FAQ
Epoxy Resin
How much time does it take to cast ?
1.Working time: The working time for making the resin is 40 minutes, after mixing for more than the working time, the resin will start to solidify and become too sticky to pour or spread, and it is impossible to remove air bubbles from the resin.
2. Demoulding time: It takes 8 hours to demould the resin.
3. Curing time: It takes 24 hours to dry and cure completely, the curing time is affected by the thickness of the casting and the temperature.
4.Temperature affects the working time. Working in hot weather reduces the working time of the epoxy resin, causing it to overheat and accelerate curing in the mold.
Why is the resin not cured?
1. Incorrect mixing ratio before using the resin, please make sure the mixing ratio is correct.
2. Insufficient mixing.
3. Too much colorant or filler, it is recommended not to fill more than 6% of the casting volume.
4. Insufficient cure time.
How to reduce bubbles in epoxy resin?
Resin sticking is usually caused by inaccurate measurements, incomplete mixing and low temperatures. Temperatures below 15°C/59°F heat part A resin to 30°C/86°F before mixing with part B hardener.
How do I deal with air bubbles after pouring?
1. Stirring should be done at an even speed in the same direction. Rapid mixing of the resin will produce a lot of air bubbles.
2. Pierce the bubbles on the surface with a toothpick or the tip of a mixing stick. If you can't poke the bubbles, use a lighter to move the flame quickly on the surface of the resin to remove the bubbles with high temperature.
3. Run a toothpick or the tip of a stirring rod along the bottom edge of the mold to remove any air bubbles between the side walls and the bottom of the mold. This way, there will be no holes in the front edge of the mold when you demold it.
Thermal Reaction of Epoxy Resin
Mixing epoxy generates heat, the more you mix, the higher the temperature and may smoke and then cure.
Store curing epoxy in a safe and ventilated area to prevent injury from accidental contact
Environmental Factors Affecting Epoxy Resin Curing?
Humidity:
If the humidity is greater than 85%, the surface of the cured mixture will absorb moisture from the air and form a white haze, therefore, if the relative humidity exceeds 85%, this is not suitable for room temperature curing and heat curing is recommended
Temperature:
If the temperature is below 15°C/59°F, heat to 30°C/86°Fbefore mixing because the lower the temperature, the more viscous the resin in PartA becomes
Tips for Pouring：
Avoid working with large batches. The more resin you mix, the more heat it generates, which can cause a flash cure (the resin hardens within minutes).
Do not pour more than 200 ml at a time.For deeper molds, pour in multiple layers, waiting 3–5 hours between each pour.
Do not cast layers thinner than 3 mm, otherwise the resin may not cure completely.
How to Reduce the Formation of Bubbles
1. Slowly and thoroughly mix Part A
Stir the resin slowly in one direction for at least 3 minutes.
Avoid rapid stirring to prevent air bubbles.
Scrape the sides and bottom of the container to ensure both parts are fully blended.
2. Let the epoxy resin rest before pouring
After mixing, let the resin rest for 5 minutes. This waiting period helps trapped air bubbles rise to the surface.
If necessary, use a heat gun or spray gun to gently remove surface bubbles before pouring. Alternatively, use a sharp object (like a toothpick) to pick out or puncture bubbles.
3. Pour Slowly
Pour the resin slowly into the mold, starting from one corner. Allow the resin to flow naturally to fill the space and minimize bubble formation. Avoid pouring from a height to prevent trapped air.
Liquid Silicone Rubber
Can I color the translucent silicone?
You can add mica powder or silicone rubber pigment specifically for silicone rubber. Do not adding too much colorant or cure inhibition may occur.
Why does silicone exhibit stickiness or remain uncured?
1. Inaccurate mixing ratio or insufficient mixing.
2. Inadequate curing temperature or insufficient curing time.
3. The working environment, containers, or master molds contain materials incompatible with liquid rubber silicone, causing a suppression reaction in platinum-cured silicone.
UV Resin
How to Remove Bubbles from UV Resin ?
Causes of Bubble Formation:
High Viscosity: The thicker the resin, the more likely it is to form bubbles when extruded from the nozzle.
Low Temperature Environment: Cold temperatures increase resin viscosity, making it harder for bubbles to escape.
Solutions
Slowly extrude UV resin to minimize trapped air. After pouring, gently prick visible bubbles on the surface with a toothpick or silicone rod. Alternatively, lightly heat the resin surface with a heat gun or small spray gun—the warmth helps trapped bubbles rise and dissipate.
⚠️ Never overheat. Excessive temperatures may cause premature curing or yellowing of the resin.
Can mica powder be brushed onto the mold surface before pouring UV resin?
The resin will most likely fail to cure properly. First, pour a layer of clear UV resin and cure it under a UV lamp. Then brush the powder onto the surface and pour another layer of clear resin to cover it.