There is nothing more exciting than when you get yourself some new fancy molds and and can’t wait to begin using them!
However it is important to care for your molds to ensure that they have a long live span and create the best replica’s for you. We have put together a collection of helpful tips to ensure that your molds live a long and happy life, hope you find it useful.
The first thing to note is that Molds are Perishable, they are not ever lasting and will eventually wear out even with the best of care. As they are used to create pieces The integrity of the mold will wear, especially if it has lots of little details, the better you take care of your Silicone Molds the longer they will last however overtime they will “dull” which means lose the sharp edges on the small details of the mold. It is important to note that this is completely normal and with proper care can be slowed significantly, but not stopped.
Mold Release Agent:
Silicone is non-stick base agent, much like the coating on a frying pan it is most effective when brand new. New mold works great for the first few uses but you will then notice that the mold becomes harder to remove or takes more time; generally speaking this is because manufactures use silicone mold release agent during the manufacturing process, this allows the item the mold is casting to be removed easily and without damaging the fresh mold. Mold release agent comes in liquid and spray form, depending on what you are molding will depend on what’s right for you. For smaller more intricate molds such as the dice molds and shaker molds use a liquid silicone release agent and apply a very thin layer 10 minutes before pouring any resin into the mold using a cotton wool bud to ensure you apply too much and all the small gaps are coated. Using a small amount in a thin layer will not only increase the lifespan of your mold but will also make the de-molding process much easier.
Soap & Water:
This is perhaps one of the most important rules of mold care – Keep your molds clean! Leaving glitter, excess resin and other items in your mold can over time become more difficult to remove. Look after your mold and it will last longer.
You can clean your mold before casting by using a small amount of dish soap and warm water, this be careful not to over stretch the mold when cleaning in small areas or you could damage it. Never use steel wool, scrubbing sponges, or anything abrasive like a toothbrush as this will cause tearing and scratching on the surface of the silicone and affect future casts. Damaged spots on the silicone mold can create untreated holes that material will adhere to and tear the mold when demolding your cast.
Using lighters, flames and heat:
While many guides and Youtube videos will tell you to run a torch or heat gun over your mold to remove excess air bubbles it is strongly recommended you do not. While silicone can handle hot temperatures created during curing they are not designed to withstand the heat created by fire.
Repeated uses of this method in the Silicone Mold will break down the silicone and eventually cause it to fuse to the Epoxy resin and damage it. Silicone can withstand over 200 degrees Celsius (400 Fahrenheit), lighter and torches can put out much much higher temperatures.
If you have air bubbles the best practice is to pour the resin in a separate container heat it and then pour into the Silicone Mold. Also pouring from height can help to remove air bubbles when casting.
So you have followed the above steps and you are now ready to remove your resin cast!
Some molds can have small gaps to remove a large resin piece, such as the dice molds. It is important that you not over stretch the mold when removing your pieces as this will lead to the surface of the cavity to become dull and begin to form tears that will shorten the lifespan of your mold.
We are going to use the sharp edge dice mold as an example here as they can be quite tough to remove. If you have used a mold release it makes the process significantly easier and we have found after applying a moderate amount of pressure on the bottom the dice pops out without much fuss, limiting the stretching time and causing less stress on the mold. If you have not used one then another method is to place the mold in hot soapy water and gently pull the edges apart while applying pressure to the bottom.
Once demolded, clean your mold with hot soapy water thoroughly and place somewhere warm to dry.
When using AB Epoxy Resin, depending on the product you do not want to pour more than 1/4″ to 1/2″ at a time depending on the products specifications. Some products are designed for pouring large quantities but not all of them and usually it is a specific type of resin.
If you pour too thick you risk boiling out your cast due to the exothermic reaction that occurs when the Epoxy Resin cures and will ruin your cast, as mentioned above, the molds are designed to withstand heat but there is a limit to this.
Too much resin means too much heat, also it can lead to the resin not curing completely due to the reaction being too hot and you could end up with a cast that is solid on the surface but liquid on the bottom.
“My resin is stuck in the mold!”
First of all, don’t panic. Take a deep breath and check a couple of things – first check that the cure time , has it been long enough? Also be aware that the temperature of the room it is being cast in can affect the curing time. If you are casting in a room that is cold then this can significantly increase the resin cure times.
This is the most common cause and waiting longer for the cure and increasing the temperature does the trick. If the cast is still being stubborn
throw the mold in the freezer for 30-60 minutes, this will not cause any damage to the mold and should make demolding a lot easier. If you are having no luck and all seems lost, very careful take a craft knife and move it around the mold between the resin and the silicone, this allows air to get into the mold and can release the resin, however this should be the absolute last resort as it can cause damage to your mold.