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Frequently Asked Questions
What factors affect epoxy cure?
Individual resin systems are formulated to have an appropriate reactivity level for their end application. However, other factors play a role in how an epoxy cures. These factors are listed below:
Mix ratio – Follow the mix ratio closely. Keep in mind volume and weight ratios are different. Inaccurate mixing is a common cause of cure-related issues.
Inadequate mixing – Mix the product for the recommended duration. Make sure to scrape the sides and bottom of the container during mixing. Ensure product is clear and streak free before use. Do not scrape the container when pouring. Unmixed resin can result in soft or tacky areas of uncured resin on your project.
Ambient conditions – Resin will cure faster in warmer conditions and slower in cooler conditions. At the extreme, working in areas that are too warm or too cold can result in overheating or failure to cure, respectively. Follow the recommendations for working temperatures in the product’s Technical Data Sheet.
Temperature of your resin and hardener – Similar to ambient temperature, warmer products will react more quickly than colder products.
Project size or volume – Larger or higher volume projects will generate more heat and will cure faster. These projects have the potential to overheat and should be monitored during cure. Lower volume projects will be slower to cure.
- Ability of your project setup to shed heat – Due to the resin system’s chemistry, it will generate a certain amount of heat to complete the cure. These formulations are tailored to cure as fast as possible while avoiding overheating. The ability to shed heat is related to the surface area of the project relative to the volume of resin used. Additionally, the mold or mold material will insulate the curing resin and may play a role in overheating.
Why didn’t my epoxy cure?
Listed below are a few possible causes of why an epoxy project doesn’t cure:
- Wrong mix ratio – Too much resin or too much hardener will result in unreacted product left that cannot form cross-links. This can result in a project that is tacky or a soft cured epoxy.
- Poor mixing – Poor mixing can result in uncured resin. This can affect the entire project or be localized to small areas that remain tacky. Even with careful mixing, some areas of the mixing cup may have remnants of unmixed resin and hardener. This is why we recommend that you do not scrape the sides or bottom of the container when pouring, to get every drop.
- Temperature is too low – If the ambient conditions or epoxy temperatures are too low, the chemical reaction necessary for curing the liquid epoxy to a solid will be slow to start. Consult the product’s Technical Data Sheet for recommended working temperatures.
- Insufficient resin mass – Most casting resin systems rely on the generation of heat from the reacting resin to complete the curing process. If there is not enough reacting resin generating heat, the cure will proceed extremely slowly.
How does volume affect resin cure?
Heat is released during the chemical reaction that converts liquid part A and part B into solid epoxy. The amount of heat released depends on the epoxy’s chemistry and the amount of epoxy used. That is, a certain amount of mixed part A and part B will result in the release in a certain amount of heat.
The curing epoxy must be able to shed the heat it generates efficiently enough to avoid overheating. The ability to shed heat is largely governed by the ratio of top surface area that is open to the air relative to the volume.
For the same resin system, thinner castings will have greater top surface areas in comparison to overall volume and will shed heat more efficiently. Thicker castings cannot shed heat as efficiently and may overheat.
For the same volume of epoxy, a thinner casting will have a larger top surface area and will shed heat more efficiently compared to a thicker casting with a smaller top surface area.
How volume affects exothermic reactions
EcoPoxy systems are developed to have reactivity levels suited to their intended applications. Always consult your product’s Technical Data Sheet or Application Guide for recommended volume and thickness.
Why did my epoxy overheat and turn yellow?
How do I dispose of epoxy resins and hardeners?
Cured epoxy resin is inert and should be disposed of as you would other solid non-hazardous waste. Uncured resin, or residue left over in jugs, must be disposed of properly as the hardener and resin are unreacted. If the jugs have been sufficiently drained, they may be recycled but the amount of allowable residue will be determined by your local hazardous waste collection center and the prevailing regulations. When contacting your local waste collection center, you will need the Safety Data Sheets that are available for download from our website.
Are epoxies biodegradable or recyclable?
During the curing process, epoxy resins and hardeners form crosslinks that cannot easily be broken. Technologies are being developed to break down these types of plastics for recycling, or via other biodegradation methods, but none are readily accessible. Practically, this means that all epoxy resin systems are neither biodegradable nor recyclable.
