The Beginners’ Guide to Aqua Cast Eco Resin Casting
I've been spending the last few months doing a deep dive into the world of aqua cast resin. Aqua resin goes by many names. Some people call it Aqua resin, others might refer to it as eco resin, jesmonite, setinstone, resincrete and Mix2Mold.
Different brands have different names and characteristics. I love working with aqua resin. The opportunities to be creative are limitless. Let me break it down for you.
What is Aqua Cast Resin?
Aqua cast resin is an environmentally friendly resin made from a fusion of powder (gypsum) and water-based liquid. Aqua Cast resin is not the same thing as epoxy resin or other traditional resins. Aqua resin is made from gypsum and closely resembles flour. It is mixed in a similar fashion to plaster, but it cures much quicker than plaster. Aqua resin can be used in molds and takes on an ultra-smooth finish. You can add color to aqua resin, both in the liquid form as well as the powdered form. Some brands use powder combined with water while others mix the powder with an acrylic liquid (similar to the medium used in acrylic paint) to create an acrylic resin. The environmental impact is lower for aqua resin than traditional petroleum-based resins—we love sustainable solutions!
Aqua cast resin cure times depend entirely on the brand. Some have more work time and more cure time, while others are quicker and you have to work pretty fast. It is much less dusty and chalky than plaster and cures much faster. It doesn't get as hot during curing and hardens with a porcelain finish. This is what I love most about it. It is not entirely shatterproof, but it is very strong and sturdy after about 72 hours and sealing.
Some people like to describe aqua cast resin as porcelain plaster. I like this description because it accurately describes the look once it reaches a full cure. The surface finish is very similar to that of plaster. While each brand has its own unique formula, they are all based on using grams of powder and water.
What Can You Make with Aqua Cast Resin?
Aqua cast resin has a wide variety of applications because it dries very strong. Here is just a small sampling of what you can create:
soap dishes
home decor
sculptures (you can mix in fiberglass and/or acrylic polymer additives to make it stronger)
candle holders
charcuterie boards
homewares
detailed figurines
ornamental vases with intricate designs
Key Features of Aqua Cast Resin
Dries quickly
No odor
Non-toxic
Sustainable materials
Easy to work with
Can be made into a food safe object
Works very well with pigments
Broken pieces can be broken back into shards and used againChoosing the Right Plants
Materials you'll need to get started
You’ll need:
Eco Resin (there are many brands to choose from)
Scale (optional since the measuring process is a bit more forgiving)
Mixing sticks (I love the jumbo popsicle sticks)
Sandpaper (grits 80, 400, 600)
Buckets and mixing bowls (I typically use old sour cream and cool whip containers)
Drill with shear mixing attachment (optional)
Colorant (liquid)
Mica colorant (powder)
Sealant (it also comes in a matte finish)
Plastic table covering
Garbage bags
Safety goggles (to use for sanding)
Optional materials include:
Glitter
Paint
Before you get started with aqua cast resin, please note that it is quite messy. Before I got started I noticed that almost all of the online tutorials made it look neat and clean. It is both dusty and messy, but cleans up easily.
How to Use Aqua Cast Resin: Step-by-Step
Follow these basic steps to get started with Aqua Cast Resin. While each resin brand may have specific instructions, these general steps will guide you through the process.
1. Prepare your workspace
I like to cover my table with plastic sheeting. Once the table is covered, I lay out a silicone baking mat. This is an optional step but I find that it is much easier to clean a silicone mat instead of cleaning plastic sheeting.
Put on some gloves and put on your mask. While aqua cast resin is non-toxic, it is still a dusty powder and shouldn't be inhaled. Wear a dust mask during the mixing stage.
2. Mix the resin and hardener
Each brand of aqua cast resin has different mixing ratios. For example, when working with Mix2Mold (see my full review here), the ratio is 3:1 powder to liquid. Here's how to mix:
Measure the powder. Do not worry if your measurements are not completely accurate because aqua cast resin is very forgiving. This is a key difference between epoxy resin and aqua resin.
Measure the water.
Pour the powder into the liquid, not the other way around. While this might seem like it doesn't make sense, this is the proper way to create a mixed solution and the desired viscocity.
Once the powder and liquid are mixed together, you can use your drill with the electric mixing blade or paddle for about 10-15 seconds to eliminate any lumps. Do not over mix because the solution will begin to cure more quickly. Once you've got the desired viscosity, you can begin pouring.
*remember: each standard aqua cast resin brand has its own handy online calculator, so make sure to do the research prior to starting. Each brand is mix ratio dependent so it is not a one size fits all formula.
3. Add color or pigment
If you are choosing to add resin pigments to your aqua cast resin, there are different ways to do this. My favorite way is to add it to the mixture before they are integrated together. By this I mean that you can add powdered pigment to the powder component or you can add liquid pigment to the water or liquid component (depending on which brand you end up choosing). This way, you have full control over your pigment without having to worry about the mixture curing before you're able to get it all mixed - some brands, like Mix2Mold cure pretty quickly. If this happens to you, simply make an addition of water (just a small amount) to the mixture. The water ratio will be off, but the water will end up evaporating anyway.
