If you’re a passionate resin artist, then you probably have an impressive collection of resin molds that you use to make beautiful jewelry or other creative projects. While working with molds is quite fun and simple, they should be cared for properly to extend their longevity.
Unfortunately, your resin molds are not going to last forever. They can wear out after repeated use, which is why it’s important to keep them clean and in good condition to save you the trouble of having to replace them.
How do you properly clean resin molds? There are several ways to clean resin molds depending on whether or not residue has been left behind. If the resin was fully cured in the mold, all you need to do is remove the resin object and wash the mold with warm water and dish soap.
In this article, let’s learn all about resin molds and how you can clean and care for them.
What Are Resin Molds Made Of?
To understand how to properly take care of resin molds, let’s first learn about what they are made of. There are two types of molds for casting resin: plastic and silicone.
1. Plastic Molds
Plastic resin casting molds are made from fairly flexible polypropylene or polyethylene sheet plastic. As a result, they are fairly inexpensive compared to silicone molds. Plastic molds are also easier to clean compared to silicone molds because de-molding is a lot easier compared to silicone molds.
However, there’s a reason why plastic molds are mainly popular among amateur resin crafters. The first is that plastic molds tend to dull your resin after it’s cured, so your creations may not look very shiny or polished after de-molding. This problem can easily be fixed with a gloss sealer, but it’s still quite inconvenient.
Plastic molds are also not very durable, so you may find scratches on your mold after a few uses.
2. Silicone Molds
For those who are passionate about resin art, it’s worthwhile to invest in silicone molds, which are made from two-part silicone.
Silicone molds are super flexible and durable, so de-molding is very straightforward, and you don’t have to worry about damaging the mold in the casting process.
You can also make your own silicone mold using two-part silicone, so it’s easier to make custom designs and let your creativity run wild.
When you use and care for silicone molds properly, your resin creations can come out very glossy and pristine, which is the reason why a lot of people who enjoy resin art prefer using silicone molds.
Of course, silicone molds are fairly expensive, and if you want to keep them functioning for a long time, you need to care for them properly. In the next section, let’s talk about how to care for your silicone resin molds.
Products To Use For Cleaning Resin Molds
While silicone molds require more care than plastic molds, you don’t need a lot of things to properly clean resin molds. Here are some products that we recommend.
1. Dish Soap
Yes, dish soap – the soap that you would use to wash your dishes every day. Dish soap is a highly effective degreaser, but it can also be a useful solution to use to help you remove any dirt or resin residue on your silicone mold.
When washing your silicone mold, it’s best to use warm water to gently loosen the resin without damaging the mold. While silicone can handle high heat, it’s not necessary to use hot or boiling water when you wash your silicone molds.
2. Mold Release Agent
Silicone molds are coated with a release agent during the manufacturing process that makes it a non-stick surface, which makes demolding super smooth and easy.
When the silicone mold is new, you will find that demolding is quite easy because the cured resin will come off right away without any issues.
However, after some use, the release agent can wear off, and as a result, the resin can stick to your silicone mold, making demolding difficult and even damaging both your creation and your mold in the process.
To prevent this issue, you should get a spray bottle of mold release agent and spray it on the inside of your silicone mold at least 10 minutes before casting. This will allow the silicone surface to become non-stick, which will then make de-molding much easier and help you avoid the mess.
How To Clean Resin Molds
When we talk about cleaning resin molds, there are a few things we’re talking about. You should clean your mold both before and after casting, and if there is some resin residue on your mold, there are a few extra steps that you should take to remove it properly.
Let’s take a look at each scenario below.
Preparing Resin Molds Before Casting
Did you know that you have to clean your resin mold before AND after casting?
This is because if your resin mold was left untouched for a while, dust and pet hair could settle on them. If you use them to cast resin right away, you can easily see trapped dust and pet hair trapped in the clear plastic after the resin is cured.
To avoid this issue, you should always wash your mold with dish soap and water before casting. After washing, you can wipe down the mold with a clean microfiber cloth and let the mold air dry for about half an hour before using.
After the mold is dry, you can spray the inside with a light coat of mold release agent, which will prevent the resin from sticking to the mold. After 10 minutes, you can safely use the mold to cast your resin.
How To Clean Molds With Resin Residue
An annoying issue that can happen when you don’t mix your resin with the right ratio is that it won’t cure properly, and as a result, de-molding can become frustrating, and your mold is left with sticky resin.
Don’t throw away your mold just yet, because there’s still a way to save your mold!
The first thing that you can try is to put your mold in the freezer for a few hours. The sticky resin will freeze to form a solid mass, and you can easily peel it out of the silicone mold (the silicone won’t freeze) afterward.
If there is cured resin residue on your mold, you can easily peel it away since it has hardened, and the silicone is flexible enough for the cured resin to pop out.
If the cured resin is a bit stubborn, you can soak the silicone mold in warm water (not boiling) for about 20 minutes to undo the curing process and soften the resin, at which point you can easily remove it from the mold.
How To Clean Resin Molds After Casting
After all the leftover bits of resin have been removed from the mold, you can simply wash the silicone mold with soap and water to clean it.
