HELPFUL INFORMATION & TIPS WHEN USING RESIN
There are a large variety of different epoxy resins on the market for use in many different applications. Each resin has its unique features, pros & cons depending on what it's being used for. Some people like to use a variety of different resins for different purposes, and some prefer working with medium (thicker) or lower (thinner) viscosities depending on desired effects. For example there are resins designed for top-coating and wall art, some designed for casting in moulds, some with higher heat tolerance for countertops, some designed for flooring, and many more.
Two part epoxy resins consist of a base (bottle of resin) and a curing agent (bottle of hardener). The two components are mixed in a certain ratio. A chemical reaction occurs between the two parts generating heat (exothermic reaction) and hardening the mixture into an inert, hard plastic. Epoxy coatings are used because of their outstanding chemical resistance, durability, low porosity and strong bond strength.
At ArtWorks Resin Canada, we have over 6 types of iCoat Epoxy Resins, all formulated for different types of projects. See this blog post link to see what each of the iCoat epoxy resin types are suited for, along with their different characteristics.
If you know what projects you are planning to create, and would like to see which of our variety of resins may work, here is a blog post that covers which iCoat resins can work on which type of creations.
ALL resins will yellow ever so slightly over a period of time, however, iCoat Epoxies are formulated with the most recent UV anti yellowing technology available. It is not possible to determine how long it will take any cured resin brand to start becoming discoloured, as there are so many variables, such as additives by the user, overheating before or during work time or during cure time, and where the art is being displayed. Resin art, much like most original art, should not be displayed in direct sunlight.
The general rule of thumb for adding pigments/colourants to resin, is a ratio of less then 5-10% colourant to resin. If more is added it can affect the curing process of the resin negatively. Resin pigment pastes and powders, acrylic paints, acrylic inks, pigment & mica powders can all be added to colour your resin (but ratio needs to be less then 5 to 10%). Glitter does not colour the resin, so it doesn't follow the same ratio (however be aware that adding it can also reduce work time). Alcohol can cause issues with epoxy curing process, so when using alcohol inks, use in small amounts. Here is a blog post with more details on using colourants with epoxy resins.
This additional colourant related blog post discusses the difference between micas and pigments.
Prepare your work area:
Resin can be incredibly messy & sticky. For easier clean up afterwards, cover & protect your work area. Heavy guage plastic can be reused, as resin once dried will peel off the plastic. Parchment paper (or the shiny side of freezer paper or silicone matt) can also be used under projects on work surface for easy clean up.
Some people like to mist the air in their work area with water ahead of time, to bring down any dust in the air prior to starting with resin.
It's best to have all your supplies ready & near you before mixing the two parts together, so you don't waste work time (pot life) looking for things you need to use.
Have tweezers handy in case you need to pick out hair, dust or bugs (they seem attracted to resin).
Keep a roll of paper towels and rubbing alcohol handy as well for quick wipe ups as needed.
Also keep alcohol wipes (Clorox for example) handy for wiping resin off unwanted surfaces prior to it curing.
Mixing containers & sticks:
Always use clean mixing containers & stir sticks (so nothing contaminates resin).
Silicone containers & mixing sticks are often preferred since they can be reused once wiped clean.
Many people use wooden popsicle sticks or paint stir sticks, however be aware it's possible wood may release air into resin during mixing, and cause additional bubbles to mix. Some people prefer using silicone or plastic to prevent chance of added air bubbles.
Secure hair & loose clothing out of the way so it doesn't land in your work. Check clothing doesn't have hair or fuzz that can fall into resin. Have your box of nitrile gloves ready and other PPE (see resin safety tab for more detailed info on this).
Temperature of resin & room:
Temperature is extremely important with epoxy resins. Apply resin in correct room temperature 21C (70F) to 25.5C (78F), and temperature should remain consistent through curing process for a nice cure. Generally all epoxies become too thick and cure too slowly to be applied at temperatures below 50 or 60 degrees F.
It's very important that epoxy is at proper temperature (approx 23-25C / 72-78F) before mixing. Higher heat will expedite curing, yellowing and will make it more brittle. Be aware that since heat accelerates curing, warming your resin can reduce working time by about 10 minutes.
If the epoxy is too cold, the molecules are too small to make a complete chemical reaction to make it an inert final product, which can leave nasty BPA and corrosive chemicals not bonded (which is a potential for poisoning). Follow each manufacturers instructions to a T. ALL epoxy resins are chemicals, and all the controlled variables must be adhered to. Chemicals are sensitive.
You'll know your resin is too cold when it's thick, hard to work with, and cloudy looking due to 1000's of teeny-tiny micro-bubbles which are harder to torch out. Cold resin will also take far longer to cure.
If resin is too cold, you can set the Part A-Resin bottle in warm water (upright in a bucket, or tub), until it's room temperature (before mixing two parts together). Ensure you completely & thoroughly dry off the exterior of the bottle from any water drops (water drops in resin will ruin the chemical process and cause curing issues).
