RESINS
TWO-PART REACTIVE RESINS
These tips are for two-part epoxy resins such as Art Resin, EX-74, MasterCast 1-2-1, EnviroTex Lite along with other resins with a 1:1 mixing ratio.
Pēbēo makes Crystal Resin along with other resins, but the mixing ratio is 1 part resin to two parts hardener. This resin as well as the other thinner resins generally produce fewer bubbles than the thicker resins.
• Resin should be purchased when fresh. Compare the color of the two parts to determine freshness. The more transparent the hardener, the fresher the product. If the hardener has turned a dark amber, it should not be used. The older product will produce more bubbles that are more difficult to eliminate.
• Purchase only as much resin as can be used in a three month period. Resin comes in a wide variety of sizes ranging from small amounts that a jeweler uses to large quantities that a furniture maker uses.
• If using resins on smalls, such as jewelry, purchase the smaller quantities of resins. There are special jewelry resin formulas that are made with eco-friendly materials and safer to use for items that may be worn close to the skin or face.
• EX-74 is a two part resin by ETI that is specially formulated with a UV inhibitor to reduce yellowing and surface degradation from UV exposure. Note: EX-74 has a slightly different cure rate than the EnviroTex Lite made by the same company.
• Each brand of resin has a different viscosity, cure rate, and some specific properties that may work better for one application over another. Start small and experiment to see which works best for your use.
• Resins vary greatly in price. I prefer EX-74 sold by F. E. W. Products for surface coating for my use and price. EX-74 is very much like MasterCast 1-2-1, and it works well for me, too. However, if you like a thinner final coat, you may prefer Art Resin or Crystal Resin. The price is almost half for EX-74 if purchased in larger quantities than some of the other resins.
SET UP and ENVIRONMENT
• Wear lint free clothes when working with resin. Fleece, sweaters, and floppy sleeves will create lint that may cause extra work, time and extra layers of resin to cover.
• Check table to be certain it is level. Resin is self-leveling and starting with a level table will insure an even layer of resin. If table cannot be easily leveled, use popsicle sticks to level the painting on the table.
• Work on a piece of heavy plastic or a non-stick surface to prevent item from becoming permanently attached to the work surface. Laminating plastic does not melt or wrinkle as much as other thin sheets of plastics do when using the butane torch to pop bubbles. If there are drips onto the laminating plastic, the resin can be popped off easily and the plastic can be reused. Laminating plastic can be expensive unless sourced from overstock stores. I have found end rolls of laminating plastic at the Scrap Exchange in our area. For smalls, Teflon sheet liners that are used for baking work well. Some freezer papers also work well when using the slick side.
• Work in a well ventilated area and only work with a reasonably fresh product. A good exhaust fan will make working with resin easier. It has become common for manufacturers to claim on the MSDS that their resin is non-VOC and non-toxic. However, I urge you to disregard these claims since anyone can be highly sensitive to resin to the point of rash, swelling, difficulty breathing, or anaphylaxis.
• Always wear disposable gloves and a respirator when working with resins. Any resin that splatters onto clothing will be very difficult or impossible to completely remove so an apron or old disposable clothing is preferred.
• The most transparent and best results are in 70-72 degree temperatures with low humidity. Low temperature, high humidity or unequal mixing of the two parts may cause clouding of the resin. High temperatures may result in a cure that is too fast for some art techniques.
• Items to be coated should be clean and dry. If applying to a highly polished surface, a light sanding will assure a good bond. NOTE: I have never had a second layer of resin delaminate without sanding, but some manufacturers recommend sanding if first layer of resin was applied more than 24 hours prior. Be sure the surface is cleaned well prior to applying additional coats.
• If coating an acrylic pour with silicone in the paints, take extra care to clean the surface of all silicone before applying the resin. Some resin artists put a bit of silicone in their resin and the claim is that this helps the resin flow evenly over the surface without leaving divots where the silicone spots were in the paints. I have had about a 50% success rate with this method. I prefer polishing the acrylic pour after it has thoroughly dried with a soft dry T-shirt and then cleaning well with Windex and drying well. I have also used Dawn dishwashing liquid and other cleaners to clean well. Most importantly, the surface must be clean, dry and free of silicone.
