Founders & tuners of bronze bells
Cast flat.
Tuned true.
A bell leaves the mould a little below its note. Bronze comes off the inside on the tuning lathe until the nominal is exact — and because metal cannot be put back, every cut is weighed first. The sheet on the right is this month's tenor: five cuts, — of bell metal, — recovered.
Ring of eight for St. Agatha's, Covington · commissioned March 2026 · poured Thu 13 Aug · tuned 24–25 Sep · hung Fri 9 Oct
The charge
Seventy-eight parts copper, twenty-two tin.
Bell metal is a bronze-age arithmetic problem: 78% copper for stiffness, 22% tin for the strike. We buy cathode and ingot by the ton and charge the furnace against each casting — the pour, the returns, and the melt loss all on one line.
The ledger below is this ring's heat balance. Returns are the sprues, risers and flash that come back off the moulds; loss is what the furnace takes. Every row reconciles: bell + returns + loss = charge, and copper plus tin makes up the charge to the decimal. Total metal weighed out for the eight bells: — of bronze — — copper, — tin.
| Casting | Cast kg | Returns kg | Loss kg | Charge kg | Cu kg | Sn kg |
|---|
Audit. Rows reconcile by construction — charge = cast + returns + loss and Cu + Sn = charge on every line; the totals are sums of the printed figures. Melt loss held at 1.2% across all eight heats.
The ring
Eight bells, E♭ to E♭, weighed and corrected.
A ring of eight spans a major octave from the tenor. Each bell was cast deliberately flat of its nominal — you tune up, never down — then corrected on the lathe. The two right-hand columns are the whole story of this commission: what each bell weighed, and what came off.
| Bell | Nominal | Hz | Cast kg | lb | Cast ¢ flat | Removed g | Final ¢ |
|---|
Audit. Removed grams × response (§03) = the cast-flat correction on every line; the tenor's 1,839 g is the sum of the five cuts on the tuning sheet. Total struck weight: —.
The lathe
A bell is finished by subtraction.
Tuning is cutting, measured in grams and cents. Metal off the sound bow moves the nominal quickest; the waist least. Small bells answer faster than heavy ones — a gram off the treble is worth nearly five grams off the tenor — so the response is tabled per bell before the first cut is made.
The cuts run large to small. The first cut does the rough work, the last cut is a settle cut measured in single cents, and the tuner stops when the strobe reads 0.0 — never past it. The table below is this ring's response curve: cents gained per gram removed, and the metal each bell gave up to come true.
| Bell | Nominal | Cast kg | Response ¢/g | Removed g | Corrected ¢ |
|---|
Method. Response derived per bell as correction ÷ removal — it rises as bells get lighter, roughly as mass to the −0.8. Figures print to four decimals because the fourth one is the one that stops a tuner's hand.
“The old tenor had been fourteen cents flat since 1953. You could hear it every Sunday — a shade sour under the trebles. On the Friday it came true, and the whole tower rang a peal to try it.”E. Marchetti · Tower Captain, St. Agatha's, Covington · first ringing 11 Oct 2026
Consigned to re-melt
What we poured that did not ring.
Nine castings went out of this shop in 2026. Eight of them are in St. Agatha's tower. The ninth — a 92.6 kg Angelus bell for a school in Highland Heights — pinholed at the crown as it chilled, and no amount of fettle would make it honest. It went back to the furnace whole.
We print the re-melt rate on the front page because a foundry that never re-melts is a foundry that hangs its mistakes. A bell with a hidden flaw is a bill the buyer pays for thirty years. Ours reads: if a Crane & Hollis bell cracks within twenty-five years of its pour, we recast it free and pay the freight.
| Casting | Mass kg | Fault | Disposition |
|---|---|---|---|
| 26-107 · Angelus · 2026 | 92.6 | Pinholes at crown, chill tear | Consigned to re-melt — mass returned to the 2026 charges |
| 25-089 · School bell · 2025 | 74.2 | Slag inclusion in the waist | Re-melted; recast 25-104, hung at St. Bartholomew's |
| 24-201 · Chiming bell · 2024 | 158.9 | Chill tear at the sound bow | Re-melted; recast 24-214, hung at the courthouse |
| 2026: 9 poured | — | 8 hung, 1 re-melted | The re-melted mass reappears as returns in the year balance |
The tower
Fourteen shop weeks from pattern to peal.
Casting is a third of the commission. The bells must be fettled, drilled, tuned, fitted to headstocks and clappers, and hung in a frame that carries fourteen hundredweight of swinging bronze without shaking the tower apart. This is the shop card for one ring of eight.
| Weeks | Shop | Work |
|---|---|---|
| 1–2 | Pattern shop | Strickle and case built; core loam mixed and dried |
| 3–5 | Moulding floor | Moulds built in loam, dried slow over coke stoves |
| 6 | Furnace | The pour — Thursday 10:00, visitors on the gallery rail |
| 7–8 | Fettle bench | Castings cleaned; cannon holes drilled; first strobe reading |
| 9–10 | Tuning shop | Metal taken from the inside until each nominal reads 0.0 ¢ |
| 11 | Machine shop | Headstocks, gudgeons and clappers fitted; wheels spoked |
| 12–13 | The tower | Frame levelled; bells hung, stayed and rope-spliced |
| 14 | Handover | Ring-up with the tower band; sheet signed; keys to the tower door |
Metal cannot be put back.
Every cut is weighed before it is made, and every casting that will not come true goes back to the furnace — never up a tower. That is the whole discipline of this shop, and it has not changed since Ephraim Crane's first heat in 1911.