Silicone molds for epoxy resin: inhibition, exotherm, and gloss

Epoxy resin copies the master, including a lock. A slow pot life lets you vent a thick pour; a hot exotherm in a deep block cooks the RTV sooner than a thin coaster. Don't assume platinum is compatible with every epoxy - run a coupon on a scrap of the same skin. RUUIPON pours epoxy-casting RTV tools in Bao'an since 2018: resin master to RTV casting mold. Typical cavity Shore 10A-20A for undercut peel, jacket for size. Prototype in 3-7 business days after CAD lock. MOQ 20 pcs/design. These are not food-contact trays; don't hang 21 CFR 177.2600 on an epoxy skin. The resin hub is custom silicone resin molds. Short pot life belongs on PU resin. Small holes: jewelry resin.

Compatibility before a full box

Send epoxy brand/family if known, max casting thickness, gloss vs matte, undercuts, and whether you vacuum or pressure-cast the *resin*. A dirty SLA master inhibits platinum. Barrier-coat. Master finish copies forever - master models.

High-point vents and a sensible gate still matter even with a long pot life. Air in a jewelry hole is a different page.

Jacket vs Shore

A 180 mm solid figure still bulges a soft skin. Unsupported sag about 0.5-1.5 mm is the conventional tray-scale number. Don't jump to 40A to "resist heat" - you'll load the undercut and still need a mother mold.

When this epoxy advice does not apply

PU with a 3-minute pot life is not this vent plan. Food dumps are food pages. LSR/HCR *parts* → an HTV product RFQ here. A one-off coaster can skip production keys. Geometry can override quantity: a closed undercut still needs a split at 30 casts.

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

Epoxy RFQ to copy

Process: platinum RTV (craft - not food)
Epoxy family; max thickness / exotherm notes
Coupon compatibility: yes
Gloss or matte master
Split / plug / jacket
Custom 3D modeling: USD $50 when that scope applies
Prototype with real epoxy, then MOQ 20 pcs/design

Send chemistry, thickness, and the master to contact ([email protected] / +86 135 3006 2969). Licheng Technology Industry Park, Xinhe Blvd, Shajing, Baoan.

Matched CTA: Send epoxy family, max thickness, and a compatibility coupon request - not a generic free quote.

We would not recommend a food-contact claim on an epoxy skin. We would not raise Shore A first to hide a missing jacket. We would not copy a 3-minute PU vent plan onto a slow epoxy. We would not sand the master after you like the gloss.

RUUIPON Mold Structure Decision: open-back if draft peels. Locked undercut? split/plug. Thick hot pour? jacket plus vents. Coupon before the full box.

Coupon compatible? - no -> Barrier / different RTV / different epoxy
Coupon compatible? - yes -> Undercut peels?
Undercut peels? - no -> Split / plug
Undercut peels? - yes -> Thick section / sag?
Thick section / sag? - yes -> Jacket + high-point vents
Thick section / sag? - no -> Prototype full pour
Split / plug -> Thick section / sag?
Jacket + high-point vents -> Prototype full pour

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 peel; jacket for size
Platinum shrink	About 0.1-0.3% after full cure
Loaded-edge sag without a jacket	About 0.5-1.5 mm
Food docs	Do not apply unless the cavity is a food dump

FAQ

Will every epoxy cure against platinum RTV? No. Coupon first. Inhibition is a master-prep and chemistry issue.

Does a longer pot life mean I can skip vents? No. Air still traps. High-point vents still matter.

Is this food-grade? Not by default. Epoxy tools are craft cavities.

How fast is a prototype? 3-7 business days after CAD lock. Pour the real epoxy.

When is PU a different quote? When pot life is minutes, not hours. Use the PU page.