Cure Chemistry · Condensation Cure
Tin Cured Silicone Rubber
Condensation-cure RTV-2 systems crosslink with a tin catalyst. They cure dependably against nearly any clean surface, which makes them the general-purpose workhorse of mold making.
How it cures
Tin cure silicone uses a tin catalyst and a moisture-driven condensation reaction to crosslink. It releases a small amount of alcohol as it cures, which evaporates and causes slight shrinkage over time.
Its strength is tolerance. Tin systems cure reliably against nearly any clean surface, including many that inhibit platinum systems, so surface preparation is simpler and failed pours are rare.
Cured tin silicone slowly reverts as the catalyst ages, so molds have a working life measured in years rather than decades. For most production runs and prototyping, that life is more than enough.
Strengths and trade-offs
- Shrinkage
- Slight, over time
- Contaminant tolerance
- High
- Cure byproduct
- Alcohol (evaporates)
- Relative cost
- Lower
- Inhibition sensitivity
- Rarely inhibited
- Mold life
- Good working life
Best for
- General-purpose mold making
- Prototyping and short production runs
- Casting concrete, plaster, wax, and resins
- Surfaces that inhibit platinum systems
General guidance. Confirm fit with our team for your application.
Choosing between the two
Need near-zero shrinkage, the tightest tolerances, or maximum mold life? Platinum cure is the precision choice.
Tin cure products
| SKU | Product | Cure | Shore A (7 day) | Mixed viscosity (cps) |
|---|---|---|---|---|
| GI-1000 | High-tear tin-cure RTV-2 mold making silicone | Tin | 32 | 30,000–45,000 |
| GI-1032 | Medium-durometer tin-cure RTV-2 case mold silicone | Tin | 36 | 40,000–50,000 |
| GI-1040 | Firm-durometer tin-cure RTV-2 silicone for foam casting | Tin | 40 | 50,000–65,000 |
| GI-1100 | Medium-durometer tin-cure RTV-2 mold making silicone | Tin | 25 | 65,000–80,000 |
| GI-1110 | Low-durometer high-elongation tin-cure RTV-2 mold making silicone | Tin | 10 | 7,000–15,000 |
| GI-1120 | Medium-durometer tin-cure RTV-2 mold making silicone | Tin | 20 | 25,000–35,000 |
| GI-1210 | Low-durometer tin-cure RTV-2 mold making silicone | Tin | 10 | 5,000–10,000 |
| GI-1220 | Medium-durometer tin-cure RTV-2 mold making silicone | Tin | 20 | 15,000–25,000 |
| GI-300B | Firm-durometer tin-cure RTV-2 potting and encapsulation silicone | Tin | 50 | 5,000–15,000 |
| GI-311B | Medium-durometer tin-cure RTV-2 potting and encapsulation silicone | Tin | 44 | 3,000–13,000 |
| GI-312B | Firm-durometer tin-cure RTV-2 potting and encapsulation silicone | Tin | 60 | 15,000–25,000 |
| GI-320B | Firm-durometer tin-cure RTV-2 potting and encapsulation silicone | Tin | 50 | 25,000–35,000 |
| GI-360B | Firm-durometer tin-cure RTV-2 potting and encapsulation silicone | Tin | 64 | 35,000–45,000 |
| GI-380B | Firm-durometer tin-cure RTV-2 potting and encapsulation silicone | Tin | 74 | 15,000–25,000 |
| GI-384 | Low-viscosity tin-cure RTV-2 silicone for urethane casting | Tin | 30 | 10,000–20,000 |
| GI-386 | Fast-cure tin-cure RTV-2 silicone base for T.O. catalyst | Tin | n.a. | 10,000–12,000 |
| GI-491 | Chemical-resistant tin-cure RTV-2 mold making silicone | Tin | 26 | 30,000–45,000 |
| GI-585 | High-elongation tin-cure RTV-2 silicone for urethane casting | Tin | 20 | n.a. |
| GI-650 | Medium-durometer tin-cure RTV-2 mold making silicone | Tin | 27 | 20,000–30,000 |
| GI-739 | Low-durometer thixotropic tin-cure RTV-2 brush-on silicone | Tin | 18 | 300,000–350,000 |
| GI-765 | Medium-durometer thixotropic tin-cure RTV-2 brush-on silicone | Tin | 28 | 400,000–450,000 |
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Help Me Pick walks through your application, then prepares a technical inquiry for our team to confirm before you order.