{"product_id":"smooth-on-urethane-casting-resin-ultra-black-pint-fast-curing-80d-hard-durable-finish","title":"Smooth-On urethane casting resin Ultra-Black Pint — fast-curing, 80D hard durable finish","description":"\u003cstrong\u003eSmooth-Cast Onyx Fast is a mercury-free, ultra-black urethane casting resin that cures quickly at room temperature to form a hard, durable 80D plastic.\u003c\/strong\u003e\n\n\u003cp\u003eSmooth-Cast Onyx Fast is a high-performance, fast-curing urethane resin in a convenient pint unit formulated for deep black castings. It blends 1A:1B by volume, pours easily thanks to low viscosity, and delivers a dense, opaque finish useful for prototypes, props, small parts, and decorative objects where a consistent, solid black appearance is desired. Designed for makers and professionals who need speed and convenience, Onyx Fast balances short working time with a robust final hardness.\u003c\/p\u003e\n\n\u003ch3\u003eHow quickly will Smooth-Cast Onyx Fast cure and how much working time do I have?\u003c\/h3\u003e\n\n\u003cp\u003eOnyx Fast is engineered for rapid turnaround jobs: it has a very short pot life and reaches demold strength in minutes. Expect only a couple minutes of workable time and demolding within roughly 10–15 minutes, depending on part thickness and ambient conditions.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePot life (working time): approximately 2.5 minutes\u003c\/li\u003e\n  \u003cli\u003eDemold\/cure time: about 10–15 minutes at room temperature\u003c\/li\u003e\n  \u003cli\u003eRoom-temperature cure—no oven required for standard cure\u003c\/li\u003e\n  \u003cli\u003eFast processing suits small runs and quick prototypes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat mixing and pouring steps ensure consistent, bubble-free results?\u003c\/h3\u003e\n\n\u003cp\u003eMixing is straightforward because the system uses a 1:1 by-volume ratio, reducing measurement errors. Its low viscosity helps the resin flow into fine details, but because the pot life is short, mix and pour promptly and work with small batches for best results.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMix ratio: 1A:1B by volume for simple measuring\u003c\/li\u003e\n  \u003cli\u003eLow viscosity for good mould release and detail reproduction\u003c\/li\u003e\n  \u003cli\u003eStir thoroughly and pour immediately to avoid premature gel\u003c\/li\u003e\n  \u003cli\u003eConsider vacuum or pressure casting for near-perfect surfaces\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the finished material properties and typical uses?\u003c\/h3\u003e\n\n\u003cp\u003eThe cured material is a hard, opaque black plastic with a Shore hardness around 80D, offering improved physical strength and heat resistance compared with many softer casting urethanes. It’s suited to functional prototypes, theatrical props, small tooling, and parts where an intense black aesthetic or light-blocking body is required.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eShore hardness: approximately 80D for rigid parts\u003c\/li\u003e\n  \u003cli\u003eUltra-black, opaque finish ideal for non-reflective elements\u003c\/li\u003e\n  \u003cli\u003eHigher heat and mechanical resistance than softer urethanes\u003c\/li\u003e\n  \u003cli\u003eApplications: props, prototypes, housings, jewellery, art pieces\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe product is mercury-free and formulated for ease-of-use in studio or shop environments, but always follow safety guidance for urethane resins including gloves, eye protection, and adequate ventilation.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWho is this for?\u003c\/strong\u003e Smooth-Cast Onyx Fast is best suited for model makers, prop fabricators, product developers, and hobbyists who need quick cure times, a rich black finish, and a rigid final part. It’s particularly useful when fast iteration is required or when parts must be produced quickly in small batches. Avoid large-volume pours unless you have experience managing short pot-life resins; for longer working time, consider a slower Onyx variant.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can Smooth-Cast Onyx Fast be mixed by volume?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — it uses a 1A:1B by-volume mix ratio for easy measuring and fast setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: How long until parts can be demolded?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Typical demold is about 10–15 minutes at room temperature, depending on part thickness.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Smooth-On","offers":[{"title":"Default Title","offer_id":55296583106897,"sku":"B00IMIEP8K","price":69.35,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1086\/5567\/3681\/files\/smooth-on-smooth-cast-onyx-fast-front-pint.jpg?v=1791943905","url":"https:\/\/craftiche.co.uk\/products\/smooth-on-urethane-casting-resin-ultra-black-pint-fast-curing-80d-hard-durable-finish","provider":"Craftiche","version":"1.0","type":"link"}