Bach bell stock gauges

[ithinknot]

Brass gauges: #24 = .020"
#23 = .0225"
#22 = .025"
#21 = .028"
#20 = .0.32"


The Peppy charts give the standard Mt Vernon thickness as #23 minus .0015, i.e. .021.

With the move to Elkhart, the standard stock becomes .025, and the 'wavy flower' pressure forming process is introduced.

Standard gold bells are heavier than yellow (.028?)

Star indicates lightweight. (LW yellow .0225, LW gold = standard yellow .025?)

H indicates heavy (introduced later? when? Does heavy yellow = standard gold, and heavy gold reaches ... .032??)



What's right/wrong/missing?

Enquiring minds don't really need to know, but are nonetheless interested...

[elmsandr]

Not sure about the hard and fast nature of this. My early Elkhart 50G (sn 9xxx) is the thinnest Bach flare I’ve ever had or seen.



Also, my Mt V 42 is thicker than my early 90s 42. I don’t have the sheet where I recorded measurements handy, or I’d give exact values. (I was working in a shop that had a lot of brass stock for stamping presses and great access to some really nice ball end micrometers for a while)

Cheers,
Andy

[bellend]

Yeah, I would take those with a pinch of salt if I were you.
Brasss is bought by weight and if there was a great deal on a particular gauge maybe for overstocking reasons or something, do you really think they would knock it back to stick to these spec's ?????
It is at the end of the day a money making enterprise pure and simple.

BellEnd

[ithinknot]

Not sure about the hard and fast nature of this.

Sure - and they never seem to have been particularly fussy about precise stamping after the fact - but however variable the end results, there must have been standard sheet specs at any given time.

Obviously in Mt V and before, you'd expect more 'specials' and experiments. I'm mostly wondering about Corp and later default practice.

[Thrawn22]

I think there is a design that was made on paper with exact specs, but put to practice in production models I'm sure cost, quality of the worker and other factors go into the variances that are prevalent in all horns.

I did get a Bach gold btass bell for it's weight and alloy, so you're assessment on gauge goes with my uninformed opinion.

[Kbiggs]

There is a lot of variation in the bell thickness. I believe it’s due partly to the density of the original material and the amount of work done to form the bell. If you start with the same stock, you can produce a thinner, more dense bell if you work it enough (in the wrong way!).

Having said that, of the 50 bells I’ve seen and played, the yellow bells tend to be thinner while the gold bells tend to be thicker. I’ve often wondered how a 50G* (star) bell would play, that is, something like the 42G*.

[Burgerbob]

I've found Bach bell thicknesses to be, surprise surprise, pretty much random. Some of my corp bells have been thin (like the one I use currently on bass), some have been thick (a couple 42 bells). Some L bells are ridiculously thin, some are thick. I have played a 50T3LGH that I think was probably a half inch thick. Worst Bach I have ever played.

My first cut bell was an '80s 50B that was quite thick- great sounding bell but it was made a bit too heavy with the cut ring.

I'm sure there's some generalities you could apply to each era, but as with most things Bach, there are hundreds of exceptions, always.

[ithinknot]

random

Sure. All the yellow Corps I've owned or played have been noticably different. But I don't necessarily imagine they started from radically different sheet stock, and they were closer than my 80s LT8G's bell, which feels a gauge or more thicker (and, of course, didn't get a G stamp...). 'LGH' does sound pretty awful even just as an idea.

But my question is specifically about the starting point, not the varied end results. To be sure, 1 piece bells definitely have more scope for production inconsistency, and doubtless some of Bach's procedures and staffing didn't necessarily, errr, minimize that potential.

I would be really interested to know where the 'gold is thicker' default came from. I suppose anyone who really knows is either dead, professionally disinclined to talk, or both.

I could imagine a specific logic: "nickel LT slides and gold bells seem to be a successful tonal combination for a lot of people, but let's increase the gold bell weight a bit to stop things getting too frisky/too lightweight overall"
... or they were already making the gold bells heavier, which led people to favor the LT slide combo to stop everything getting too heavy/slow overall
... or maybe it's just a question of which gauge of C240 80/20 they could order at some formative point.