How should I store my resin and hardener?
Store in a cool, dry, well-ventilated location out of direct sunlight. Protect from freezing and physical damage. Do not store in a location subject to frequent temperature changes as the product may crystallize. Use product as soon as possible after opening. If storing remainder of product for another project, keep container tightly closed. Recommended storage temperature is between 15-25°C (59-77°F).
What is the shelf life of EcoPoxy products?
EcoPoxy products are good for 2 years in an unopened container. Once opened, part A and part B should be used within 3 months. Avoid mixing part A and B from old and new batches.
What do I do if I see crystals in my epoxy?
Over time, crystals can develop in epoxy resin (part A). This can cause your resin to appear cloudy and eventually solidify. Resins with signs of crystallization should be heated to remove the crystals before use.
To heat the resin, bring a water bath to 50°C (122°F) and place the jug of resin inside. Do not submerge the jug. Do not heat resin above 50°C (122°F). Resin should be heated throughout; otherwise, remaining crystals will cause recrystallization. For larger volumes, hold resin at 50°C (122°F) for 1-3 hours, for smaller volumes, less time is required. Do not leave any EcoPoxy kit at elevated temperatures for longer than 8 hours.
When you remove the resin from the heat, it will be at an elevated temperature. If the resin is used immediately, it will cure faster and have a shorter working time. In some applications, this can result in entrapped air. We recommend allowing the resin to cool to 20-25°C (68-77°F) before beginning work. Working times for these conditions will be closer to that specified on the product Technical Data Sheet.
What is the bio-based content of EcoPoxy products?
EcoPoxy works hard to increase bio-based materials in individual products and source more raw materials from annually renewable resources instead of petroleum-based sources. Our products are tested for bio-based carbon content by a third-party tester (ASTM D6866). The test method evaluates the percentage of carbon content from bio-based sources relative to total organic carbon content in the system. Bio-content varies across the EcoPoxy product range and can be found on our products’ Technical Data Sheet.
Are EcoPoxy products recommended for outdoor applications?
We do not recommend our clear casting and coating resins for outdoor applications even when they are pigmented. Keeping epoxy projects outdoors can result in issues with discoloration from UV light, water marks from moisture exposure, and separation and cracking from thermal expansion and contraction with temperature changes.
Will my epoxy project yellow over time?
All epoxies yellow over time due to the ultraviolet component of natural daylight. To combat this, we often formulate our products with UV stabilizers, especially those that are used as transparent or translucent systems. UV stabilizers absorb UV light and prevent damage to the resin. Eventually, the stabilizers will lose their effectiveness. Adding metallic or liquid pigments to epoxy will help it resist yellowing better than if it is left transparent. Completed projects should not be kept outdoors.
What are UV Stabilizers?
All epoxies yellow over time. To combat this, we add UV stabilizers to some of our products, especially those that are used as transparent or translucent systems. UV stabilizers absorb UV light to prevent damage to the polymer but are consumed in the process. Over longer periods of time, the absorbers lose their effectiveness. Discoloration will happen over extended periods of UV exposure even if you pigment your epoxy, though it will be less noticeable.
Are EcoPoxy products food safe?
EcoPoxy products are not FDA compliant for direct contact with food.
Can EcoPoxy products be applied in multiple layers?
Yes, EcoPoxy products can be applied in multiple layers. However, each resin system is formulated to have a different reactivity level to be suitable for a certain type of project.
We recommend you consult your product’s Technical Data Sheet for recommendations on working temperatures, application thickness, or maximum volume for each layer. Consult your product’s Application Guide for advice on how to do multiple layers.
Also, keep in mind other factors that affect cure. These include resin volume and geometry, the temperature of the resin and hardener, ambient conditions, and the ability of the mold to release heat.
Is there a difference between glitter, metallics and liquid pigments? How much should I add?
EcoPoxy has three different pigment product lines; Liquid Color Pigments, Metallic Pigments and Color Glitters. Each are available in a variety of colors and each creates their own unique effect. To decide on the pigment line needed, first you will need to determine the effect you are going for.
- Liquid Color Pigments are used to attain a uniform opaque or translucent color effect.