Epoxy resins curing properly can often be affected by ambient temperature being off, as well as humidity levels. After most of the epoxies have cured, it can handle temperatures below zero degrees F.
Tip: Use a digital infrared thermometer to take the guesswork out of working with resin. You can double check the temperature of your room, & more importantly the resin, which will save a lot of guesswork. Ensure all tools are at room temperature. Cold tools can shock your resin. Many resins need to be at least room temperature, however some resins require higher starting temperature (such as the iCoat CE4100HV casting resin). There are separate blog posts for each type of resin we carry with more details.
This blog post has more details about temperatures and working with epoxy resins.
Work Time/Pot Life:
After the two epoxy parts (resin mixed with hardener) are combined, there is a working time (pot life), during which the epoxy can be applied or used. Generally the pot life will be anywhere from minutes to one hour or longer depending on the product specs. At the end of the pot life, the mixture becomes very warm (or even dangerously hot), and when past it's pot life, it quickly begins to harden & yellow from overheating that occurs while still in cup.
iCoat epoxy resins each have varying work times. The different work times (pot life) for each resin type, is available in the blog about resins (Scroll down past general info). In theory, a temperature change of 18 degrees F, will double or half the pot life and cure time of an epoxy. Higher temperatures will lower the viscosity (thin) the epoxy, but also reduce the working time a person has to apply the epoxy. Spreading out the mixed epoxy instead of leaving it concentrated in a bucket or container will help get the most of the potlife (work time).
Torching/heating and removing bubbles:
For top-coating projects, after spreading epoxy on surface, if there are bubbles, pass a heat source (butane or propane torch) carefully over project using short quick passes. Ensure the flame doesn't touch the resin. Product will self-level. Be careful not to over torch your resin. Keep the heat source moving, because if you leave it in one spot too long, you may over-heat the resin, which can cause fish eyes, or film or other curing issues. Heat guns are not really suitable for getting rid of bubbles, since they do not degas resin. The flame from a torch sucks the oxygen (degases bubbles) from the resin, holding flame about 20 cm above resin. A heat gun can boil the resin (while it will release bubbles, remember resin heats itself to cure, & the heat gun can cook the surface), which weakens curing. Heat guns are often used to achieve certain effects, (artists are known to push the limits of numerous art supplies), & it can work, but know your heat limits or you can easily singe the resin. There are numerous other tools to get effects.
For casting resin projects, ideally you want to reduce bubbles as much as possible before pouring into moulds. There are a variety of different ways to handle castings resins. And often each brand has very different recommendations, so it's important to go with your brands suggestions.
Here is a blog post about dealing with bubbles.
Heating/speed curing in any resin: Heat will expedite curing (but not necessarily in a good way), unnecessary yellowing can occur and brittleness are often results of speed curing.
Speed/fast curing (using a heat lamp, space heater, etc), will make epoxy more brittle and cause pre-mature yellowing. It's best to just keep your room at a consistent temperature that is between 72 and 78 degrees farenheit for it to work as intended. Even use caution when using a heat to get rid of bubbles. Suggestion is quick, short passes only as the yellowing can start happening while it's still wet if too much heat is applied with any resin.
After curing, some types of epoxies will remain pliable, & begin to soften at about 140 degrees F, but will reharden when the temperature is reduced. For common epoxies this temperature is approximate upper end of their working temperature range. Special high temperature epoxies do exist (see blog about our resins for more information on various heat tolerances of iCoat epoxies). Resins typically continue to harden after initial cure for up to a month.
Protect project while curing:
When possible, close door to work area or tent/cover (with breathable cover) your finished work during cure phase to prevent dust, hair, bugs, etc from landing on curing project. Try to let project sit undisturbed during curing phase, so as not to stir up dust that could land on your piece.
Remember, overheating, overworking, dust, or not using enough resin can potentially cause divots or other undesirable finish in the cure of any epoxy.
iCoat epoxy resins each have different cure times, each of the those can be found in this blog about the resins. As with all resins, other factors come in to play as well depending on temperature, environment & products mixed in resin. Resins continue to harden for up to a 3 weeks after initial cure. For maximum heat resistance performance to be reached, allow 3 weeks.
If you are top coating your acrylic artwork with any epoxy resin, it is important to allow your acrylic art layer to cure completely before coating with resin. Many acrylic art pieces with only a thin coat can take up to a full week to cure, many other pieces with thicker or textured paint layers, or medium or heavy body texture of acrylics, can take over 2 - 3 weeks to cure all the way through. Dry to the touch, does not necessarily mean it's cured all the way through. If any resin is applied before acrylics are completely cured all the way through, the moisture from the uncured acrylic will effect the curing of the resin negatively, and a nice topcoat will not be achievable. The same applies to anything being used prior to resin topcoat, everything must be fully dried and have zero moisture content.