When washing your mold, you should not use any abrasive sponges or steel wool to scrub it, and don’t use any hard scrubbing motion in this process. These tools can easily scratch and even damage the silicone, which means you won’t be able to use it again.
When you wash your mold, you should also make sure not to stretch it out. While silicone molds are very flexible, they can still stretch under stress, so you should handle them with care to maintain their shapes for future castings.
After washing, you can leave your resin mold out to air dry before storing them. Some resin artists also recommend applying the release agent at this stage after washing to maintain the mold’s performance, but this step is optional.
For more details on cleaning silicone after molding, here’s a visual tutorial from Claire’s Craft Corner on YouTube.
Resin Mold Care Tips
In addition to the washing instructions above, there are a few things that you should know to keep your silicone molds brand new for future uses.
1. Keep Away From Fire
When casting resin, a common issue that you can have is trapped air bubbles inside the resin. In these instances, a heat gun is often used to pop the bubble from underneath the resin.
While silicone is very durable and can handle very high heat, you should still not use a heat gun with a silicone mold. The open flame can melt the silicone and tear it apart, which will ruin your mold altogether.
If you find that there are bubbles in your resin, there are plenty of ways to remove them without having to use a blow torch. You can warm the resin before casting and work in a warm room to minimize the bubbles. A hairdryer can also be used to pop bubbles without damaging the silicone.
2. Keep Away From Dishes
Silicone can withstand the heat of your dishwasher, so you can pop your silicone molds in the dishwasher. However, we would strongly advise that you wash your silicone molds separately from your dishes, which you’ll be eating out of.
This is because if there’s any tiny resin residue on your mold, it can become soft due to the high heat in the dishwasher, and it can get all over your dishes. Resin, especially when it is not cured, is toxic and not safe to consume, so you should always wash your silicone molds separately.
For the same reason, you shouldn’t use the same sponge to wash your dishes and your silicone molds. You should use a clean sponge to wash your mold, and after that, you should not use the same sponge to handle your dishes.
3. Be Careful When De-Molding
After your resin creation is cured, it’s time to de-mold. While silicone is very flexible, which can make demolding fairly easy, you should still go very slowly in the demolding process to avoid stretching out the mold.
For example, don’t turn the silicone mold completely inside out; instead, you should peel away the mold slowly. If you’ve used the release agent, the cured resin should be able to pop out easily without a lot of force, which can keep the silicone mold from stretching.
Don’t try to de-mold your resin before it’s completely cured. The curing time is a bit different for every type of resin, and you should pay attention to the product’s specification and only de-mold after the required curing time.
If you try to de-mold before the resin completely hardens, the resin can stick to your mold, which will ruin both your creation and your mold.
4. Don’t Use Alcohol To Treat Your Silicone Molds
There is a common misconception that you can use acetone or other stripping solutions to remove resin residue from your mold.
While acetone (nail polish remover), isopropyl alcohol (rubbing alcohol), and other stripping solutions are very effective at removing resin residue, especially when the resin isn’t cured properly, these solutions can also strip your silicone surface and damage it.
If you want to preserve your silicone mold, it’s best to stay away from these alcohol-based solutions and use the methods mentioned above to properly clean your molds.
5. Use Your Resin Properly
Resin comes in a two-part solution: a resin and a hardener. You will need to mix these two parts in equal proportions to activate the curing process before casting it into a mold.
Sometimes, if you don’t mix the resin properly or use the right proportions, it will not cure, resulting in tacky resin residue on your mold. So, the first step in protecting your mold is to carefully read the resin’s specific instructions so that the result will turn out perfect.
When casting the resin, you should also look at the casting instructions. Some resins are not designed for thick pours, and you can only pour up to ½ inches.
If you use a resin that’s not designed for thick pours on a deep mold, the resin also won’t cure right, creating a tacky residue on the bottom of the mold.
A thick pour can also overheat the silicone mold during the resin’s curing process, so you may also risk damaging your silicone mold this way.
Even if the resin is designed for thick pours, it’s still best to use controlled motions and use layers if you want to create a thick pour. This way, you can also prevent trapped bubbles and prevent any damage to the mold.
6. Store Your Mold Properly
After cleaning your mold, you can let the water air dry completely. It’s best to store your dry silicone mold in a sealed Ziploc bag so that dust cannot settle on them, which means they’re ready to go when you need them.
When storing your molds, it’s best to keep their original shape. You want to remove as much air as possible from the Ziploc bag without distorting the shape of the silicone mold. That way, you can maintain the shape of the mold for the next casting.
7. Wait Until The Silicone Is Cured Before Using
One of the reasons why resin artists love using silicone molds is that you can totally make your own silicone molds at home using two-part silicone. This process is really fun and simple, and you can make a mold for anything that you want to cast for your resin creation.
If you are making your own silicone mold, then make sure to follow the silicone’s instructions, especially paying attention to the curing time of the silicone so that you have a completely solid and dependable silicone mold before using it with any type of resin.
After making your DIY silicone mold, you should also trim away any thin parts in the silicone mold that can chip away or stick to the resin when casting. This way, your resin creation will come out perfect and unique.
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