RTV Silicone Molding: What This Shop Actually Pours

RTV silicone molding on this site is how we copy a master into a flexible cavity you dump into. If you're buying a tool, the sequence is master inspection, mold box, A/B platinum (1:1 or 10:1, tin only when the job calls for it), vacuum until the foam collapses, keys, jacket if the dump is wet or the Shore is 10A-20A, then recast when the skin wears. That is the object. It is not an LSR cold-runner and not HCR compression of a silicone *part*.

RUUIPON has poured those cavities in Bao'an, Shenzhen, since 2018 (Licheng Technology Industry Park, Xinhe Blvd, Shajing). Custom/simple 3D modeling is USD $50 when that scope applies. Prototype is 3-7 business days after CAD lock. Production MOQ is 20 pieces per design after sample approval. Steel/LSR *parts* belong at wydsilicone.com. Process gates sit in the process catalog.

What RTV molding is on the bench

1. Master: CNC, finished print, or a physical sample you own. Measure it before A/B. See master options.
2. Box and split: open-back if the back is flat and the part can peel; keyed two-part, plug, or inner core if it cannot.
3. Mix and vacuum: weigh A/B to the grade ratio; degas until the foam collapses so pits are not your logo - vacuum platinum.
4. Pour, cure, pull the master, check keys.
5. Dump the real material on the prototype. Water is the wrong viscosity.
6. Multiply to MOQ 20 after a written pass/fail.

Don't call this "LIM" or "injection molding." Those nouns belong on a parts RFQ.

Common mix-up: RTV molding as a cheap LSR line

Buyers paste an RTV cavity quote next to an LSR spatula bid and pick the lower number. One ships a tray you pour pectin into. The other ships a vulcanized article. Shrink, tool, and factory are different (platinum RTV ~0.1-0.3%; LSR ~2-3% typical shop bands). See RTV vs HTV.

What this process is for (and what it isn't)

Use RTV molding when you need a recastable cavity, organic peel, a moving CAD, or a food/craft dump (pectin, chocolate, resin, wax, soap, plaster, concrete). Skip it when the carton is thousands of identical silicone *parts* or a high-volume steel gummy *part* tool.

Geometry can override quantity: a one-off resin hook still needs a split; 10,000 LSR spatulas do not.

Typical shop values

Caption these as typical shop values, not a named PO.

Failure: mixing A/B in open air, then blaming Shore

Symptom: Pits on the logo face; sticky tin sheet at restock 40; a "molding" quote that lists flash land and cold-runner.

Confirm: Was the pour vacuum-degassed? Is the quote an RTV cavity or a parts tool? Did anyone dump the real chemistry, not water?

Fix: Name the object. Vacuum platinum for production sheets. Recast against the living master. Don't raise Shore A to hide bubbles.

Worked example: 12-cavity 18 mm bear, pectin

CAD lock of cavity map and 0.4 mm recessed brand, CNC/print master, platinum 10A-20A skin, jacket so edge sag doesn't push outer-row grams 3-6% heavy, vacuum degas, prototype dump in pectin 3-7 days after lock, then MOQ 20. Custom 3D was USD $50 because the brand art was not a mold-ready STEP. An LSR "same bear" quote would have built the wrong factory.

What to ask when you're buying RTV molding

• Does this PI deliver a cavity I pour into, or a molded silicone part?
• Master type, split/keys, jacket yes/no, recast terms?
• Pour chemistry and peak °C before Shore?
• Food-contact: 21 CFR 177.2600 extraction and/or LFGB on this recast?
• Who keeps the master after the tooling charge? That charge is not unrestricted ownership.

When this page is the wrong route

If you already know you need a split, open split mold or split lines and keys. If you need a jacket, open mother mold. If you need thousands of vulcanized parts, don't use this URL to reverse-engineer a pour cell - use WYD. A catalog ice sheet that already matches is also the wrong spend.

Related: capabilities, services, process catalog, contact.

RFQ: RTV molding object first

Copy this.

Object: RTV cavity (not LSR/HCR part) Dump material + peak °C: Grams or cavity size (mm): Master: STEP / sample / photos+scale Split: open-back / keyed two-part / plug / core / shop to mark Jacket: yes / no / shop to mark Food-contact: 177.2600 / LFGB / craft-only 3D modeling needed? ($50 when that scope applies) yes/no Prototype then MOQ 20 per design Who keeps master / jacket / CAD:

Send STEP, pour material, and quantity to contact - [email protected] · +86 135 3006 2969. Don't hit a generic free-quote button.

We would not recommend calling this LSR molding

We would not recommend quoting RTV molding from a three-field form. We would not treat a tin hobby kit as the production sheet for sticky pectin or epoxy heat. We would not skip vacuum on a clear-resin or chocolate-logo face. We would not pay for a pretty one-piece master when the part cannot leave.

RUUIPON Mold Structure Decision:

flowchart TD
  O[What ships?] -->|vulcanized silicone part| WYD[WYD: HCR or LSR + cold-runner]
  O -->|cavity you pour into| F[Flat back?]
  F -->|yes| OB[Open-back RTV]
  F -->|no| U[Deep undercuts?]
  U -->|silicone can peel safely| OB
  U -->|cannot peel| S[Two-part / plug / inner core]
  W[Large wet dump or Shore 10A-20A?] -->|yes| M[Jacket / mother mold]
  OB --> P[CAD lock then 3-7 day prototype]
  S --> P
  M --> P
  P --> Q[MOQ 20 after sample approval]

FAQ

Is RTV molding the same as making silicone parts? No. We pour a cavity you dump into. Molded silicone *parts* (HCR compression, LSR injection) are a WYD quote.

Do you vacuum every pour? Production sheets that see clear resin, shallow logos, or sticky pectin should be vacuum-degassed until the foam collapses. A tin craft kit is not that sheet.

What's the prototype clock? 3-7 business days after CAD lock - not after the first WhatsApp photo. Production MOQ is 20 per design after approval.

Is custom 3D always $50? USD $50 when that simple/custom modeling scope applies. Complex organic rebuilds are scoped before anyone invoices.

Where is the shop? Bao'an, Shenzhen, since 2018: Licheng Technology Industry Park, Xinhe Blvd, Shajing. [email protected] · +86 135 3006 2969.