Terephthalic Fire-Retardant Gelcoat Resin
SPR 401 FRGCThixotropic terephthalic fire-retardant gelcoatSPR 401 · Terephthalic Polyester Resins
Thixotropic terephthalic fire-retardant gelcoat for the mould-face surface of fire-retardant FRP components.
Review the official product data sheet for specifications and application information.
Price
Price on Request
Industrial resin pricing varies based on:
- Order Quantity
- Resin Grade
- Current Raw Material Rates
Product details
| Catalogue Code | SPR 401 FRGC |
|---|---|
| Resin Chemistry | Terephthalic unsaturated polyester gelcoat, fire-retardant |
| Supply Condition | Non-accelerated · thixotropic |
| Reference Cure System | MEKP 1.5% + Cobalt Octoate 0.4% — added separately during use |
Typical specification
| Appearance | Opaque, thick pigmented liquid |
|---|---|
| Colour | White, grey or custom colour |
| Viscosity, 2 rpm | 12,000–18,000 cPs |
| Viscosity, 20 rpm | 2,000–3,500 cPs |
| Thixotropic Index | 4.5–6.0 |
| Gel Time | 12–22 minutes at 25 °C |
| Density | 1.25–1.45 g/cm³ |
| Styrene Content | 28–35% by weight |
Typical values from the Samrat Poly Resins product catalogue, 2026 edition. They are not guaranteed specifications or finished-component properties; confirm the current values for your order and trial the grade on your own process.
SPR 401 FRGC is the terephthalic fire-retardant gelcoat of the SPR 401 family: a thixotropic gelcoat with excellent mechanical properties, per the catalogue, for the mould-face surface of fire-retardant FRP components. It is listed for fire-retardant gelcoat surfaces for rail and transport composite components, automotive composite components and fire-retardant moulded FRP parts. It is supplied non-accelerated and thixotropic, with MEKP and cobalt octoate added separately during use. No fire classification or test result is published for this grade.
The orthophthalic fire-retardant gelcoat is SPR 201 FR-GC. The catalogue's selection guide pairs a fire-retardant gelcoat with the fire-retardant laminating resin of the same project.
Key features
- Thixotropic terephthalic fire-retardant gelcoat (SPR 401 FRGC)
- Excellent mechanical properties, per the catalogue
- White, grey or custom colour
- Typical thixotropic index 4.5–6.0; gel time 12–22 minutes at 25 °C
Applications
- Fire-retardant gelcoat surfaces for rail and transport composite components
- Automotive composite components
- Fire-retardant moulded FRP parts
Product role
The gelcoat is the outer, fire-exposed face of a moulded part. SPR 401 FRGC gives the terephthalic family its own fire-retardant surface coat, with a high thixotropic index (4.5–6.0) to hold film thickness on vertical mould faces.
Fire-retardant describes the gelcoat's formulation, not a certified rating: fire classifications apply to the tested finished construction. Share the project standard, component and laminate details before selection.
Supply and cure
- Supply condition
- Non-accelerated · thixotropic
- Reference cure system
- MEKP 1.5% + Cobalt Octoate 0.4% — added separately during use
Processes and where this grade fits
SPR 401 FRGC is a thick, highly thixotropic, pigmented fire-retardant gelcoat for the outer surface of transport and automotive composite parts.
| Process or use | Role of this grade | What to confirm |
|---|---|---|
| Brush or spray gelcoat on open moulds | Listed role — fire-retardant surfaces | Film thickness on vertical faces and application equipment |
| Rail and transport composite components | Listed role | The rail fire standard and tested construction |
| Automotive composite components | Listed role | The component and vehicle maker’s requirement |
| Fire-retardant moulded FRP parts | Listed role | The complete build behind the gelcoat |
| Parts without a fire requirement | Not this grade’s role | GP Gelcoat Resin or ISO Gelcoat |
Process-selection considerations
- The thixotropic index of 4.5–6.0 is high: the gelcoat is built to hold film thickness on vertical faces. Confirm spray or brush behaviour on your equipment.
- Viscosity is 12,000–18,000 cPs at 2 rpm and 2,000–3,500 cPs at 20 rpm typical — thick at rest, thinner under shear.
- Choose colour at the start: white, grey or custom colour. The pigment is part of the tested surface.
- Use it over the project’s fire-retardant laminating resin, and submit the two together for testing as one construction.
- Reference cure: MEKP 1.5% with cobalt octoate 0.4%, added separately; gel time 12–22 minutes at 25 °C typical.
Limitations and trial requirements
- No fire classification is published for SPR 401 FRGC. Classifications belong to the tested finished construction.
- Gloss, hardness, weathering and water-resistance values are not published for this grade.
- Film thickness and back-up timing must be established on the production mould.
- Trial the grade on the real part, mould and shop conditions before production. The catalogue values are typical liquid-resin properties, not guaranteed limits or finished-part performance.
Before you select this grade
- The values on this page are typical. Final selection should be confirmed against your own process, a trial result and the current technical documentation for the grade.
- The Technical Data Sheet linked on this page carries these same typical values. No Safety Data Sheet is published on this site for this grade; request current safety information before use.
- Never mix a concentrated peroxide initiator directly with a cobalt accelerator. Add each to the resin separately, according to the confirmed process.
- Store resin, initiators and accelerators separately, in original sealed containers, cool, shaded and away from heat and ignition sources. Use suitable personal protective equipment and adequate ventilation.
