Cerrobend was a pre-mixed frozen medium. I guess the old phrase applies......"when you assume, you make an ASS out U and ME!"
It is interesting how lead has historically been such an integral part of brass instrument making. There is lead in the soft solder that we use regularly to assemble instruments. Over the years, I have become accustomed to washing my hands thoroughly after doing any soldering work. More so now because the soldering flux is nasty, acidic stuff, but I remember being very aware that solder has lead in it and wanting to clean it off my hands when I first started soldering.
Lead has also been an invaluable part of the percussion sections in elementary, middle and high school bands. Whenever you have a percussion student who has no rhythm or pulse, it is best to give them a large lead block and ask them to tap the pulse with a soft yarn mallet. Just kidding of course.....but oh, have I been tempted to do that with many a student.
- JohnL
- Posts: 2529
- Joined: Mar 23, 2018
[quote="Crazy4Tbone86"]Wow, I love it when people throw in all the chemistry. I find so much on this forum educational. Being that Cerrobend has lead in it, I wonder if it was developed in order to provide a bending medium that was less toxic than pure lead?!?[/quote]
Doubtful. Cadmium is pretty nasty. I suspect it was more about developing something that was easier to work with.
Doubtful. Cadmium is pretty nasty. I suspect it was more about developing something that was easier to work with.
- LeTromboniste
- Posts: 1634
- Joined: Apr 11, 2018
A little comment on the tangent of lead and toxicity. There hasn't been serious studies on what effects of any that might have on our health but it's worth also remembering that here is lead in virtually every brass mouthpiece, as industrial brass meant to be turned on a lathe almost always contains lead, typically around 2 to 5%. Between that and the soft solder at every joint, our instruments are definitely not lead free. Using lead for tube bending likely has some health risks for the instrument maker, but AFAIK it's pretty easy to get out and clean from the tube so I wouldn't think it carries much risk to the player.
- Aftess
- Posts: 3
- Joined: Nov 23, 2020
[quote="timothy42b"]<QUOTE author="BGuttman" post_id="118162" time="1593493220" user_id="53">
For 3 valve instruments often the best option is to graft in a new full cluster (all 3 valves with casings). Many makers used to do this. Blessing had a reputation for making valve clusters for other makers.
[/quote]
This.
IMO spinning a bell, particularly of that size, is not within amateur abilities or equipment.
Smaller bells are sometimes hand hammered successfully, but now you need to make a solid mandrel, and you'll be repeatedly annealing as brass work hardens.
If I had my heart set on a bell replacement, I would do a wet layup fiberglas bell. You will need a form to lay up on, but it doesn't have to withstand hammering. Auto designers do it with plywood[url]<LINK_TEXT text="https://sheetmaterialswholesale.co.uk/s ... d-class-2/">https://sheetmaterialswholesale.co.uk/sheet-materials/hardwood-plywood/poplar-core-plywood-class-2/</LINK_TEXT> and clay for prototypes. Some time ago I made a trombone bell form with styrofoam and masking tape. That first attempt was not very good, but with some practice and experimentation you could probably make one. If you had access to a lathe you could "turn" one easily out of soft wood or one of the harder waxes.
Then before using fiberglas, do a test run with papier mache. That was where I stopped. I did get a bell but it was frustratingly difficult to cover a flare. It's not a cone that flat pieces can "tile" to. Anyway, I would do a test layup with papier mache then proceed to a fiberglas construction. Caution: auto body repair kits are cheap but they use polyester resin instead of epoxy. That's not as strong and it is more of a health risk because of vapors. If I were ready to make a keeper I'd use one of the epoxy resins like boat builders and gliders use, like a West System.
</QUOTE>
Today we look to wood to replace concrete and steel in our buildings, because it is strong, easy to work with, and it has a much lower carbon footprint. But why stop there?
For 3 valve instruments often the best option is to graft in a new full cluster (all 3 valves with casings). Many makers used to do this. Blessing had a reputation for making valve clusters for other makers.
[/quote]
This.
IMO spinning a bell, particularly of that size, is not within amateur abilities or equipment.
Smaller bells are sometimes hand hammered successfully, but now you need to make a solid mandrel, and you'll be repeatedly annealing as brass work hardens.
If I had my heart set on a bell replacement, I would do a wet layup fiberglas bell. You will need a form to lay up on, but it doesn't have to withstand hammering. Auto designers do it with plywood
Then before using fiberglas, do a test run with papier mache. That was where I stopped. I did get a bell but it was frustratingly difficult to cover a flare. It's not a cone that flat pieces can "tile" to. Anyway, I would do a test layup with papier mache then proceed to a fiberglas construction. Caution: auto body repair kits are cheap but they use polyester resin instead of epoxy. That's not as strong and it is more of a health risk because of vapors. If I were ready to make a keeper I'd use one of the epoxy resins like boat builders and gliders use, like a West System.
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Today we look to wood to replace concrete and steel in our buildings, because it is strong, easy to work with, and it has a much lower carbon footprint. But why stop there?
- LeTromboniste
- Posts: 1634
- Joined: Apr 11, 2018
[quote="Aftess"]Today we look to wood to replace concrete and steel in our buildings, because it is strong, easy to work with, and it has a much lower carbon footprint. But why stop there?[/quote]
Wood deforms much easier than steel. A good friend and colleague of mine is also an instrument maker. I think he does or did use a wooden mandrel for one of his instrument models, but he said it doesn't last more than 10 bells, after which he needs to turn a new mandrel, which is time consuming. He also said after spinning, the bell gets stuck hard onto the wood and it can be tricky to remove it without damaging it.
Wood deforms much easier than steel. A good friend and colleague of mine is also an instrument maker. I think he does or did use a wooden mandrel for one of his instrument models, but he said it doesn't last more than 10 bells, after which he needs to turn a new mandrel, which is time consuming. He also said after spinning, the bell gets stuck hard onto the wood and it can be tricky to remove it without damaging it.