---
product_id: 1871175
title: "Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit"
brand: "smooth-on"
price: "₨33361"
currency: LKR
in_stock: true
reviews_count: 13
category: "Smooth On"
url: https://www.desertcart.lk/products/1871175-smooth-cast-300-bright-white-ultra-low-viscosity-liquid-pint
store_origin: LK
region: Sri Lanka
---

# Bright white, ultra-low viscosity Shore 70D hardness, machinable 3-min pot life, 10-min cure Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit

**Brand:** smooth-on
**Price:** ₨33361
**Availability:** ✅ In Stock

## Summary

> ⚡ Cast fast, shine bright, and craft like a pro!

## Quick Answers

- **What is this?** Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit by smooth-on
- **How much does it cost?** ₨33361 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.lk](https://www.desertcart.lk/products/1871175-smooth-cast-300-bright-white-ultra-low-viscosity-liquid-pint)

## 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

- • **Simple 1:1 Mix Ratio:** No fancy tools required—just equal parts for consistent, reliable casting every time, trusted by pros and hobbyists alike.
- • **Rapid Productivity Boost:** Get multiple flawless castings in just 10 minutes—perfect for fast-paced projects and tight deadlines.
- • **Vibrant Bright White Base:** Creates strikingly bright, smooth castings that serve as the perfect canvas for custom paints and finishes.
- • **Durable & Machinable Strength:** Rigid Shore 70D hardness lets you drill, sand, carve, and paint with confidence—ideal for prototypes and display pieces.
- • **Effortless Bubble-Free Finish:** Ultra-low viscosity formula naturally releases trapped air—no vacuum degassing needed for pristine, professional results.

## Overview

Smooth-Cast 300 is a fast-curing, ultra-low viscosity two-part polyurethane resin that produces bright white, bubble-free castings with a 3-minute pot life and 10-minute demold time. Its durable Shore 70D hardness makes it machinable and paintable, while the easy 1:1 mix ratio ensures professional-quality results without vacuum degassing. Perfect for prototyping, cosplay, and detailed mold work.

## Description

Smooth Cast 300 is a liquid plastic ,ultra-low viscosity casting resin that yields castings that are bright white and virtually bubble-free. Vacuum degassing is not necessary. It offers the convenience of a one to one mix ratio (by volume). 3 minute pot life: 10 minute demold time: Mixed viscosity 80 cps: 70D shore hardness Fully cured castings are tough, durable, machinable and paintable. Read MSDS before use - Adult Supervision Required. Keep Out of the Reach of Children - for more information visit www.smooth-on.com

Review: Works Amazing. Used for Complex Thin Walled Two-Part Mold. Just Don't Add Filler/Color or Degas - Worked perfectly for my needs. Very little bubbling even when pouring it directly into a two-part thin walled cast squish mold with very little venting built into the mold. Even though my casted part is probably 1/8 of an inch thick at its thickest point, and probably half that at it's thinnest, this product is still very durable. Surprisingly. I was expecting I may needed to get the Smooth Cast Task series product over the Smooth Cast 300 to get what I needed for such a thin cast. First attempt at a cast I tried degassing the mixed resin. Spent one minute mixing. And one minute or so degassing. Which should have left me with one final minute of potlife. Nope, within a 3 second period between having my eyes on the resin in the chamber, I look back and see a very hot eruption of resin that instant cured into a soft foam in the shape of magma pouring out of the cup like a volcano lol. Lesson #1 learned. No degassing. First cast I used release (really just cooking spray) and black pigment powder. And it came out horrible. Finish was rough and textured, and the color was grey although I used a ton of black pigment. And ultimately it made the cast extremely brittle and it broke in two places while sanding/trimming. Lesson #2 learned. No additives, and avoid release agents (or at least particularly non-cast specific release agents). Without any additives or any release (still released perfectly fine without any chemical release) it came out very smooth and very durable. It also sands amazingly well. Doesn't clog up sanding paper, sands down powdery and easily. Also the cast was a motorcycle helmet spoiler that isn't sold separately anywhere. Was a very expensive handmade Portuguese carbon fiber racing helmet. I decided to learn about molding and casting and made myself a new one using a spoiler to the same model I bought for my girlfriend as a gift. Think of, two birds one stone lol. Gift + master for my own spoiler. For my very first cast, being so complex as it was, and being such an amazing success.. I am completely happy with myself and the results of the various products I've used. Will say though, silicone mold making is definitely much more difficult than the resin casting process haha. Especially two part molds making with non-flat masters.
Review: Works perfectly, I recommend it - My first time casting a mold. Works perfect. I recommend it.

