Epoxy resin calculator
Size up your mould, list your pours and enter the mix ratio printed on your resin. You get the resin and hardener for every layer, measured the way your product asks, by volume or by weight.
Working safely with epoxy
- Epoxy resins are among the most common causes of allergic skin rashes at work. Skin contact is the main way in.
- Once you are sensitised, even a small amount can bring the rash back each time, so keep resin off your skin from the first pour.
- Wear chemical-resistant gloves such as thick nitrile. Not cotton or latex: they can hold the chemicals against your skin.
- Wear eye protection and long sleeves, and work with good ventilation to carry vapours away.
- Wash your hands with soap and warm water after working, and clean or bin anything with resin on it.
- Follow the label and the safety data sheet of your own resin and hardener.
From the UK Health and Safety Executive, Ireland's Health and Safety Authority and a NIOSH-funded CPWR hazard alert; see Sources below.
How to use it
Measure inside the mould. For a tray or coaster, enter length and width, then the depth of each pour. For a sphere or a shaped silicone mould, choose the water test and measure the water each layer takes.
Enter the ratio exactly as your product states it. If it says 1 : 1 by volume, measure millilitres; if it says 100 : 45 by weight, use a scale. The calculator shows both, converting with the densities you give, but mix the way the maker specifies. The extra covers what stays in the cup and on the stirrer.
Questions
Why do the resin and hardener weigh different amounts at 1 : 1?
Because they have different densities. ArtResin's resin is 1.135 g/ml and its hardener 0.967 g/ml, so equal volumes weigh about 100 : 85.
How thick can each layer be?
That depends on the product: check its maximum pour depth before pouring a thick layer, and mix each layer as a separate batch.
Where do I find my resin's density?
On its technical data sheet, or in section 9 of each part's safety data sheet, listed as density or specific gravity.
Sources
- ArtResin Inc., ArtResin technical data sheet (May 2018): mix ratio 1 : 1 by volume and 100 : 84 by weight; resin specific gravity 1.135, hardener 0.967; wear gloves and work in a well-ventilated area.
- Health and Safety Executive (UK), Health surveillance in the motor vehicle industry: epoxy resins are among the most common causes of occupational allergic contact dermatitis.
- Health and Safety Authority (Ireland), Epoxy Resins information sheet (2010): skin contact is the main route of exposure; irritation and sensitisation; gloves, goggles, labels and safety data sheets.
- CPWR – The Center for Construction Research and Training, Hazard Alert: Epoxy Resin Systems (2023, produced under a NIOSH cooperative agreement, on CDC Stacks): sensitisation; thick nitrile or butyl gloves, never cotton or latex; ventilation; washing hands.
- National Institute of Standards and Technology, Guide to the SI, Appendix B.9: conversion factors for inches, US fluid ounces and ounces.