How do I weigh my wax model?

Use a digital kitchen scale. Weigh the complete wax model including sprues if already attached. For hollow wax shells, the weight is typically 60-80% less than a solid equivalent.

Why is bronze so much heavier than wax?

Bronze density is 8.8 g/cm³ compared to wax at 0.9 g/cm³ — nearly 10 times heavier. A 500 g wax model becomes approximately 4.9 kg in bronze. This significant weight difference affects handling, shipping and display.

How much does bronze cost in the UK?

Bronze ingot for art casting (silicon bronze / Everdur is the usual sculpture alloy; phosphor bronze is also used) costs roughly £12-20 per kg at retail in small quantities — a UK foundry supplier listed an 8.5 kg silicon-bronze ingot at £158.95 in mid-2026 (~£18.71/kg). Buying in bulk is cheaper. Either way the raw metal is a small fraction of the total casting cost, which is dominated by labour, shell building and finishing.

What is the total cost of bronze casting?

Professional bronze casting in the UK typically costs £30-60 per kg of finished bronze, all-inclusive. A 5 kg casting might cost £150-300. This includes shell building, burnout, pouring, fettling and basic patina.

Can I cast bronze myself?

Home bronze casting requires specialist equipment: a furnace reaching 1100°C, crucibles, investment materials and safety gear. Most artists use professional foundries. However, aluminium casting at lower temperatures is feasible for home workshops.

ArtCalcs

Bronze Weight Calculator — Wax to Bronze Conversion

Estimate the weight and cost of a bronze casting from wax model dimensions.

Wax Model Weight

Weigh the finished wax pattern (with sprues) on a digital scale — its 5-8 mm wall becomes the bronze wall

Shell Thickness

Investment shell build-up (6-10 coats, ~3-6 mm) — used only for the crating-weight estimate

Bronze Price per kg (optional)

Leave blank to skip cost estimate

How We Calculate This

How Bronze Weight Calculation Works

Bronze weight = (Wax weight ÷ Wax density) × Bronze density

In lost-wax casting the bronze occupies exactly the space the wax pattern held, so weighing the wax gives the true casting weight directly — no guessing at solid volume. The wax weight is divided by wax density (~0.9 g/cm³) to get the cast volume, then multiplied by bronze density (~8.8 g/cm³). Because the wax pattern is itself a hollow 5-8 mm shell (which becomes the 5-8 mm bronze wall), this volume-replacement method correctly captures hollow art bronze rather than overweighting it as a solid block. Bronze is roughly 9.8× heavier than the same volume of wax.

Default density is 8.8 g/cm³ (phosphor bronze). Silicon bronze (Everdur), the most common UK sculpture alloy, is a touch lighter at ~8.5-8.75 g/cm³ — adjust it under Advanced Options for a tighter figure.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before purchasing materials.