- Metallic Pigments are a fine metallic powder that creates a multidimensional pearlescent or iridescent effect.
- Color Glitters are different from metallic pigments. They are larger flakes of colored glitter that settle to the bottom of the epoxy.
Consult your product’s application guide or product webpage for how much of each pigment to add to achieve the desired effect.
What mold materials are compatible with EcoPoxy’s casting resins?
If you choose to build a mold, we recommend using melamine, medium density fibreboard (MDF), or smooth plywood for the base and walls. Visit EcoPoxy’s support website for the tutorial on how to build your own casting mold. If you are wondering about other materials for your mold surface, see below for a list of materials that epoxy will and will not stick to.
Epoxy will stick to:
Epoxy will not stick to:
- EcoPoxy Epoxy Mold Release Tape
- High Density Polyethylene (HDPE)
Pre-made molds are available from epoxy or other woodworking stores. Follow manufacturer instructions for surface preparation prior to casting.
How do I prep my mold for use with EcoPoxy products?
Mold or surface preparation varies depending on your mold type. However, it is important that all molds are clean, dry and free of contaminants.
When building your own molds out of MDF, use a sheathing tape, applied to the surface prior to final construction. Once assembled, seal the edges and corners with silicone caulking. Mold release is not necessary for this type of mold.
When building your own molds out of melamine sheet, seal the edges and corners with silicone caulking and apply a mold-release paste wax to ensure easy demolding.
For HDPE molds, mold release is not necessary. However, using a mold release is good practice to extend the life of your mold.
Silicone molds are less durable. Using epoxy will degrade the surface of the silicone mold over time. We recommend using a spray on mold release, applied to the manufacturer’s specifications. Test the compatibility of your release product with the epoxy prior to starting.
What surfaces can be coated with UVPoxy?
UVPoxy will adhere to most surfaces. UVPoxy can be applied as a high-gloss topcoat over epoxy, wood, glass, ceramics or metals. Abrade glossy surfaces for better adhesion prior to cleaning and coating. UVPoxy can also be applied over various substrates such as wood panels or pre-made canvases to make fluid art. When applying over fabric canvases reinforcement may be necessary to prevent sagging.
Plastic items can be coated with UVPoxy. However, when applied to a flat surface UVPoxy will not generally adhere to the following materials:
- EcoPoxy Epoxy Mold Release Tape
- High Density Polyethylene (HDPE)
- Polyethylene (PE)
- Polypropylene (PP)
Can epoxy be applied over wood stain?
Epoxy can be applied over many wood stain products. However, if the stain is oil-based and not fully dry, there may issues with fisheyes, cratering, and contamination. Regardless of the type of stain, a clean rag, rubbed on the stained wood, can identify whether or not the stain is dry. If the stain is dry, it will not show on the rag. Some stains can take more than a week to fully dry.
If you plan to use epoxy over a stained surface, it’s best to try coating a small test piece first. This will prevent costly mistakes on your actual project. You may also want to consider seal coating your stained wood project to avoid bubbles.
How do I prepare surfaces for coating or application of additional layers?
To prepare surfaces for coating, follow the steps below:
- Abrade the surface with 220 grit sandpaper to create a textured surface for the epoxy to adhere to. Rougher surfaces, such as wood slabs or MDF, do not require abrasion. In general, shiny surfaces should be abraded.
- Surfaces should be cleaned to remove any loose debris from sanding or residual contaminants such as grease, oil, wax or mold releases that will prevent bonding.
- Surfaces must be dry for good adhesion. Moisture on the surface will result in the formation of blush and prevent adequate bonding.
Porous surfaces may require a seal coat. Seal coats help prevent air and moisture from migrating out of substrate materials, which can cause bubbles in subsequent coatings or additional layers. If the seal coat cures shiny, it should be abraded and cleaned before recoating.
How do I prevent bubbles in my epoxy?
Entrapped air is usually caused by aggressive mixing of the resin or can be introduced when encapsulating objects. Porous objects, such as wood, and objects with curved surfaces, such as seashells, can trap air that can migrate into the resin once submerged. To minimize bubbles, use the following practices:
- Do not aggressively mix epoxy. Mix slowly until the epoxy is streak-free and clear.