## Features

- FAST-CURING BRIGHT WHITE CASTING RESIN – Smooth-Cast 300 is an ultra-low viscosity, two-part liquid polyurethane plastic that produces bright white castings with excellent detail. Its free-flowing formula fills intricate molds with ease for professional-quality results.
- VIRTUALLY BUBBLE-FREE CASTINGS – The ultra-low viscosity formula allows trapped air to escape naturally, eliminating the need for vacuum degassing in most applications. Create smooth, high-quality castings with minimal bubbles and outstanding surface finish.
- RAPID SET & DEMOLD TIMES – Designed for high productivity with a 3-minute pot life and 10-minute cure time, allowing you to make multiple castings in a short period. Ideal for prototyping, production runs, cosplay props, model making, and special effects.
- STRONG, RIGID & MACHINABLE – Cures to a durable Shore 70D hardness, producing rigid castings that can be drilled, sanded, carved, machined, and painted. The bright white finish also provides an excellent base for custom colors and decorative finishes.
- EASY 1:1 MIXING FOR PROFESSIONAL RESULTS – Mix equal parts of Part A and Part B by volume—no specialized equipment required. Compatible with most silicone rubber molds and trusted by artists, designers, manufacturers, prop makers, and hobbyists for detailed, reliable castings every time.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B004BN7G0E |
| Best Sellers Rank | #12,173 in Arts, Crafts & Sewing ( See Top 100 in Arts, Crafts & Sewing ) #110 in Sculpture Molding & Casting Products |
| Brand | Smooth-On |
| Brand Name | Smooth-On |
| Compatible Material | Glass, Metal, Plastic, Stone, Wood |
| Customer Reviews | 4.7 out of 5 stars 1,321 Reviews |
| Grit Material | Plastic |
| Grit Material Type | Plastic |
| Grit Number | 300 |
| Grit Type | Fine |
| Item Dimensions | 7.4 x 6 x 3.1 inches |
| Item Type Name | Casting Resin |
| Item Weight | 2 pounds |
| Item dimensions L x W x H | 7.4 x 6 x 3.1 inches |
| Manufacturer | Smooth-On, Inc. |
| Material | Plastic |
| Material Type | Plastic |
| Model | 47641 |
| Number of Items | 1 |
| Part Number | 47641 |
| UPC | 751635476417 |
| Unit Count | 1 Count |

## Product Details

- **Brand:** Smooth-On
- **Grit Material:** Plastic
- **Grit Type:** Fine
- **Item dimensions L x W x H:** 7.4 x 6 x 3.1 inches
- **Material:** Plastic

## Images

![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 1](https://m.media-amazon.com/images/I/81gwmekNnqL.jpg)
![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 2](https://m.media-amazon.com/images/I/71ZWTS1-Q2L.jpg)
![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 3](https://m.media-amazon.com/images/I/81ubKEjBDDL.jpg)
![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 4](https://m.media-amazon.com/images/I/71Koo4ru1vL.jpg)
![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 5](https://m.media-amazon.com/images/I/71LJ0Lk-VZL.jpg)

## Available Options

This product comes in different **Size** 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

### ⭐⭐⭐⭐⭐ Works Amazing. Used for Complex Thin Walled Two-Part Mold. Just Don't Add Filler/Color or Degas
*by B***N on December 18, 2024*

Worked perfectly for my needs. Very little bubbling even when pouring it directly into a two-part thin walled cast squish mold with very little venting built into the mold. Even though my casted part is probably 1/8 of an inch thick at its thickest point, and probably half that at it's thinnest, this product is still very durable. Surprisingly. I was expecting I may needed to get the Smooth Cast Task series product over the Smooth Cast 300 to get what I needed for such a thin cast. First attempt at a cast I tried degassing the mixed resin. Spent one minute mixing. And one minute or so degassing. Which should have left me with one final minute of potlife. Nope, within a 3 second period between having my eyes on the resin in the chamber, I look back and see a very hot eruption of resin that instant cured into a soft foam in the shape of magma pouring out of the cup like a volcano lol. Lesson #1 learned. No degassing. First cast I used release (really just cooking spray) and black pigment powder. And it came out horrible. Finish was rough and textured, and the color was grey although I used a ton of black pigment. And ultimately it made the cast extremely brittle and it broke in two places while sanding/trimming. Lesson #2 learned. No additives, and avoid release agents (or at least particularly non-cast specific release agents). Without any additives or any release (still released perfectly fine without any chemical release) it came out very smooth and very durable. It also sands amazingly well. Doesn't clog up sanding paper, sands down powdery and easily. Also the cast was a motorcycle helmet spoiler that isn't sold separately anywhere. Was a very expensive handmade Portuguese carbon fiber racing helmet. I decided to learn about molding and casting and made myself a new one using a spoiler to the same model I bought for my girlfriend as a gift. Think of, two birds one stone lol. Gift + master for my own spoiler. For my very first cast, being so complex as it was, and being such an amazing success.. I am completely happy with myself and the results of the various products I've used. Will say though, silicone mold making is definitely much more difficult than the resin casting process haha. Especially two part molds making with non-flat masters.

### ⭐⭐⭐⭐⭐ Works perfectly, I recommend it
*by S***N on June 5, 2026*

My first time casting a mold. Works perfect. I recommend it.

### ⭐⭐⭐⭐⭐ ONYX vs SmoothCast-300
*by M***N on January 27, 2016*

By far the BEST from SmoothOn. At this time I have to say that SmoothOn is a good company. Thanks Jeremy for your help. Also the pricing at Amazon for the trial units is cheaper than the manufacturer (SmoothOn) or anyone else. Now, for the comparison: SoothOn has the ONYX (Fast & Slow) which dries Black. Both the ONYX fast and slow are EXTREMELY finicky, troubled resins. They tend to bubble up on humid days and also develop BLISTERS (big blobs) due to heat. The ONYX if you must have black is fine for small parts. The SmoothCast-300 is a fantastic epoxy resin. BEWARE: It dries fast, very fast or within 2 minutes gets hard enough so it can't be poured. I started pouring in the mold and was left with the stream coming out of the cup running down the mold. It looked like those modern "Pouring in the Glass" sculptures. So, I CUT THE EXCESS, left what was already there, and poured a second layers to fill the remaining mold cavity. It ATTACHES well to the already dried resin. So, SC-300 LAYERS WELL and dries "VERY WHITE". It is EASILY SANDED, and behaves like wood. It DRIES IN 5 MIM. enough to sand it. By far, SC-300 is the easiest to work with between Onyx and SC-300. It is also hard and a bit flexible, almost exactly like plastic. In every way, it is real plastic. If you try to sink you nail into it, no way you can. I recommend SC-300 for anything dealing with industrial or commercial parts, which is what I do.

## 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

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*Product available on Desertcart Sri Lanka*
*Store origin: LK*
*Last updated: 2026-09-08*