Bluesil RTV 3325P
High-quality, kneadable two-component silicone with excellent detail reproduction for precise impressions, even on vertical surfaces.
BLUESIL RTV 3325 P — a thixotropic paste version of the 3325 system.
Non-flowing — applied with a brush or by hand to vertical surfaces. Ideal for archaeology, paleontology, and casting non-movable models (rock reliefs, facades, fossils). Mix with CATA 83 in a 100:4 ratio. Shipped from our Swiss warehouse.
documents
Internal reference:
40-928
HS Code:
39100000
BLUESIL RTV condensation silicones – the classic two-component family for mold making
The BLUESIL RTV 32xx series consists of two-component silicone elastomers that cure by polycondensation at room temperature. The catalyst is a tin complex; the curing product is alcohol. This chemistry offers two practical advantages over platinum-catalyzed addition-curing RTVs (such as RTV 141 / 147 / 3040):
- No platinum inhibition: Condensation-curing RTVs can be cast onto virtually any substrate—sulfur, tin, amines, or PVC do not interfere with curing. In practice, this is a decisive advantage when working with models made of unknown materials (art, archaeology, artifacts).
- Less processing effort: No separate venting chamber required, no preliminary substrate testing. Manual processing is also possible without any problems
As a trade-off, condensation-curing RTV exhibits slight linear shrinkage (0.4–1.2% depending on the variant)—for applications requiring high dimensional accuracy or tight tolerances, addition-curing systems are the better choice.
BLUESIL RTV 3325 P in detail
BLUESIL RTV 3325 P is the thixotropic brush-on version of the 3325 family—the "P" stands for "paste." Unlike all other 32xx RTV products (which are flowable), 3325 P is a non-flowing paste that is applied directly to models by hand or with a brush.
This makes it possible to use applications where gravity casting does not work:
- The model is vertical and cannot be moved
- The model is too large or too fragile for horizontal handling
- The model is located in situ (on site, at the excavation site, at the structure)
The gray-white silicone dough is easy to work with using damp hands (which prevents sticking). After 16 hours at 23°C, the mold is ready to be removed.
What's in this container?
This product contains the base component RTV 3325 P. BLUESIL CATA 83 (a liquid, lemon-yellow paste) is added as a catalyst in a ratio of 100:4—knead by hand until the color is uniform.
Typical applications
- Archaeology: Casting bas-reliefs and statues in situ – rock art, tombstones, and facade ornaments that cannot be moved
- Paleontology: Casting fossils that are embedded in rock or too fragile to be removed
- Decorative objects: rosettes and statuettes in historic preservation, facade reliefs
- Heritage Preservation: Documentary Casts of Historical Artworks Prior to Restoration
Processing Tip from Elkem
For models with deep undercuts, Elkem recommends a two-step process: first, apply several thin layers of RTV 3325 P with a brush (to completely cover the surface), then fill the undercuts with RTV 3325 flowable + CATA 83. This creates a multi-layer mold with excellent detail and substantial thickness.
Specifications
| Base Color | Gray and white |
| consistency | Non-flowing paste (thixotropic) |
| density | 1.20 g/cm³ |
| Mixing ratio with CATA 83 | 100 to 4 |
| Shore A | 25 |
| tensile strength | 2.5 MPa |
| elongation at break | 350% |
| Tear resistance | 9 kN/m |
| Linear shrinkage (7 days at 23°C) | 0.4% |
| Gel time | 90 min |
| demolding time | 4:00 p.m. |
| End properties | after 3 days |
Storage and Containers
Can be stored for up to 12 months at temperatures ranging from −5°C to +30°C. Packaging: 5-kg canisters or 25-kg plastic drums. CATA 83 is supplied in the appropriate quantities.
BLUESIL RTV 3325 P is supplied by SILITECH AG with technical support, a batch certificate, and shipping from our Swiss warehouse within 24 hours.
Frequently Asked Questions About BLUESIL RTV 3325 P
Answers regarding thixotropy, archaeological applications, and manual application of BLUESIL RTV 3325 P.
The thixotropic property is achieved through modified silica fillers that form a weak gel network. Under shear stress (from a brush or hands), the material flows; when at rest, it remains in place. This is crucial for applications on vertical surfaces —rock reliefs, facades, gravestones, and large statues cast in situ.
The three classic applications are archaeology (casting bas-reliefs and statues), paleontology (casting fossils), and historic preservation/decoration (historic rosettes, facade ornaments). Anywhere where the model cannot be moved and gravity casting is not feasible.
Lightly moisten your hands (to prevent sticking), then knead the 4 parts of catalyst into 100 parts of base until the yellow CATA-83 color is completely incorporated into the mixture (no streaks of color should be visible). Then apply directly to the model using a brush or your hands, pressing down to avoid air bubbles.
Yes, this is actually recommended for models with deep undercuts. First, apply a thin base coat of thixotropic 3325-P paste with a brush (to fill all the details), then fill in the coarser geometries with flowable RTV 3325. This creates a multi-layer mold with excellent detail reproduction and high mechanical strength.
product specifications
| Physical properties | |
|---|---|
| Paint cured | White |
| Self-leveling | No |
| consistency | Thixotropic |
| product information | |
|---|---|
| container | 1 kg or 5 kg or 25 kg |
| brand | Bluesil |
| network type | Condensation (tin) |
| manufacturer | Elkem Silicones |
| Number of components | 2K (two-component) |
| mixing ratio | 100:4 |
| Additional features | |
|---|---|
| UV resistance | No |
| product approvals | |
|---|---|
| food contact | No |
| Suitable for medical use | No |
| Areas of application | |
|---|---|
| Main application | Mold making or Prototyping |
| Electrical Properties | |
|---|---|
| Electrical insulation | No |
| Uncategorized | |
|---|---|
| Density (g/cm³) | 1.2 |
| Viskosität unvernetzt (mPa·s) | 35 |
| Pot life (min) | 90 |
| Entformzeit (min) | 24 |
| Tensile strength (MPa) | 2.5 |
| Elongation at break (%) | 350 |
| Reißfestigkeit (N/mm) | 9 |
| keywords | |
|---|---|
| keywords | |
| Mechanical properties | |
|---|---|
| Shore A hardness | 25.0 Shore A |
| tensile strength | 2.5 MPa |
| elongation at break | 350.0 % |
| Tear resistance | 9.0 kN/m |
| Linear shrinkage | < 0.4% |
| processing | |
|---|---|
| Pot life at 23°C | 90.0 min |
| demolding time | 960.0 min |
| Physical & Thermal | |
|---|---|
| Density (23°C) | 1.2 g/cm³ |
| Temperature resistance (duration) | -50 to 200 °C |
| Peak temperature (short-term) | 250 °C |
| storage | |
|---|---|
| Shelf life in original packaging | 12 months |
| Storage temperature | -5 to 30 °C |