- If including wood or other porous items, seal coat them before encapsulation. Any air present will be unable to escape.
- Objects with curved surfaces can be brushed with UVPoxy before adding them to the mold. This breaks the surface tension and can reduce bubbles.
- Pour slowly around encapsulated objects. Pouring too quickly can result in pockets of air trapped under objects which may migrate out during cure.
Monitor the resin for bubbles after pouring, checking periodically during the working time. If bubbles do appear in the epoxy, wait for them to come to the surface then use the following methods to release the air:
- Use a torch to heat and release bubbles. Hold the flame tip 1-2” off the surface and move the torch quickly in a sweeping motion to burst all visible bubbles. Do not allow the flame from the torch to touch the epoxy. A heat gun can also be used but care must be taken not to disturb the surface of the resin.
- Use a toothpick or other pointed tool to release the air bubble.
How do I install fasteners in epoxy projects?
We recommend using threaded inserts for attaching fasteners into epoxy. Threaded inserts have a recommended drill size, but for drilling into epoxy, we recommend using a drill that is 1/16th inch larger. The increased hole diameter will prevent damage to the epoxy. For drilling into wood, follow the manufacturer’s recommendations. If inserts cannot be used, you can drill and tap the epoxy to accommodate machine screws for light loading. Epoxy is comparable to softwood when it comes to screw retention.
What is blushing? How do I remove it?
Blushing is a chemical reaction between the hardener, carbon dioxide, and water present in the air. Blushing will appear as a white wax-like film on the resin surface, that will yellow over time. Blushing will interfere with adhesion of subsequent coatings and is difficult to remove. To prevent blushing, avoid working in humid environments or areas where you are burning fuels (propane/butane heaters, vehicle exhaust, wood stoves, etc.). Avoid condensation by working several degrees above the dew point throughout epoxy application and cure.
If blushing does occur, you can attempt to remove it using a scrubbing pad with soap and warm water. Amine blush is water soluble, so several repetitions of the cleaning process with water changes will be necessary. Do not use solvents or sandpaper to remove blush.
Health and Safety
What safety concerns are present when I am working with epoxy?
When working with epoxies, you should be aware of hazards that come from contact with the liquid resin and hardener. Common exposure routes are skin contact, eye contact, inhalation or ingestion. Clothing that protects the whole body from splashes must be worn when working with epoxies. Skin exposure can result in sensitization and irritation. Severe eye damage can result from eye exposure to hardeners. Personal protective equipment such as gloves and safety glasses must be worn to avoid the risk of skin and eye exposure. Epoxies should be used in a well-ventilated workspace. Wash hands with soap and water before eating or drinking. Consult the product’s Safety Data Sheet for complete health and safety information.
What safety precautions should I use when working with epoxy?
EcoPoxy resins and hardeners can be used in a well-ventilated indoor workspace without respiratory protection (excluding spray applications). Uncured epoxy resins are chemicals, and clothing that protects the whole body from splashes should be worn when using them. Personal protective equipment such as gloves and safety glasses must be worn to avoid the risk of skin and eye exposure. Wash hands with soap and water before eating or drinking.
Eye exposure can result in permanent damage. In the event of contact with eyes, irrigate with plenty of gently flowing lukewarm water for 15 minutes and seek immediate medical attention.
Refer to the appropriate Safety Data Sheet, available on www.ecopoxy.com, for a full list of safety hazards and precautions.
Are epoxies safe for children to use?
We do not recommend that young children use epoxy products. Many children will lack the awareness to avoid eye or skin exposure and will not have access to properly fitting PPE. However, epoxy resins and hardeners do not inherently pose any additional health risks to children in comparison to adults.
Are EcoPoxy products non-toxic?
Epoxy resins have potential hazards associated with their use. In their unreacted forms, epoxy resins are generally classified as non-toxic and hardeners are classified as low toxicity. To work with epoxy products safely, wear proper PPE (gloves, glasses) and work in a well-ventilated area. Avoid eye and skin exposure. Do not ingest. Once fully cured, the epoxy is non-toxic. When finishing cured epoxy, use of PPE is still recommended to avoid dust exposure or inhalation. Consult the product’s Safety Data Sheet for complete health and safety information.
