Silicone molds for concrete: wet kilograms and a jacket

Don't pour wet concrete into an unsupported Shore 10A-20A skin. Hydrostatic load from a full cavity will balloon the walls, flatten stone texture, and throw finished thickness before the mix sets. The mold you want is a platinum RTV cavity (resin master to RTV casting mold, detail coat) sitting inside a rigid support, with a peel path for undercuts. RUUIPON has poured this stack in Bao'an since 2018. Prototype in 3-7 business days after CAD lock. MOQ 20 molds per design. This slug is the concrete job. The longer paver explainer is concrete and cement molds. Plaster chips differently: plaster. Architectural panels: architectural casting. LSR *parts* → ask us.

Wet mass first, Shore last

Write the filled kilograms, not the dry tile weight. A 400 x 400 x 40 mm paver in a wet mix is often in the 12-15 kg band. Soft RTV without a jacket sags about 0.5-1.5 mm at the unsupported edge. Design the jacket for the heaviest pour, including vibration. Raising Shore to stop sag is the wrong first move; add the mother mold.

Name max aggregate size. Stone scours thin letters. Budget a recast of the skin against the unsanded master.

When this concrete-slug advice does not apply

A tiny 100 mm sample tile you will cast twice can skip the jacket. Closed architectural panels may belong in rigid forms. Gypsum-only plaques: plaster page. Geometry can override quantity: one large wet vessel still needs a jacket even if you only want two molds. Planters that are hollow belong on planters and vessels.

If you only have photos, custom 3D modeling is USD $50 when that scope applies.

Concrete RFQ to copy

• Master: CNC, textured print, or physical sample
• Finished L x W x H and filled wet mass in kg
• Mix family and max aggregate size
• Open-back vs wrap-around rim
• Jacket material if you care
• Recast of the RTV skin: included or extra
• Custom 3D modeling: USD $50 when that scope applies
• Prototype + production (MOQ 20)

Send wet kilograms and undercut photos to contact ([email protected] / +86 135 3006 2969). Licheng Technology Industry Park, Xinhe Blvd, Shajing, Baoan.

Matched CTA: Send wet mass, mix, and undercut photos for a jacket-and-Shore review - not a generic free quote.

We would not recommend skipping the mother mold on large wet concrete

We would not recommend a one-piece unsupported glove for a paver measured in kilograms. We would not raise Shore A first to "make it stiffer." We would not pour a solid RTV block as a substitute for a skin-plus-jacket. We would not copy a worn, already-bellied sample as the new master. We would not quote LSR steel because you "might scale later."

RUUIPON Mold Structure Decision: flat open-back paver? open-back RTV skin. Locked rim? split or plug. Wet mass in kilograms? mother mold required.

Typical shop values

Reference values only. Confirm material-specific limits against the supplier’s technical data and agree project acceptance criteria before production.

FAQ

Do I need a mother mold for a concrete paver? If the pour is measured in kilograms, yes. Tiny sample tiles can skip it.

Can I just order a harder Shore instead of a jacket? Don't. A thick 25A wall still creeps under wet cement.

Will abrasive aggregate kill the mold? It will wear a thin letter. Name max stone size and budget a recast.

Is platinum shrink a problem for a 400 mm paver? Typical 0.1-0.3%. That's millimeters on a large tile. Lock the master oversize if OD is CTQ.

Does paying for the mold mean I own the jacket and master? Only if the PO says so. Tooling charge is not unrestricted ownership.