How to measure and mix epoxy resin and hardener in five easy steps

How to measure and mix epoxy resin and hardenerEpoxy resin comes as a two part system:  the Part A resin and the Part B hardener (also known as a catalyst).  Knowing how to measure and mix epoxy resin and hardener is important to making sure your resin cures as expected!  Here are the steps to make sure you have resin curing success every time.

Step 1

Clearly understand the mixing directions of the epoxy resin you are using.  Not all resins mix the same! 

resin mixing instructions

It’s important to note several things when mixing epoxy resin and hardener:

*Does it mix equal parts A and B or does it mix two parts A to one Part B (or perhaps even something else)?
*Does it mix by weight, volume or either?
*What are the minimum and maximum mixing amounts of the resin?

These resin mixing instructions are important to making sure you get the resin curing results you want.

For the resins sold on Resin Obsession, you can find all that information in this article:  Resin casting kit choices

Step 2

Determine the total volume of mixed resin you need for your project.  From there, break it down into the amount of Part A resin and Part B hardener you need to mix together.

For example, let’s say you are working with a resin mold that needs 1 1/2 ounces of resin and you are using the Resin Obsession super clear resin.  This resin mixes 2 parts A to 1 part B by volume, so you will need 1 ounce of Part A and 1/2 ounce of Part B.

Not sure how much resin and hardener you need to mix?  Here’s how you figure out how much epoxy resin you need to mix for a project

Step 3

Gather the resin supplies necessary to make sure you get accurate measurements on your epoxy resin and hardener.  Make sure your resin work area, along with your epoxy resin and hardener, are at the ideal temperature.  You can learn more about that here:  What is the best temperature for working with resin?

resin mixing cups

One ounce and ten ounce graduated mixing cups are an easy way to accurately measure your resin kit components.

Pro tip:  You may see other people using their resin kit lid caps, plastic drinking cups, kitchen spoons and other miscellaneous items to measure their resin.  I’m sure that works — at least part of the time.  When I’m troubleshooting resin curing problems, oftentimes it comes down to someone not measuring their resin kit components accurately.  The best way you can do that is with graduated measuring cups designed for epoxy resin.

Of course we can’t ignore resin safety here either.  At a minimum, you need to wear gloves and work in well-ventilated area.  You can get my other resin safety tips here:  how to use epoxy resin safely.

Step 4

Now it’s time to pour your resin and hardener into separate cups.  Measure exactly and resist the urge to add extra hardener.  Doing this makes your resin heat up too quickly and shortens the pot time of your resin.

measuring epoxy resin and hardener into graduated resin mixing cups

Pro tip:  Why use separate cups for the two components?  In case I overpour either the epoxy resin or the hardener, I can pour it back into its respective bottle and not waste it.

My other pro tip:  Pour from one bottle, then recap before pouring from the other bottle.  If you uncap both bottles at once, you risk switching the lids.  You don’t want to cure your bottles of epoxy resin and hardener shut.

Step 5

Pour the two parts together and stir well.  Scrape the sides of the cups and your stirring utensil several times during the process.

Like this post? You may be interested in  What I wish I would have known about making things with resin before I got started.

You will likely notice your resin having a wavy appearance when first mixing the two parts.  This is normal.  The mix should go clear when you are done combining.

Here’s an example:

waves in epoxy resin and hardener

This is what the Resin Obsession super clear resin looks like after mixing the resin and hardener for about 15 seconds.

clear epoxy resin - Resin Obsession

This is what it looks like after stirring for two and a half minutes.

Pro tip:  My rule is to mix the resin for ten percent of the resin’s pot time.  If I’m working with a resin with a thirty minute pot time, that means I will mix the resin and hardener together for three minutes.

If you like to reuse your resin supplies, then you will love that you can clean your resin mixing cups for another use.  Here’s how:

Note:  While it’s always best to stir your resin in a way to prevent bubbles, sometimes it is unavoidable, especially if mixing large volumes.  It is always better to thoroughly mix your resin and remove bubbles later with a heat gun rather than undermixing to avoid bubbles.  Undermixed resin will not cure.

Now you are ready to use your resin!

Cast as desired and wait for your awesome resin project to come to life!

And one more pro tip:  Once you start this process, set a timer.  It is a great reminder to focus on what you are doing and not lose track of time.  You want to get all your resin used before it starts to cure!

Here’s how to measure and mix epoxy resin and hardener for resin jewelry, crafts and resin art purposes in under three minutes:

What other questions do you have about how to measure and mix epoxy resin and hardener?


Unpublished Blog Posts of Resin Obsession, LLC © 2019 Resin Obsession, LLC



If I am putting pieces of brick in my resin do I need to do anything to the brick first? I just usually spread the pieces around in the mold and then put a laminated picture on top of brick and resin!! Then I pour more resin over the picture and brick! Is this the best way! Then I take a torch gun and try and get most of the bubbles out! Then let cure for a day and a half!!! Sometime coasters are sticky!!! Any suggestions????


Hi- sometimes my resin drys wavy. What could be causing that. It does dry hard. Thanks!


I find measuring by volume open to mistakes, especially when doing small projects, is it possible to use by weight instead, I use Clear Cast. Thanks ,Julian

Katherine Swift

Hi Julian, I haven’t used that brand. You will need to ask them if measuring by weight is appropriate for what you want to do.


Leave a Reply

Your email address will not be published. Required fields are marked *