If you think you’ve mixed it enough, mix it again.
Each brand of resin has different properties and mixing ratios. One of the resins I like to use is produced by the company Art Resin. It is a 2-part epoxy resin, and it has a nice mixing ratio of 1:1. I won’t lie, I’ve never used a 2:1 ratio mainly because I’m scared I’ll do the math wrong and mix up a useless batch. Plus, I’m really happy with the Art Resin brand and it’s high-gloss properties (amongst other things).
In any case for mixing resin you’ll need:
- Butane torch or heat gun
- Respirator — make sure your find cartridges that are good for filtering out organic vapors
- Measuring container (dollar store ones work great)
- Something to stir the resin with (paint stir sticks work great too)
Side note: Art Resin says there are no VOC’s in their resin therefore no need for a respirator… but I like to be safe. 🙂
So, first you need to figure out how much resin you need. As an example I’ll use an 8in x 10in area with a 2 mm desired thickness for the resin. I find it easier to do the math in cm to find out what I need in mL.
20.3cm x 25.4cm = 515.6cm
515.6cm x 0.2mm = 103.1 mL
Now, the 103.1 mL is the total amount of resin you’ll need to cover that area, but because we’re using a 2-part resin, you’ll need to divide the total amount needed by 2 in order to get the amount needed for each part.
103.1 mL / 2 = 51.6 mL per part.
I also like to round up to the nearest 5 mL to take into account any resin that gets left over in the container after pouring, or on the stir stick. It’s often better to have a bit too much, than not enough.
Voila! There’s the math for a 1:1 ratio.
On to the mixing…
Now that you’ve done the math you’re ready to mix! Put your gloves on first! Then in a measuring container, pour in the required amount for each part. Be careful not to pour too quickly, as it can sometimes take the resin a bit to level out, and you might end up pouring too much out. After you’ve poured equal parts, it’s time to mix! Take that stir stick and mix, mix, mix! The resin will often become cloudy before turning clear again once the resin has been thoroughly mixed. However, just because it’s clear and you think the resin ha been mixed, definitely mix again! I have had a few occurrences where I didn’t mix the two parts together well enough and ended up with a half-cured, sticky, pour… that I just ended up scraping off. Let me tell you, it’s no fun at all. So, depending on how much you’re mixing, give it a good 3–5 minute mix. For bigger batches definitely add some mixing time on to that.
Once you’re satisfied with your mixed resin, it’s time to pour! Keep in mind to not scrape the sides as you pour — unless you scraped the sides while mixing to ensure all that unmixed resin got mixed in. But if you didn’t, chances are you’ll have just scraped unmixed resin into your well-mixed resin and it won’t cure properly.
Once you’ve poured out your resin onto whatever surface you used, be sure to get the air bubbles out via butane torch, or heat gun, and find something to cover your piece while it cures, essentially stopping any dust or debris from getting into your piece.
And that’s it! All done!
I tweeted a quick video of mixing 2-part resin. I realize however that it’s not a very good video as the mL are facing away from the camera, so you can’t see how much I’m pouring, and the giant $1.50 sticker is really unappealing. Hah. This video was simply to document that I am capable of mixing resin for my passion project.😛