If you do not have your desired shade after both parts are thoroughly mixed, you can go ahead and add some more. You do not want to use too much pigment to get your desired colour shade because this might throw off the balance of liquid and powder. Each brand has its own recommendations as to how much pigment can be added for vibrant castings, so please do your own research.
Aqua cast resin can also be painted. If it is freshly cured, consider using acrylic paint. If it has been cured for some time, you can also use oil paints since aqua cast resin is a very porous material prior to curing.
4. Pour the resin into molds
After your resin is well-mixed and colored, pour it into your mold. To avoid too many pockets of air or residual bubbles, you can do one of two things:
Pour from several inches above the mold. Why? This is called needling and it creates a much thinner stream of liquid as it fills in the volume of your mould. While bubbles are inevitable, this makes it a little less likely to form.
Use a strainer. Pour your mixture through a strainer to ensure that you have no bubbling. This is something you might consider if you end up wanting to sell your aqua resin pieces.
5. Remove air bubbles
Once your mold is filled, you will want to tap the sides of the mold to eliminate any bubbles. As you tap the sides, you'll see the bubbles rise to the top of the mold. Once the air release is complete and you no longer see any bubbles, leave the mold untouched at room temperature so that it can harden and cure. It will feel like it cures at lightning speed!
6. Let it cure
Leave the aqua resin molds to cure for about 60-90 minutes depending on the brand. Some brands cure much quicker while others take more time. Once you reach 24-48 hours, you will have an excellent cured strength and while aqua cast resin isn't immune from breakage, it is a pretty strong material.
During the curing process, the aqua resin will have a chemical reaction and will warm up as it cures, which is very similar to both epoxy resin and plaster.
7. Demold
After a few hours, demould your piece. Many brands recommend that you demold your piece while it is still warm for best results. I don't always do that, but it's a good idea not to leave it in the mold for too long or it may develop some white spots on the surface.
8. Sand
Once the piece has cured for at least 24 hours, you can begin sanding your piece. I like to use an electric sander at the grit of 40 or 60 and then move on to finer grits until you've achieved the desired outcome. I have found that it is much easier to do a wet sanding rather than a dry sanding to achieve. It is sometimes hard to find the 40 grit sandpaper in wet/dry. If this is the case, be sure to use a coarse grade sandpaper or an abrasive pad. This is especially necessary if you are creating the terrazzo effect (see below).
IMPORTANT: Be sure to protect your work surfaces while sanding and wear a mask and goggles to protect your eyes.
9. Seal
Seal the piece for a glossy finish. There are two ways to seal the piece:
Food safe wax
Varnish - each brand has its own version of varnish, so experiment to see which works for you. I like the Mix2Mold varnish kit because it comes with everything you need to get started.
FAQs
What other names are used for aqua cast resin?
Eco resin, jesmonite products, hydroflow eco resin, jesin and the list goes on. It seems that there are new product releases all the time so look out for special offers.
What happens if I add too many ml of water?
Don't worry too much because the remaining liquid will eventually evaporate and it might only have an effect in terms of drying time, etc.
What kind of dry powder pigments do you recommend?
I think you should try and test out different products and see which work best for you. I really like the jesmonite and alluminite brands of liquid pigment for ease of use. For powder, I like most mica powders and bought these because they came in a variety pack. I am a total sucker for a variety pack!
What else can I add to my eco resin/aqua resin?
Experiment! I love how glitter looks! I have also tried using 3D stickers, epoxy resin and fabric. Play around and see what you can make!
Can I make larger projects with eco resin as well?
Yes! You can make so many different products with resin and they don't all have to be super small castings.
How to create the terrazzo effect using white eco resin
In order to attain the terrazzo effect, you will want to mix aqua cast resin with some mica powder (you can use pearlescent pigment powders or bright colors). Knock yourself out - if you want to make a tint max neon powder, do it! This should be a fun process. The more you decide to create, the more you will develop your very own style. If you do decide to add pigment to your eco pour, be sure to use a mixing container that is reserved for color.
Small terrazzo
Once your color is thoroughly mixed, spread it onto a piece of plastic. I like to do this on top of a ziploc bag. Once the aqua cast resin is fully cured, you can roll it up and crush it into little shards. These can be embedded into a liquid mixture to create new pieces. Just remember that terrazzo pieces will need a bit more sanding then the other items you might make.
Large terrazzo
If you happen to break a piece, do not worry. You can reuse them! This is one of the reasons why it is called eco resin. There is literally no waste! Use a hammer and break up the shards and place them like a mosaic onto the bottom of a mold. Pour the eco resin on top. Demold and sand like you would with other pieces.
Tips for Beginners
Work Slowly: Resin can be tricky if rushed. Take your time when mixing and pouring.
Start Small: Begin with smaller projects like keychains or coasters to get the feel for the process before attempting more complex pieces.
Avoid Humidity: High humidity can affect the resin’s curing process, so try to work in a dry environment.
Safety Perspective: Even though Aqua Cast Resin is non-toxic, always wear gloves and work outdoors or where indoor ventilation is good.
Aqua Cast Resin is an accessible and enjoyable medium for anyone looking to explore the world of resin art and crafts. It is low odor, non-toxic, and so much fun to work with. You do not need prior experience when working with eco resin - the instructions are so easy and you're sure to end up with professional-looking results. You'll be hooked in no time! Happy crafting!
