Converting Your Horn to Screw Bell

 Why a Screw Bell?

Soldering the male bell ring

Screw bell horns offer several advantages over fixed bell models. The most obvious is portability. The horn can be transported in a compact, easy to carry package that fits easily in a crowded bus or subway or in an airplane overhead compartment. Taking the bell off the horn also reduces damage caused by hard knocks or falls since the thin bell no longer has to bear the weight of the valve machine. The ring itself reinforces the bell at its weakest point.

A less obvious advantage is the ability to add different bell flares to the instrument. An old instrument can be rejuvenated with a new flare. Flares of different alloys, sizes, weights, or hardness, or with features such as garlands can be added as well. Since the flare has about 75% of the radiating surface of the instrument a change here can have a profound effect on the sound and feel of a horn.

What Kind of Ring?

We recommend Alexander and Engelbert Schmid screw rings. Alexander rings are often used in screw-bell conversions. They are strong and durable and are used when compatibility with Alexander, Lawson, Conn/King,  Holton, and Atkinson horns is desired. Many small makers (Lewis, Rauch, etc.) use Alexander compatible rings. Alexander rings fit small bell horns without modification. To fit larger bells they must be adjusted to fit the larger taper. Unless the inner diameter is changed to a standard size using replacement bells will result in a "step" where the bells join. Unless otherwise instructed, we fit Alexander rings on large bells to the Lawson dimension at that point to insure compatibility with Lawson flares. (The de-facto standard for large flares.)

Please be aware that several makers use rings that are "Alexander compatible". These copies may or may not fit other instruments with similar "compatible" rings. We use genuine manufacturer's parts only.

Cleaning up the bell flareWe recommend Engelbert Schmid bell rings. They are slightly lighter than Alex rings and allow compatibility with a wide range of Schmid bell flares. The unique design of the Schmid bell tapers makes it possible to use medium, wide, and extra-wide flares on the same instrument with no step at the ring. Schmid bells are readily available in the full range of sizes and alloys.

In addition to the rings listed above, we can obtain rings from Finke, Paxman, Yamaha, or any other currently active maker. The bell rings we use are genuine manufacturer's parts. They are not copies. Of course, we can custom make bell rings in any dimension. (We've made screw rings for everything from piccolo trumpets to tubas!) Custom rings are often used to replaced damaged or worn out rings on Geyers, C.F. Schmidts, and other classic instruments.

The Process

The first step in converting a horn to screw bell is the removal of the bell from the instrument. Any major dents are removed and the bell rim and throat are rounded up to accept the bell ring. Next, the lower (male) half of the ring is slid over the bell and soldered in place. Then the bell is cut and the flare is cleaned up.

The upper (female) half of the ring is then attached to the tail of the bell and finished. The last step is reinstallation of the tail to the horn and the trimming and refitting of the main bell brace. The tail and flare are polished and (if desired) relacquered.

There are other, less expensive ways to install a bell ring but the distortion of the bell entailed results in significant work-hardening of the metal with a strong chance of changing the sound. The cosmetic results are also often less than satisfactory.

Finishing the spoutOptions

Lacquer


We normally re lacquer all our repair work. We use a baked on epoxy lacquer finish unless otherwise requested.  We will re lacquer the entire bell tail and flare to minimize the "patched" look. 

Cases

We have a full range of screw bell horn cases from Cardo-case, T&M (Bags), and Pro-Tec, as well as our Brazilian-made Flight cases.

Time and Cost

We normally have the horn in the shop for two to four days but, if necessary, we can usually turn a horn around in one (long) day with an appointment. Please make an appointment at least a week in advance by email or by calling us at 978 823 0580. 

A screw bell conversion costs $675 ($625 for unlacquered horns). All our work is guaranteed. The cosmetic quality of your screw bell conversion will be equal to or greater than that of a factory screw bell installation. Naturally, custom made rings are priced individually, according to the complexity of the job.

 

Same Day Service

The finished product

 

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