Vulcanized vs Platinum RTV Jewelry Wax Molds | RUUIPON

Vulcanized jewelry rubber is a heat-and-pressure pack around a metal master, cut by a jeweler, run in a wax injector at pressures and durometers a platinum RTV block will not copy. Platinum RTV is a room-temperature pour around a sealed master, keys if two-part, mix 1:1 or 10:1, vacuum, shrink typically about 0.1–0.3%. We pour the RTV path in Bao'an. We would not quote a vulcanizer as if it were our flask, and we would not tell a high-pressure injector shop to "just use our 20A glove." This page is the *fork* — when RTV is enough for a wax dump, and when you need a jewelry-tooling house instead. The how-to of sprues on an RTV jewelry tool lives on the lost-wax RTV page; we will not clone it here.

RUUIPON, Xinhe Blvd, Shajing, since 2018. Prototype is 3–7 business days after CAD lock. Production is MOQ 20 pieces per design. Simple 3D is USD $50 when that CAD scope applies. Steel/LSR *parts*: wydsilicone.com. RTV jewelry how-to: lost-wax RTV. Resin (no burnout): jewelry resin.

Does not apply when the dump is chocolate "jewelry," UV charms with no metal step, or an LSR watch strap. We would not put a 177.2600 pack on a wax-injector PO. Sulfur in some carving waxes can inhibit platinum — coupon first.

What the vulcanizer is for

A vulcanized mold is packed uncured rubber (often natural or a jewelry-specific compound), squeezed and heated around a metal model, then cut. The resulting block is firm, cut-friendly, and built for repeated wax injection at a jeweler's pressure band. Detail on a signet face can be excellent because the pack is dense. The shop that owns the vulcanizer also owns the cut skill. That is not our RTV flask.

RTV wins when you do not have a vulcanizer, when the master is a sealed SLA you do not want to heat-pack, when volume is a short platinum run (MOQ 20 / design), or when you pour or inject wax at a milder band. RTV loses when the injector will blow a 20A cavity, when the shop's SOP is vulcanized-only, or when you need a cut-pack workflow your bench already runs.

Durometer: jewelry vulcanized blocks often sit firmer than a 10A–20A food skin. Copying a 10A gummy Shore onto a ring shank is how the wax ovales. We would not spec 10A as a default jewelry RTV just because our food trays use it.

The photo that would prove the fork: injector gauge in frame, RTV split vs a cut vulcanized block, wax sprue on a hidden land. A gold ring on velvet proves neither tool.

flowchart TD
  A[Wax dump for burnout] --> B{Shop has a vulcanizer + cut SOP?}
  B -->|yes, high-pressure injector| C[Jewelry-tooling house — not our flask]
  B -->|no, or sealed SLA master| D[Platinum RTV path]
  D --> E[Coupon the wax for sulfur]
  E --> F[Keys, sprue, vents — see lost-wax RTV page]
  F --> G[1:1 or 10:1, vacuum, CAD lock]

Masters that cannot go in a vulcanizer

SLA and FDM masters generally do not want vulcanizer heat and pack. That is a common reason buyers land on RTV. Seal and slug those prints. Metal masters can go either way; the injector SOP then decides.

Tin RTV is a named craft choice some jewelers still like for dirty masters. We would not silently substitute tin on a platinum shrink number, and we would not use tin as a food workaround.

ISO 3302-1 M2 is a rubber class on the wax article if you spec it. It is not "jewelry precision" and not a vulcanizer spec.

CAD lock on RTV jewelry includes sprue OD and vent path. The $50 3D, when that scope applies, is the master/shut, not a vulcanizer program.

Ownership also splits. A vulcanized cut-pack at a jewelry house is their process knowledge in the cut. An RTV block we poured is still tooling-charge-not-unrestricted-ownership of our CAD and flask. Write who keeps the sealed SLA and who may recast. We will not archive a vulcanizer program we do not run.

Failure: RTV blown out on a jewelry injector

Symptom: flash all over the split, distorted shank, keys walked.

Cause: injector pressure and temperature band from a vulcanized SOP, applied to a 20A platinum block without a jacket or a firmer grade.

Confirm: injector gauge vs what you told us. A short-shot at lower pressure that fills clean is the clue.

Fix: lower pressure, firmer RTV grade, jacket/clamp, or go to a vulcanized house. Do not just "add Shore" without naming the injector.

Typical shop values

Caption: typical shop values, not a named PO.

Forks we would not blur

We would not recommend RTV as a drop-in for a vulcanized cut-pack SOP.

We would not recommend vulcanizer heat on an SLA master.

We would not recommend a 10A food glove as a ring-shank default.

We would not recommend a food pack on wax tools.

We would not recommend cloning the sprue essay from 288 onto this fork page as the whole article.

Worked example: signet, SLA master, injector from a vulcanized SOP

Signet, 18 mm, sealed SLA, buyer ran their usual injector pressure into a 20A RTV split. Flash and a fat shank. We recast a firmer platinum 1:1 block, added a clamp jacket, they dropped pressure until a short-shot filled. Prototype 3–7 business days after CAD lock of the firmer tool. $50 CAD applied because the signet face depth was not in the STL. Production MOQ 20 of that design. Vulcanizer stayed at their other vendor for metal-master SKUs.

Mix-up: "silicone jewelry mold" means one material

Vulcanized rubber and platinum RTV are different tools. Related: lost-wax RTV, contact.

What to ask when you're buying the fork

• Injector pressure/temp band you actually run?
• Master: metal (vulcanizer-capable) or SLA (RTV-likely)?
• Dump is wax for burnout, not UV resin?
• Sulfur wax coupon done?
• After lock, 3–7 business days, then MOQ 20 / design?

RFQ copy-pack — vulcanized vs RTV

Paste into [email protected]:

Object: platinum RTV wax tool, not a vulcanizer pack, not LSR Master: metal / sealed SLA Injector: pressure and °C, or pour-in wax Dump: wax for burnout File: STEP / STL / photos with a millimetre scale CAD: mold-ready OR USD $50 3D if that scope applies Prototype 3–7 business days after CAD lock, then MOQ 20 per design Who keeps the master

Send injector band and master family, not "jewelry mold." We will not pretend to be a vulcanizer — not a blank quote request. Phone +86 135 3006 2969. Xinhe Blvd, Shajing, Bao'an. Shop since 2018.

FAQ

Can platinum RTV replace a vulcanized jewelry mold? Sometimes, at milder injection or pour-in wax, especially with an SLA master. It is not a drop-in for a high-pressure cut-pack SOP.

Why did my RTV flash on the injector? Pressure and a soft cavity. Lower the gauge, firm the grade, clamp, or go vulcanized.

Will you vulcanize my metal master? No. We pour platinum RTV. A jewelry-tooling house owns the vulcanizer.

Is shrink the same? Platinum RTV is typically about 0.1–0.3% after full cure. Vulcanized compounds are a different family. Do not mix the numbers.

What's the clock if I pick RTV? 3–7 business days after CAD lock. USD $50 when we must model. MOQ 20 per design.