General epoxies harden in minutes or hours (depending on usage it's designed for), but complete cure (hardening) will generally take several days. Most epoxies will be suitably hard within a day or so, but may require more time to harden before the coating can be sanded (if needed). Higher humidity can cause some resins to cure faster, colder temps can cause slower cure. If it's too cold, it can cause dimples in the cured piece.
A faster curing resin (curing in 12-24 hours), the larger the batch mixed, the work time will be reduced accordingly (due to exothermic reaction). If making a larger batch it's best to move very quickly, or break it down into smaller batches (or a much wider container), or the resin can begin to get very hot in mixing container & start getting hard in cup/mixing container. If any resin overheats during active pot life (work time), this premature heat process could also potentially cause resin to prematurely yellow.
Moulds/casting, pouring depth/thickness:
It's not recommended to do any more then a 1/4" thick pour maximum, in one session with any top-coating type resins. The top-coating resins, can not go as deep a pour as a casting resin. If using top-coating resin in coaster moulds or other silicone moulds, better results could be achieved by pouring about 1/8" thick, then pop bubbles, then add a bit more (up to max of 1/4" deep), if desired & pop bubbles. You can add more layers after about 4-8 hours (resin type and temperature dependent), if keeping it under the 1/8" to 1/4" depth per pour. This is where an infrared thermometer will be helpful to know when it's okay to add next layer to prevent overheating.
If you are pouring in moulds that require deeper pours, you need a casting resin. We have 4 different types of casting resins, suited for different types of projects. Casting resin options have various different pour minimum and maximum depth recommendations depending on which epoxy it is.
If you pour any type of epoxy resin too deep, you risk overheating your resin, and undesirable results in your projects.
See blog post about our different resins, (scroll down past general info) which also mentions minimum/maximum pour depths for each epoxy.
Top-Coat or Recoat:
The best time to recoat or top-coat a top-coating epoxy for many (not all) epoxies is within about 48 hours after the initial coat. Because some epoxies take days to reach full cure, a second coat applied shortly after the first coat will partially fuse to the first coat rather than forming a simple mechanical bond. If done within a few days, it will not necessary to sand between coats unless something on the finish requires it. If sanding is necessary wait 24 hours or more (depending on which resin was used), for ease of sanding.
Fisheyes are typically never due to a resin. These are areas on a painted surface where the coating literally pulls away from the substrate, leaving a coatingless void or fisheye. More often fisheyes are caused by surface contaminants such as a bit of silicone, wax or oil (can be body oils from hands too). Or the contaminate could often be the type of spray/or medium previously applied, and sometimes it can be the substrate material used reacting with a resin. Surface tension plays a big part in fisheyeing. Applying a thick coat of epoxy over a contaminated fisheye surface will bury the fisheye, but without sanding and cleaning, expect the coating might peel away in the future.
As a rule of thumb, always suspect some sort of surface contamination or the type of material underneath, as the primary cause of fisheyeing. Pinholes are similar, but caused by expanding air bubbles under the still soft epoxy. Clean your surface well to avoid the contaminates. A successful application is all in the preparation. There are a variety of different mediums to apply this product on, so it's recommended to do a test piece first before applying your new resin on to your masterpiece.
Shelf Life/Storage: Store product in a dark but well ventilated area that is above 10C.
iCoat Epoxy Resins have a shelf life of 12 months unopened, and 6 months once opened (ensuring lids have been replaced tightly). The reason is due to oxidization. When the hardener in any resin is exposed to oxygen, it has a yellowing effect. This does not mean it won't cure. Even once past shelf life, the product still works, and will still cure. But older product may produce more bubbles that are more difficult to eliminate. You may want to just use it up any older epoxy, only with darker colours or tinted over wood. Ideally, try to plan to purchase only as much resin as can be used in a 3 month period.
So if you tend to make smaller items, like jewellry, purchase the smaller kit sizes.
Yellowing in the bottle: Yellowing in the bottle occurs in most if not all resins, it's from oxidization. It's very exaggerated & much more noticeable in the larger sized containers. Once mixed, it will be clear (if it's within the year shelf life). Some people (and even some resin companies) will add a purple die to help trick the eye into not seeing the yellow. This blog post about yellowing in bottle has more information.
If your resin arrives frozen, it will need to thaw naturally and acclimate to at least 75 derees F before using. This may take a few days. Cold or under-mixed epoxy can create sticky or wet areas on your surface. Cold temperatures will also trap more tiny air bubbles during the mixing which are much more difficult to remove even with torch/heat gun. Once resins are thawed naturally, if they still need a bit of warming, follow directions above for warming resin. Pay careful attention not to warm too much. This blog post about frozen resin has more details.
Some of the helpful blog posts from ArtWorks Resin Canada are already posted above in blue text, however under the blog tab, there are many more links to a large variety of blog posts you might find helpful in your resin journey.
Please review the helpful information & tips (as well as the safety information provided in next tab), prior to beginning working with resin.