How can I remove epoxy from skin and clothes?
When working with epoxy it is recommended that along with proper PPE (glasses, gloves, etc.) you wear long sleeves in order to avoid skin contact. Tie long hair back and choose to wear inexpensive clothes or a disposable Tyvek jacket. If you get resin on your clothes, change them immediately. Do not continue wearing soiled clothing.
If you get resin, hardener or mixed epoxy on your skin, remove it immediately. Do not use solvents such as acetone to remove epoxy from your skin. Use a solvent-free hand cleanser to remove resin or mixed epoxy from your skin. Hardener can be removed with soap and warm water. Cleanse until there is no trace of residue on your skin.
Resin, hardener, and mixed epoxy are not easily removed from clothing. Remove clothing while cleaning to avoid dermal exposure. Wear proper PPE while cleaning. Below are methods for removing resin and hardener from clothing.
Note: Some of the solvents and methods may damage or discolor fabrics.
- Resin only: Acetone or denatured alcohol
- Hardener only: Soap and warm water
- Mixed: Soap and warm water
Can I use FlowCast® for small pours?
Used in low volumes, FlowCast cures extremely slowly. Product cure times vary depending on the volume used. For smaller castings, such as serving trays or coasters, we recommend that you use FlowCast SPR.
Can I do multi-layer pours?
Yes, FlowCast is suitable for multi-layer pours. Additional layers can be poured without surface preparation when the previous layer is tacky to touch. If the previous layer is no longer tacky to touch, you will need to wait for the resin to reach sufficient hardness (approximately 72 hours), then scuff the surface with 220 grit sandpaper. Remove excess dust and debris with compressed air and wipe the surface clean with denatured or isopropyl alcohol before pouring the next layer.
Can I pour thicker than 38mm (1.5”)?
If you are planning to pour thicker than 38 mm (1.5”) and at a volume greater than 30 L, pouring in multiple layers is suggested to prevent overheating. Alternatively, you can actively cool a thicker pour with fans, but you must be prepared to constantly monitor the temperature to make sure that your project does not overheat. Note that results will vary depending on ambient temperature. When mixed in large quantities, this product can generate significant heat. Handle with care.
Do I need a seal coat? What product do you recommend?
We recommend seal coating any surfaces that will be submerged in FlowCast. Seal coats help prevent air and moisture from migrating out of submerged materials, which can cause bubbles. UVPoxy is the preferred system for seal coats as it is a faster curing resin made for applying in thin layers. Cured seal coats should be abraded and cleaned before proceeding with pours.
What products can I use to finish my FlowCast project?
For a high gloss top coat, EcoPoxy’s UVPoxy is an ideal choice. For matte to gloss finishes, use wood wax, hard wax oil, or urethanes. Any product that is intended for wood finishing is compatible with FlowCast.
Will my project yellow over time?
All epoxies yellow over time. To combat this, we formulated FlowCast with UV stabilizers. These additives absorb UV light and prevent damage to the resin. Eventually, the stabilizers will lose their effectiveness. Adding metallic or liquid pigments to FlowCast will help it resist yellowing better than if it is left transparent. Completed projects should not be kept outdoors.
I am an experienced FlowCast user. What do I need to keep in mind when using FlowCast SPR?
FlowCast SPR provides the same beautiful results as FlowCast with two key differences:
- At the start of mixing, FlowCast SPR will feel slightly thicker and will be more difficult to mix. However, once mixed, FlowCast SPR will feel like FlowCast.
- FlowCast SPR reacts faster than FlowCast and can reach higher temperatures while curing given the same casting size. This means you can create smaller volume or thinner profile projects that cure faster. However, this also means that FlowCast SPR is not suitable for larger pours.
Can I do multi-layer pours with FlowCast SPR?
Yes, FlowCast SPR is suitable for multi-layer pours. Additional layers should be poured when the previous layer has reached set to touch. To prepare the epoxy surface for the next pour, scuff the surface with 220 grit sandpaper. Remove excess dust and debris, then wipe clean with denatured or isopropyl alcohol. You can then pour the next layer.
Can I pour deeper than 25 mm (1”)?