• If an adhesive has been used to adhere materials to a board, be sure the adhesive has dried thoroughly. Otherwise, small bubbles will continue to rise to the surface through the wet resin. These bubbles are more difficult to remove than ordinary resin bubbles. If applying some papers to a substrate, they may turn translucent with the resin application if not sealed first. Golden or Liquitex mediums work well to seal the papers first.
• If working with panels that have a cradle such as Ampersand’s cradled panels, apply painter’s tape around the edges to protect the sides unless your art covers the sides of the cradle. Use tape that is wide enough to go under the panel about one half inch. A hard substrate is preferable to a flexible one such as canvas when using resin.
• If using stretched canvas, support the back of the canvas with poster board or other hard board so it does not sag with the weight of the resin.
• With large panels, use a heavy duty Lazy Susan to support the panel. This allows the panel to be turned to access it easily and to view the surface in a different light.
• If additional height is needed, use Painter’s Pyramids to raise the panel higher.
• If pouring resin on a thin, flat surface such as items that are less than 1/4” thick, put the item on a plastic sheet or a Teflon sheet liner. It is often not practical to use painter’s tape on the sides of items that are so thin. Applying painters tape to the back of flat pieces will make it easier to clean if any resin runs underneath.
• If my studio door has been open a lot during the day, an hour before a big pour, I often mix up an ounce of resin and spread on a piece of plastic so that any bugs, (Fruit flies love resin!) will be trapped before I begin a resin session.
• Some paintings may require the resin to cover the cradled sides. If that is the case, you will want to support your panels so the resin will run on the sides and as it starts to gel, you will need to smooth it out.
MIXING
• Mix only enough resin for a particular project at a time. With practice, it is possible to mix the correct amounts for a given size. Since the resin must be discarded if not used within the hour, it is best to have a few smaller pieces ready if too much resin has been mixed.
• There are charts online for determining the amount of resin that you will need to coat a painting based on the square inches.
• Use disposable plastic cups for mixing. Size of cup is dependent on amount of resin to be mixed. Save old plastic food containers for the larger quantities. They can be discarded without guilt! Clear plastic shot glasses for small amounts and the larger clear glasses for medium quantities allow you to see how much to pour into each container. Some party stores have pint, quart and half gallon plastic containers with straight sides that are used for deli foods. These work well for large pours. I like this particular measuring cup for large quantities. Different ratios are marked, and it is easy to clean for reuse. There are also silicone cups that can be reused easily.
• Wooden popsicle sticks or paint stirrers can be used to stir the resin. Some companies have a variety of scrapers and spreaders for resin application. Scrape the sides of the container often. At first, mixing will cause the resin to appear cloudy. Continue to stir for two or three minutes or until the mixture is clear. Bubbles will be present, but resin should be clear. Do not beat the resin, but scrape the sides of the container often to be sure all resin is mixed. Three minutes of mixing should be plenty of time for most quantities of resin. Resin gets hot as it cures so it can begin to cure if it is mixed too long. The bubbles are hard to remove in resin that is over mixed and especially if in depths over 1/4.”
• If using cups that do not have measurement markings, use a ruler and mark two containers at the same height in order to get an equal amount.
POURING AND FINISHING
• As soon as resin is thoroughly mixed, pour onto the surface of item to be coated. If enough resin has not been mixed and more resin has to be added, there may be clouding or a ridge where the two meet. If this should happen, use your hand in a rubber glove and attempt to mix the resin more completely on the surface. The resin may need to be warmed with a torch if it has already passed thirty minutes of curing time.
• Pour resin in the center of the panel. The amount should cover approximately 65% of the surface of the panel or board. Except for very porous surfaces, this will be enough resin to coat the item. Pour a smaller circle in the center for the subsequent pours.
• Using a rubber gloved hand or a spreading tool, pull the resin to the edge of the panel. Resin has a surface tension, and it will stop where it is pulled as long as too much resin has not been poured. Thicker resins will not run over the sides as easily as the thinner resins.
• A straight pin or a toothpick is handy to remove lint, foreign matter, or small bubbles.
