Silicone molds for plaster: brittle demold, soft skin
Plaster and gypsum are brittle when you demold them. The mold has to flex around a hanger island or a thin leaf so the casting doesn't carry the peel load. That's why plaster tools are usually Shore 10A-20A platinum RTV with a planned split, not a stiff 40A block "so it holds detail." Wet gypsum still has mass: a large open-back plaque will sag 0.5-1.5 mm without a jacket, and a full-3D figure will tear a one-piece glove. RUUIPON pours these RTV tools in Bao'an since 2018: photos, sketch, or CAD, then a 3D-printed pattern, often a temporary silicone flip, a resin production mother, then batch RTV. Prototype in 3-7 business days after CAD lock. MOQ 20 pcs/design. This slug is the plaster job. The longer explainer is plaster and gypsum molds. Figurines: figurine molds. Concrete abrasion: concrete.
Open-back plaque vs full-3D bust
Open-back wall plaques often peel as one piece if relief is modest. Hanger holes, undercut letters, and wrap-around frames do not. Full-3D busts need the seam off the face, keys, maybe a plug. Don't ask a green plaster finger to survive a one-piece strip. See split lines and mother mold.
Raising Shore to "protect detail" is backwards: stiffer rubber loads the plaster.
When this plaster-slug advice does not apply
Abrasive cement with large aggregate is the concrete page. Resin can take a yank plaster cannot. LSR *parts* → ask us. A tiny sample tile can skip the jacket. Geometry can override quantity: one bust still needs keys.
If you only have photos, custom 3D modeling is USD $50 when that scope applies.
Plaster RFQ to copy
- Process: platinum RTV plaster cavity
- Open-back vs full-3D; filled wet mass
- Hanger holes, thin leaves, logo depth
- Jacket material if you care
- Custom 3D modeling: USD $50 when that scope applies
- Prototype full-weight pour, then MOQ 20 pcs/design
Send master photos, wet kilograms, and the one failure you most want to avoid to contact ([email protected] / +86 135 3006 2969). Licheng Technology Industry Park, Xinhe Blvd, Shajing, Baoan.
Matched CTA: Send wet gypsum mass and hanger/leaf photos for a peel-and-jacket review - not a 40A "detail" quote.
We would not recommend a 40A block so the plaster "holds detail"
We would not recommend a one-piece glove for a full-3D bust. We would not skip the jacket on a kilogram plaque. We would not copy a resin-figurine yank onto green plaster. We would not hang 177.2600 on a plaster tool.
RUUIPON Mold Structure Decision: open-back plaque if relief peels. Locked hanger or bust? split/plug. Wet kilograms? mother mold.
- Flat open-back plaque? - no bust/wrap -> Deep undercuts?
- Deep undercuts? - peels safely -> Open-back RTV skin
- Deep undercuts? - locked -> Two-part / plug
- Wet mass in kilograms? - tiny tile -> Open-back RTV skin
- Two-part / plug -> Mother mold
- Open-back RTV skin -> Wet mass in kilograms?
Typical shop values
Reference values only. Confirm material-specific limits against the supplier’s technical data and agree project acceptance criteria before production.
| Item | Typical shop value |
|---|---|
| MOQ | 20 pcs/design after sample approval |
| Custom 3D modeling | USD $50 when that scope applies |
| Prototype | 3-7 business days after CAD lock |
| Mix | Platinum 1:1 or 10:1; vacuum degas |
| Cavity Shore | 10A-20A platinum; jacket behind it |
| Platinum shrink | About 0.1-0.3% after full cure |
| Loaded-edge sag without a jacket | About 0.5-1.5 mm |
FAQ
Do I need a mother mold for a plaster plaque? If the pour is measured in kilograms, yes. Tiny sample tiles can skip it.
Can I just order a harder Shore? Don't. Stiffer rubber chips plaster. Add the jacket; keep the peel.
Will a hanger hole break out? If the island is thin. Draft the pin or drill after.
Is platinum shrink a problem? Typical 0.1-0.3%. Lock the master oversize if a hole is CTQ.
How fast is a prototype? 3-7 business days after CAD lock. Pour full weight.