How much resin for spheres
Spheres, paperweights and domes are the molds that fool people most: they look small and swallow far more resin than a flat piece. A closed mold also fills in a single pour, so running short cannot be fixed mid-pour. Here are the grams by diameter, which resin survives that mass and how to pour bubble-free.
Resin per sphere or dome
| Piece | 1 pc | Set of 3 | Set of 6 |
|---|---|---|---|
| Sphere Ø3 cm | 17 g | 51 g | 102 g |
| Sphere Ø5 cm | 79 g | 237 g | 474 g |
| Sphere Ø6 cm | 137 g | 411 g | 822 g |
| Dome Ø8 cm | 162 g | 486 g | 972 g |
| Dome Ø10 cm | 317 g | 951 g | 1902 g |
| Dome Ø12 cm | 547 g | 1641 g | 3282 g |
How to calculate resin for a sphere
The volume of a sphere is 4/3 × π × radius³; a dome is half that. For a 6 cm sphere: 4/3 × π × 3³ ≈ 113 cm³, which at deep-pour density (~1.10 g/ml) is about 124 g of mix, 137 g with the 10 % margin. The table below is computed with the same engine as the calculator.
Which resin for a closed mold
A sphere mold fills in one go: you cannot pour in layers. That concentrated mass builds up heat, so you need a slow-curing deep pour like Artline Wood PRO, rated up to 6 cm per pour. Above a Ø6 cm solid sphere there is no safe single pour: switch to a dome (up to Ø12 cm) or a smaller diameter.
Pouring and bubbles
Pour in a thin stream through the mold opening, from high up: the stream stretches and breaks bubbles. Let the mix rest for 5 minutes before pouring and do not speed up the cure with heat — inside a spherical mass it heats up on its own. Demold at 48-72 hours, not earlier.
Example: 6 cm sphere
- Diameter
- 6 cm
- Volume
- ≈ 113 cm³
- Mix (+10 %)
- ≈ 137 g
- Resin
- deep pour, single pour
- Demold
- 48-72 h
Note: A 3 cm sphere takes just 17 g: the cube of the diameter rules. Run the numbers before buying.
Want the exact amount for your piece, with the A:B ratio and layer plan?
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Frequently asked questions
How much resin do I need for a 5 cm sphere?
About 79 g of mix with the 10 % margin included. A 3 cm one takes 17 g and a 6 cm one 137 g: volume grows with the cube of the diameter, not linearly.
Can I make a sphere with regular coating resin?
Not a good idea except at very small diameters. A closed mold fills in one pour and coating resin builds up too much heat in that mass: it yellows, smokes or cracks. Use a slow-curing deep pour.
Why did my sphere crack or overheat while curing?
Concentrated mass + resin that cures too fast. A sphere traps heat at its core. Use deep pour, do not warm the mold and do not exceed the diameter your resin allows per pour (6 cm for a typical deep pour).