• If working on a small project, blowing through a straw will remove bubbles. However, be careful that moisture does not accumulate in the straw and blown onto the surface. If working on a large surface, use a small butane torch to pop bubbles. This is my preferred torch since it is not too small and not too large. Holding the torch a few inches from the surface, move continuously over the entire area. If using a large quantity of resin, a good butane torch is a necessity. I went through four of the creme brûlée torches before I settled on a higher quality torch. I have not had to replace my torch in at least five years. If doing smalls such as jewelry, the creme brûlée torches should work fine. Using a butane torch may seem like the resin will heat up too much, but a heat gun often heats the resin even more before the bubbles are popped. It is best not to overheat resin!
• Check the item every fifteen minutes for the first hour for lint, foreign matter and bubbles. Flaws can usually be corrected within this time frame.
CURING AND MAINTENANCE
• Cover item to prevent dust settling on it. Plastic bins work better than cardboard boxes. (The resin can be peeled from the plastic should it stick to the rim of the upside down bin.) Cardboard boxes often have dust or small particles that can fall onto the panel.
• If micro particles have accumulated on the resin within the first hour, and removing dozens or hundreds of them is too tedious, it is possible to warm the resin and rub it as one would do when first applying it. This often traps the micro particles, and the surface will cure without their showing. The resin will still need to have bubbles removed with a torch.
• Allow to cure 24 hours before touching if no second coat is required. A second coat can be applied in about 12 hours. Do not place anything on it for at least 48 hours. Allow to cure 72 hours before packaging to ship. Some resins do not reach their full hardness for 30 days.
• To obtain a satin finish, use 0000 steel wool and rub in a circular motion. Allow at least 36 hours before rubbing the coating or it may scratch or mar rather than resulting in a satin finish.
• EnviroTex Lite makes a spray sealer in a high gloss. Once sprayed it is closer to a satin finish than a high gloss. Spray within 24 hours after the resin coating has been poured in order to get maximum adhesion. If waiting too long, it may scratch off easily and not bond to the poured coating. This is an acrylic spray sealer and was originally made to seal delicate items before coating in resin. However, it can be used to tone down a high gloss resin finish.
• Liquitex Soluvar Spray Varnish is my preferred finish if spraying on top of cured resin to get a satin finish. I have had no problem with any chemical reaction with resin and this varnish. I have used other spray varnishes that would react with the cured resin. It is a good product to use if a painting is going to be hung where light is bouncing around and interfering with a high resin gloss finish.
• Clean finished pieces with a soft cotton cloth and glass cleaner or eyeglass cleaner. Avoid paper towels.
• If a piece is thin and there is overrun, leather scissors work well to trim off the excess resin. This should be done about eight to twelve hours after pouring or the overrun should be heated with a torch and then trimmed off. Be very careful not to get fingerprints on the resin that has not fully cured.
• If a piece has been stored next to an object that has left a mark or scuff, a heat gun continually passing over the area may make the resin pop back. Be careful not to overheat or it may cause another mark that will result in having to re-coat the piece.
CLEAN-UP
• Alcohol (71-91%) works well for cleaning tools.
• Mixing containers can be cleaned with alcohol in order to reuse. If resin is allowed to cure in some containers, sometimes it is possible to remove the resin in one or two pieces and then the container can be reused easily.
• Do not use lacquer thinner for clean-up or with resin. Lacquer thinner will cause resin to ‘weep’ continuously for sometimes months and will prevent the resin from curing. Lighter fluid may be used to remove adhesives from cured resin.
If you have questions about two part resins, feel free to contact me or read my blog.
Web site: JeanneRhea.com
© Jeanne Rhea 2019 All rights reserved.
This may be copied and shared as long as it is copied in its entirety and credit is given.
NOTE: Please print out all the way to the statement above. I am serious about copying this in its entirety to that point. You may use this in teaching, sharing or your own use as long as printed out with credit given above.
This was primarily written for coating paintings and not for mixing paints, powders, and pigments into the resin to paint. I will cover that in a different post.
I may add more info to this post as I think of important points that I may have missed. I hope this helps in your resin journey!