[Matt K]

I’m going to guess that people who want gold bells want something “darker” and so they also made them slightly heavier to help with that. Possibly in combination with availability of gold brass sheet metal and or pricing

[Thrawn22]

I’m going to guess that people who want gold bells want something “darker” and so they also made them slightly heavier to help with that. Possibly in combination with availability of gold brass sheet metal and or pricing

Playing my 36G bell yesterday i noticed that hit was thicker and a bit heavier than most bells I've used.

[Crazy4Tbone86]

I am going to contradict the notion that the Elkhart Bach gold brass bells are thicker than the yellow brass bells. I have four gold brass bells ranging from mid 70s to early 90s. One is on the thick side…….bell thickness is about .026 -.027 inch. The other three are actually slightly thinner than the standard 22 gauge (.025 inch) in the bell flare area. Two 42s average about .023 when I measure them (it is not consistent). My 50 gold bell averages in .022 range. Again, it is not consistent and can vary by 1 or 2 thousandths. None of these bells are stamped with the star (indicating lightweight bell). Also, none of these bell appear to have any excessive buffing in their histories.

I always assumed that these “thinner” bells just started as 22-gauge sheet metal and were thinned slightly in the one-piece bell spinning process. One piece bells are usually thinner in the bell flare and I have always measured bell thickness about 1/2 to 1 inch away from the rim. I suppose, if I ever pull these horns apart, I should measure them at the bell stem in order to get a closer determination of what gauge was used.

I think another consideration is that not every gauge in every alloy has been available at every point in history. I’m sure every instrument manufacturer has struggled to get a specific gauge of a desired metal and might have “settled” for a different gauge because of cost and/or availability.

[ithinknot]

I have always measured bell thickness about 1/2 to 1 inch away from the rim. I suppose, if I ever pull these horns apart, I should measure them at the bell stem in order to get a closer determination of what gauge was used.

Yes, the flare edge will show the most variation. Thanks for the numbers - do you have some yellow measurements for comparison (or - cue Shirley Bassey - do you love only gold)?

[Crazy4Tbone86]

I have some yellow Bach bells as well, only three of them are non-H (heavy gauge). Two of the non-H bells are in the .023 average…..I am assuming those started as 22 gauge (.025 inch). The other yellow bell is a late 70s 42 that measures at .026…….I am assuming that started as a 21 gauge (.028 inch).

You know, I am starting to wonder if I need to spend my life on more useful things. I’m pretty sure that in the time I have used to gather a catalog such useless brass instrument information, I probably could have learned a new language or learned how to rebuild a car engine!

[bellend]

I have always measured bell thickness about 1/2 to 1 inch away from the rim. I suppose, if I ever pull these horns apart, I should measure them at the bell stem in order to get a closer determination of what gauge was used.

Yes, the flare edge will show the most variation. Thanks for the numbers - do you have some yellow measurements for comparison (or - cue Shirley Bassey - do you love only gold)?

Not really sure why you say that?
The flare edge will emain fairly close to the original gauge as it really doesn't get worked that much during the manufacturing process. The attached photo shows tht majority of the work is in breaking the back of the bell further back from the rim in order to bring the side oposite the brazed seam out in to a rough flare shape.
Bach do this with some sort of pressurized bladder to distend the material but still not the flare edgeas seen here.




This video shows the hand working employed by Yamaha around the 4.00 mark.


BellEnd

[ithinknot]

Not really sure why you say that?
The flare edge will emain fairly close to the original gauge as it really doesn't get worked that much during the manufacturing process. The attached photo shows tht majority of the work is in breaking the back of the bell further back from the rim in order to bring the side oposite the brazed seam out in to a rough flare shape.
Bach do this with some sort of pressurized bladder to distend the material but still not the flare edgeas seen here.

Granted, the 3D stamped starting blank Bach uses seems to leave relatively little need to push the flare edge out to final diameter. A more traditional process might involve more rounds of inside spinning and subsequent work on the mandrel to reach final diameter (for example, Bernd Sandner).

I guess it's always a choice controlled by your starting sheet pattern - a less 'winged' pattern gives you less work at the back breaking stage, but then takes more spinning out to final diameter, with more thinning towards the edge, whereas a larger pattern might be wide enough to require very little spinning out and exhibit no thinning, but would take a lot more work to break the back.

