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Achieving perfect castings with Polyform polyurethane resin relies on the right mix. This guide will help you get accurate, reliable results every time you use Polyform for your prototyping or small-batch project needs.
Recommended Mixing Ratio for Polyform
Polyform resin is a two-part system that consists of Part A (resin) and Part B (hardener). For best results, these should be combined at a ratio of 90 parts Part A to 100 parts Part B by weight. Using digital weighing scales is strongly advised, as even small inaccuracies can affect curing or final finish quality. Always mix thoroughly until the blend is uniform to ensure the resin sets properly.
Tips for Safe and Consistent Mixing
- Wear gloves and mix in a well-ventilated area.
- Make sure all equipment and moulds are clean and dry before use.
- Measure components by weight, not volume, to avoid under- or over-curing.
- Stir slowly to minimise air bubbles, then pour promptly as Polyform sets quickly.
Polyform cures rapidly—typically ready for demoulding after about 30 minutes—so prepare everything in advance for an efficient workflow. For best detailing in moulds, ensure you work swiftly but carefully.
When Mixing Ratio Precision Matters
Correct proportions are especially important if you’re working on functional prototypes or parts requiring dimensional stability. Any deviation could lead to soft spots, incomplete curing, or weakened finished pieces. Following the 90/100 by weight ratio for Polyform Casting Resin gives the best chances of success, whether you’re a hobbyist or a professional model maker.
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Getting the mixing ratio right is at the heart of creating durable, accurate Polyform casts. See our main FAQ for more formwork and curing tips to ensure a smooth start-to-finish casting process.