You can make larger objects with UV resin, but you’ll need to work in very thin layers to achieve an even cure. [2] X Research source For instance, if you want to seal a large object with a layer of UV resin, you can apply a thin layer with a brush, then cure it under a UV light. For a project like this, you may need to use a large lamp or a handheld UV flashlight that you can move around over the surface of the project.
Some UV lamps come in the form of a hood or dome that you can place over the object you need to cure. If you’re using this kind of lamp, make sure it’s big enough to completely cover the object you’re trying to cure.
Test the resin with a toothpick every 2-3 seconds to see how hard it is. Depending on the size of the object, it might take around 2 minutes for each layer to cure.
Take care handling the object while it’s curing. Because of the chemical reactions taking place in the resin, it can become very hot.
Humidity can also prevent your resin from curing properly. [7] X Research source If you want to sun-cure your UV resin, choose a time when the weather will be sunny and dry.
Slow-curing epoxy resin can have certain advantages, depending on your needs. For example, it tends to be stronger and more water-resistant than fast-curing resin. It also gives you more time to work with the resin while it’s still soft. [9] X Research source
The water shouldn’t be boiling hot—hot tap water will work fine for this purpose. Don’t heat just 1 component and not the other! Your resin won’t cure properly if the elements aren’t the same temperature.
For small amounts of epoxy resin, you can measure out your components using medicine cups with mL markers. If you’re mixing up larger batches, it may work better to weigh out your ingredients on a scale. Use a wooden stick to thoroughly mix the components together. Thorough mixing will help ensure that the resin cures evenly. [12] X Research source Work slowly and gently to keep bubbles from forming. Use the recommended hardener that comes with your epoxy resin. Mixing and matching different products can affect how your resin cures.
Experiment with adding just a few drops of your pigment of choice to see if you can get the result you want. You can buy liquid pigments that are formulated to work with epoxy resins, or mix in some colored mica powder.
Check the packaging of your product for specific temperature guidelines. If you don’t want to heat your entire workspace, you can use heat lamps or a space heater to raise the temperature immediately around your project.
Using too much direct heat can cause your resin to bubble or crack, so watch closely and move the heat away immediately if you notice this starting to happen.
The curing time will also depend on the size of your project. Resist the urge to handle your project before the recommended curing time is over. Touching or handling the resin before it’s fully cured could cause smudging or bumps on the surface of your art.
Make sure to use a hardener that’s intended for use with polyester resin! This kind of hardener is called MEKP. If you use hardener intended for epoxy or some other kind of resin, it won’t cure properly.
A small amount of inhibitor goes a long way, so check the instructions carefully to determine how much you should add.
It takes about 15-20 minutes for polyester resin to reach the firm gel stage. If you allow a layer to cure completely before adding the next layer, the fresh resin will seep down into the mold around the shrunken first layer and give your piece an uneven appearance.
To ensure your resin doesn’t harden too quickly while you’re working, try to work in a space that’s around 65–70 °F (18–21 °C). You can increase the temperature or move the piece to a warmer space when you’re done. Since both room temperature and the amount of hardening agent will affect how fast your resin cures, you’ll need to factor in both of these variables when planning your piece. For example, if the instructions call for 4-5 drops of hardener per 1 fluid ounce (30 mL) of resin at a room temperature of 70–75 °F (21–24 °C), decrease the amount of hardener you use by 1 drop if the room is any warmer than that.
Smaller pieces, like jewelry elements, may cure in as little as 1 hour. [23] X Research source In general, you can safely handle your art once it reaches the “click hard” stage (i. e. , it clicks when you tap it and is no longer sticky).
For example, this might be a good option if you’re making some simple charms or pendants.
For example, some polyurethane resins require you to make a 1:1 mixture of resin and catalyst, while in other cases you only have to add a few drops of hardening agent to the resin. Mix your components thoroughly to ensure even curing.
If your resin needs heat to cure, you may need to turn up the heat in your workspace or warm your project with a heat lamp. Check the instructions with your product to determine the best temperature range for curing. Typically, “cold cure” polyurethane resin can cure at room temperature. You don’t need to chill it or reduce the temperature in the room—just leave it alone to dry on its own!
Don’t leave your polyurethane resin outside to cure unless you know conditions will be dry. Keep it out of direct sunlight since this kind of resin is also UV sensitive unless it has the right additives mixed in. If you want to add color to your piece, make sure you choose a pigment that’s compatible with polyurethane resin. Some liquid pigments might affect how it cures.
The amount of time it takes to cure will depend on your specific product and how large the project is. Avoid touching your resin while it’s still soft or sticky to avoid damaging the surface.