(But I was mostly just talking about measuring finished bells and agreeing with Crazy4Tbone86 that if you had the option of measuring an unmounted bell at the stem then that area would have 'been through the least' in the manufacturing process.)

[bellend]

Not really sure why you say that?
The flare edge will emain fairly close to the original gauge as it really doesn't get worked that much during the manufacturing process. The attached photo shows tht majority of the work is in breaking the back of the bell further back from the rim in order to bring the side oposite the brazed seam out in to a rough flare shape.
Bach do this with some sort of pressurized bladder to distend the material but still not the flare edgeas seen here.

Granted, the 3D stamped starting blank Bach uses seems to leave relatively little need to push the flare edge out to final diameter. A more traditional process might involve more rounds of inside spinning and subsequent work on the mandrel to reach final diameter (for example, Bernd Sandner).

I guess it's always a choice controlled by your starting sheet pattern - a less 'winged' pattern gives you less work at the back breaking stage, but then takes more spinning out to final diameter, with more thinning towards the edge, whereas a larger pattern might be wide enough to require very little spinning out and exhibit no thinning, but would take a lot more work to break the back.

(But I was mostly just talking about measuring finished bells and agreeing with Crazy4Tbone86 that if you had the option of measuring an unmounted bell at the stem then that area would have 'been through the least' in the manufacturing process.)

I don't think that spinning out the blank ( from the inside) is that commonly done, I have seen it only once from a German ( I think)French horn maker. Even when it's beaten out from the inside most of the movement happens in the throat out into the flare but not to the end of it.

I would agree with you that that the best place to measure the wall thickness of a piece bell would be at the end of the stem.
From memory I don't remeber ever really measuring Bach bells as appart from two expeperimental one pieces,
I made two piece bells. I know the stem on an Elkhart 8/88H is in the 0.3/0.35 mm region i.e. pretty thin

BellEnd

[brassmedic]

I am going to contradict the notion that the Elkhart Bach gold brass bells are thicker than the yellow brass bells. I have four gold brass bells ranging from mid 70s to early 90s. One is on the thick side…….bell thickness is about .026 -.027 inch. The other three are actually slightly thinner than the standard 22 gauge (.025 inch) in the bell flare area. Two 42s average about .023 when I measure them (it is not consistent). My 50 gold bell averages in .022 range. Again, it is not consistent and can vary by 1 or 2 thousandths. None of these bells are stamped with the star (indicating lightweight bell). Also, none of these bell appear to have any excessive buffing in their histories.

I always assumed that these “thinner” bells just started as 22-gauge sheet metal and were thinned slightly in the one-piece bell spinning process. One piece bells are usually thinner in the bell flare and I have always measured bell thickness about 1/2 to 1 inch away from the rim. I suppose, if I ever pull these horns apart, I should measure them at the bell stem in order to get a closer determination of what gauge was used.

I think another consideration is that not every gauge in every alloy has been available at every point in history. I’m sure every instrument manufacturer has struggled to get a specific gauge of a desired metal and might have “settled” for a different gauge because of cost and/or availability.

That's odd. I measured a few Bach bells I have, and they are nowhere near that thick. A yellow brass 42 I bought about 8? years ago is around .012" at the flare (and I recall some Mt. Vernon bells that I measured awhile back seemed to be in that range too). I have a 42G bell from mid 1990s, which is very inconsistent, ranging from .013 to .02 right around the seam. I have a 36G which ranges from .013 to .017. I have never measured a Bach trombone bell to be more than .02 at the flare. Too small a sample, I think, but the gold brass ones do seem to be very slightly thicker than the yellow brass.

[Crazy4Tbone86]

Brad,
That actually makes sense to me. I have had some Bach bells come through that I measured in the .013 - .015 range near the rim. However, many of those thinner bells did not play that well for me. I tend to favor bells that hold together easily in the forte and louder range. It’s one of the first things I test when trying horns and my collection has gravitated towards the thicker bells.

My primary bass trombone bell for the past year has been an Edwards 987CF, which is a 20 gauge yellow brass bell. Many players find that particular bell unplayable because it is so heavy, but I really like it.