If you are planning to pour deeper than 25 mm (1”) and at a volume greater than 3 L, pouring in multiple layers is suggested to prevent overheating. In large quantities, FlowCast SPR can generate significant heat, which can cause projects to yellow or form cracks. If multiple pours of FlowCast SPR is not an option, for projects that require pours greater than 25 mm (1”) in depth, it is recommended to use FlowCast.
Do I need a seal coat for FlowCast SPR? What product do you recommend?
We recommend seal coating any surfaces that will be submerged in FlowCast SPR. Seal coats help prevent air and moisture migrating out of submerged materials, which can cause bubbles. UVPoxy is the preferred system for seal coats as it is a faster curing resin made for applying in thin layers. FlowCast SPR can also be used but will not get to the tacky state as quickly. Cured seal coats should be abraded and cleaned before proceeding with pours.
Will my FlowCast SPR project yellow over time?
All epoxies yellow over time. To combat this, we formulated FlowCast SPR with UV stabilizers. These additives absorb UV light and prevent damage to the resin. Eventually, the stabilizers will lose their effectiveness. Adding metallic or liquid pigments to FlowCast SPR will help it resist yellowing better than if it is left transparent. Completed projects should not be kept outdoors.
What is the difference between UVPoxy and FlowCast®? What do I need to keep in mind when using UVPoxy?
UVPoxy is a coating resin, while FlowCast is formulated to be used for large castings. Like FlowCast, UVPoxy cures to a high gloss water clear finish. However, UVPoxy is a much more reactive formulation than FlowCast. The reactivity is optimized to allow it to cure quickly when applied as a thin coating. UVPoxy is not meant for small castings and does not have optimized air release.
What kind of projects can I use UVPoxy for?
UVPoxy can be used as a clear coating or be pigmented and used to create fluid art using techniques such as:
- Dirty Pour
- Beach Scenes
- Dutch Pour
Can I apply UVPoxy in multiple layers?
Yes, UVPoxy can be applied in multiple layers. Additional layers should be poured when the previous layer has reached set to touch. To prepare the epoxy surface for the next layer, scuff the surface with 220 grit sandpaper. Remove excess dust and debris, then wipe clean with denatured or isopropyl alcohol. You can then pour the next layer.
Can I apply a coating thicker than 3.2mm (1/8”)?
We do not recommend attempting to apply UVPoxy coatings greater than 3.2mm (1/8”). Thicker applications will cure too quickly to allow air bubbles to rise to the surface. To achieve a thicker coating, applying multiple layers of UVPoxy is recommended.
Do I need a seal coat for UVPoxy? What product do you recommend?
We recommend seal coating any surfaces that will be coated with UVPoxy. Once cured, seal coats help prevent air and moisture from migrating out of substrate materials, which can cause bubbles. UVPoxy is the preferred system for seal coats.
Will my UVPoxy project yellow over time?
All epoxies yellow over time. To combat this, we formulated UVPoxy with UV stabilizers. These additives absorb UV light and prevent damage to the resin. Eventually, the stabilizers will lose their effectiveness. Adding metallic or liquid pigments to UVPoxy will help it resist yellowing better than if it is left transparent. Completed projects should not be kept outdoors.
Can I use a Power Mixer to mix UVPoxy?
Using a power mixer is not advised. UVPoxy should be mixed by hand. Mix with a stir stick and stir deliberately, but do not whip the resin. Doing so introduces excess air into the mixed resin, which makes it difficult to achieve a bubble-free final project.
How do I get a perfectly flat UVPoxy coating on top of a wood surface?
In order to obtain a perfectly flat and level epoxy coating, the surface under the coating also must be flat and level. Natural features in wood surfaces, such as knots, cracks, and areas with larger pores, can absorb more resin than surrounding areas. This results in indentations and low spots. If your work surface has any of these features, 2-3 seal coats may be required to fully seal the surface. Apply the first seal coat, sand with 220 grit sandpaper, and wipe down. Examine the surface carefully to confirm that all voids have been filled and the surface is flat. If this surface is not smooth, seal coat and sand again, repeating as many times as required until the surface is perfectly flat and level. Then, continue to the flood coat.