--- product_id: 48505789 title: "Smooth Cast® 300 Liquid Plastic Urethane Casting Resin - Trial Unit" brand: "smooth-on" price: "£72.77" currency: GBP in_stock: true reviews_count: 10 category: "Smooth On" url: https://www.desertcart.co.uk/products/48505789-smooth-cast-300-liquid-plastic-urethane-casting-resin-trial-unit store_origin: GB region: United Kingdom --- # Paintable & machinable 15 min fast cure 1:1 mix ratio ease Smooth Cast® 300 Liquid Plastic Urethane Casting Resin - Trial Unit **Brand:** smooth-on **Price:** £72.77 **Availability:** ✅ In Stock ## Summary > ⚡ Cast like a pro, finish like a boss! ## Quick Answers - **What is this?** Smooth Cast® 300 Liquid Plastic Urethane Casting Resin - Trial Unit by smooth-on - **How much does it cost?** £72.77 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/48505789-smooth-cast-300-liquid-plastic-urethane-casting-resin-trial-unit) ## Best For - smooth-on enthusiasts ## Why This Product - Trusted smooth-on brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Ultra-Low Viscosity:** Pour with precision and achieve bubble-free, bright white results effortlessly. - • **Rapid 15-Minute Cure:** Get flawless, durable castings in a flash—no waiting, no hassle. - • **Perfect 1:1 Mix Ratio:** Simplify your workflow with an easy, equal-part blend every time. - • **Moisture & Solvent Resistant:** Ensure long-lasting durability for your sculptures and models in any environment. - • **Versatile Finish-Ready Material:** Sand, prime, and paint your creations for professional-grade prototypes and props. ## Overview Smooth Cast® 300 is a premium liquid urethane resin designed for fast, bubble-free casting with a convenient 1:1 mix ratio. Its ultra-low viscosity ensures easy pouring, while the cured plastic is tough, paintable, and resistant to moisture and mild solvents—ideal for professional prototypes, sculptures, and special effects. ## Description Smooth-On Smooth Cast 300 Series of liquid plastics are ultra-low viscosity casting resins that yield castings that are bright white and virtually bubble free. Vacuum degassing is not necessary. They offer the convenience of a one to one mix ratio (one part A to one part B by volume). Fully cured castings are tough, durable, machinable and paintable. They resist moisture and mild solvents. Applications for Smooth-Cast Liquid Plastics include reproducing small to medium size sculptures,making prototype models, roto cast pieces, and special effect props. Review: Awesome - Very good bought lots of this and will buy lots more easy to work with and great results all round Review: Pefect casr first time - I had tried another brand of resin and had lots of issues with it not setting or only working with one type of silicone. There is no problem with this product; I mixed, pored and after 10 minutes had a perfect copy. Will use again. ## Features - Causes skin irritation. - Harmful if inhaled. - May cause allergy or asthma symptoms or breathing difficulties if inhaled. - May cause an allergic skin reaction. - May cause damage to organs through prolonged or repeated exposure. - May cause respiratory irritation. - Suspected of causing cancer. - 15 minute cure time - Rigid white plastic - Low viscosity - easy to pour - 1A:1B by volume mix ratio - Can be sanded, primed and painted ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B004BN7G0E | | Best Sellers Rank | 572,439 in Home & Kitchen ( See Top 100 in Home & Kitchen ) 1,742 in Sculpting Moulding & Casting | | Brand | Smooth-On | | Compatible Material | Plastic | | Customer Reviews | 4.7 out of 5 stars 1,128 Reviews | | Grit Material Type | Plastic | | Grit Number | 300 | | Grit Type | Fine | | Grit material | Plastic | | Grit type | Fine | | Item Dimensions | 18.8 x 15.2 x 7.9 centimetres | | Item Weight | 907 g | | Item dimensions L x W x H | 18.8 x 15.2 x 7.9 centimetres | | Item weight | 907 g | | Manufacturer | Smooth-On, Inc. | | Manufacturer Part Number | 47641 | | Material | Urethane | | Model Number | 47641 | | Number of Items | 1 | | UPC | 751635476417 | | Unit Count | 1.0 count | ## Product Details - **Brand:** Smooth-On - **Grit material:** Plastic - **Grit type:** Fine - **Item dimensions L x W x H:** 18.8 x 15.2 x 7.9 centimetres - **Material:** Urethane ## Images ![Smooth Cast® 300 Liquid Plastic Urethane Casting Resin - Trial Unit - Image 1](https://m.media-amazon.com/images/I/81gwmekNnqL.jpg) ![Smooth Cast® 300 Liquid Plastic Urethane Casting Resin - Trial Unit - Image 2](https://m.media-amazon.com/images/I/71ZWTS1-Q2L.jpg) ![Smooth Cast® 300 Liquid Plastic Urethane Casting Resin - Trial Unit - Image 3](https://m.media-amazon.com/images/I/81ubKEjBDDL.jpg) ![Smooth Cast® 300 Liquid Plastic Urethane Casting Resin - Trial Unit - Image 4](https://m.media-amazon.com/images/I/71Koo4ru1vL.jpg) ![Smooth Cast® 300 Liquid Plastic Urethane Casting Resin - Trial Unit - Image 5](https://m.media-amazon.com/images/I/71LJ0Lk-VZL.jpg) ## Available Options This product comes in different **Color** options. ## Questions & Answers **Q: Can I add glitter to this?** A: I've used 325 with glitter pigments, and it works very well. You'll have to add a decent amount of glitter and it will take longer to cure. **Q: Can I use this to cast a dome-shaped mask using a silicone mold? Will it stay liquid long enough for me to tilt it back & forth to form an even coat?** A: Smooth-Cast 300 is a snap cure material - a better choice may be Smooth-Cast 325 or Smooth-Cast 65D, both of which have a gradual cure profile. **Q: is it machinable?** A: Yeah, to an extent. I’ve taken a dremle tool to casted plastic to sand down parts and remove unwanted flashing that occurs. It’s pretty tough stuff, let it cure for a day or two before sanding or working on thinner areas, but I’ve even taken a hacksaw to some castings and they have held up just fine. **Q: Is this a silicone or a urethane?** A: This is a urethane casting resin. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Awesome *by S***N on 8 November 2020* Very good bought lots of this and will buy lots more easy to work with and great results all round ### ⭐⭐⭐⭐⭐ Pefect casr first time *by C***G on 2 September 2016* I had tried another brand of resin and had lots of issues with it not setting or only working with one type of silicone. There is no problem with this product; I mixed, pored and after 10 minutes had a perfect copy. Will use again. ### ⭐⭐⭐⭐⭐ Five Stars *by A***R on 23 October 2017* Good buy. A little expensive. But works as moulds .u have to work fast and accurate ## Frequently Bought Together - Smooth-Cast™ 300: Bright White, Low Viscosity, Liquid Plastic Casting Resin - Pint Unit - Smooth-On Mold Star™ 16 Fast Platinum Silicone Rubber, Silicone Mold Making Kit - Pint Unit - Smooth-On Universal Mold Release - 14 Fluid Ounce Aerosol Can --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.uk/products/48505789-smooth-cast-300-liquid-plastic-urethane-casting-resin-trial-unit](https://www.desertcart.co.uk/products/48505789-smooth-cast-300-liquid-plastic-urethane-casting-resin-trial-unit) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-06-30*