Quick facts
- Grades compared
- SPR 201 GPC · SPR 301 LV
- Chemistry
- Orthophthalic (GP Clear) · isophthalic (LV)
- Viscosity
- 350–450 cPs · 80–180 cPs at 25 °C
- Decided by
- The reinforcement (glass fibre or jute) and the moulding cycle
What differs
GP Clear Resin is the supplier’s standard clear orthophthalic grade for general hand lay-up, spray-up, moulding and lamination with glass fibre. SPR 301 LV is an isophthalic grade the catalogue designs and lists for jute reinforcement. The two differ in chemistry, and more visibly in how they flow and how long they stay workable.
At 80–180 cPs, SPR 301 LV is far thinner than GP Clear Resin’s 350–450 cPs, which helps a resin soak into a natural fibre such as jute. Its gel time is also much longer — 40–90+ minutes at 25 °C against under 8 minutes — and its reference cure uses less cobalt: MEKP 1.5% with cobalt octoate 0.2%, each added separately.
How to decide
Start from the reinforcement. For glass-fibre lay-up, spray-up and general moulding, GP Clear Resin is the listed general-purpose starting grade. For jute-reinforced mouldings, SPR 301 LV is the grade the catalogue designed for jute.
Then check the cycle. SPR 301 LV’s long gel time has to be planned into mould turnaround; a line built around GP Clear Resin’s short gel time will run differently. If the part also faces water or chemical service, the isophthalic chemistry of SPR 301 LV is one consideration, but its listed role is jute impregnation, not chemical service.
What the data does not tell you
Neither record gives mechanical figures for a jute or glass laminate, or says how much resin a given jute fabric will absorb. Jute varies in weave, weight and moisture content, and those change wet-out and cure. Using SPR 301 LV with other reinforcements, or GP Clear Resin with jute, should be confirmed with a trial on your own mould.
Sources, roles and the Nepal enquiry path
GP Clear Resin values are from its supplier Technical Data Sheet as recorded on this site. SPR 301 LV values are the typical specification in the supplier’s 2026 product catalogue; no Technical Data Sheet for that grade has been published on this site.
Samrat Poly Resins, India manufactures the grade and issues its technical information. Samrat FRP Traders is the Nepal supplier and importer and handles enquiries; price, packaging, lead time and stock in Nepal are confirmed on enquiry.
GP Clear Resin vs SPR 301 LV: decision table
| Criterion | GP Clear Resin (SPR 201 GPC) | Low-Viscosity Grade Resin (SPR 301 LV) |
|---|---|---|
| Chemistry | Clear orthophthalic unsaturated polyester | Low-viscosity isophthalic unsaturated polyester |
| Appearance | Clear liquid | Clear, water-white to light-straw liquid |
| Supply condition | Non-accelerated; thixotropy not stated | Non-accelerated · non-thixotropic |
| Viscosity | 350–450 cPs | 80–180 cPs at 25 °C |
| Gel time | Under 8 minutes | 40–90+ minutes at 25 °C |
| Styrene content | 33–40% | 42–50% by weight |
| Reference cure | MEKP + cobalt octoate, dosed per the TDS; cure time 45 minutes–1.5 hours | MEKP 1.5% + cobalt octoate 0.2%, added separately |
| Listed uses | Hand lay-up and spray-up laminates, FRP water tanks, roofing sheets, sanitaryware, panels, moulding, cooling-tower components | Impregnation of jute reinforcement; jute-reinforced composite mouldings |
| Choose when… | The reinforcement is glass fibre and the work is general lay-up or moulding | The reinforcement is jute and the cycle can accommodate a long gel time |
Sources: GP Clear Resin values from its supplier Technical Data Sheet (SPR-TDS-GCR) as recorded on this site; SPR 301 LV values from the supplier’s 2026 product catalogue. Typical values describe a grade; they are not batch guarantees or acceptance limits.
Frequently asked questions
Why does jute need a low-viscosity resin?
A thinner resin soaks into a natural fibre more readily. SPR 301 LV is the grade the catalogue designs for jute, at 80–180 cPs.
Can I thin GP Clear Resin instead?
The product documents do not give a thinning procedure. Adding styrene or anything else changes the cure; confirm any change with the supplier and a trial.
Is SPR 301 LV better because it is isophthalic?
Not in general. It is listed for jute impregnation. For glass-fibre lay-up, GP Clear Resin is the listed general-purpose grade.
Why is the SPR 301 LV gel time so long?
The catalogue lists 40–90+ minutes at 25 °C with a reference cure of MEKP 1.5% and cobalt octoate 0.2%. Plan the moulding cycle around it.