Every artist enjoys the feel of creating a bubble free resin craft that turns out flawless and reflects the vision of our thoughts. But finding bubbles in your resin during resin curing completely ruins the look of your project. It is a very common issue that when you mix resin with the hardener, it develops some bubbles and appears cloudy.
What Causes Bubbles In Resin?
Bubbles are one of the biggest issues when you hear resin craft. There are many reasons why these bubbles pop up. Here are the most common causes of these bubbles developing in your resin:
Reactions
Sometimes these bubbles popped due to the reaction between resin, photo paper, and the adhesive used to mount the paper on the substrate. This reaction results in the formation of micro-sized bubbles in your resin.
Off-Gassing
Organic materials like wood, porous substances, leaves, and some low-quality paper emit the containing air or moisture depending on the climate and temperature or the environment. These materials will continue to release air even after being covered with resin. This process is called off-gassing, and it results in the formation of bubbles in the resin. In some cases, these bubbles may even develop after several hours you have poured and torched the resin.
Cold Temperatures
The ideal temperature for your workspace and your resin crafting is 75-80 F or 24-30 C, which is slightly warmer than your room temperature. Epoxy resin is crystal clear, beautiful, and has a consistency similar to honey. But if the resin is cold, its consistency can be thick and clumpy which may make it difficult to work with. It will also appear cloudy or milky due to thousands of micro-bubbles. You won’t be able to eliminate these bubbles even by using a torch.
How To Remove Bubbles From Resin?
The most frustrating thing for an artist is working tirelessly on your craft and getting results that are less than satisfying. Finding bubbles in your resin craft ruins the look of your project. It is very important to get those bubbles out of resin before it cures. Here are some fast and effective ways to remove those bubbles and make your project perfect again.
1. Monitoring the temperature of resin, surface, and surroundings
Resins need an ideal room temperature of 70-75 Fahrenheit for curing. Of course, it isn’t convenient for everyone to have heaters running all the time to have the temperature maintained at the perfect rating for resin; so instead, opt for heating a small part of your house like a closet or bathroom perhaps. A portable heater can be more than enough for this purpose. A “Hot Box” is another good suggestion for smaller resin craft; especially if you are looking for casting resin in molds or bezels.
2. Selecting the proper resin
It is very important to select the right kind of resin for the kind of work you are doing. For instance, using a thinner resin is ideal if you want to cast it in molds or bezels as it has low viscosity, hence, it has lower chances of developing bubbles. Nonetheless, if there are still some bubbles present in your mixture, there’s no need to worry. As your resin and hardener mixture is thinner, the bubbles will escape easily. Thicker resin tends to develop bubbles as it is generally for doming projects due to the casting having high viscosity.
3. Mixing resin and hardener carefully
Exercise caution when mixing resin with the hardener as you aren’t just beating eggs. Mix it attentively and with care when you are mixing at the bottom or along the sides of the container. Often when dealing with a large volume of resins, developing bubbles is rather unavoidable. Some of the bubbles might come up to the surface of the resin while you pour or cast it.
4. Using a torch or a hot air gun
This is the fastest and the most effective method, so make sure to start with this tip. You have to be really careful with this method because the flame is near the resin. Make sure to do it quickly and don’t keep the flame on the surface of the resin for too long. Only 1-3 seconds of heat exposure is required at a time. I recommend you to repeat it 1-3 times, and also wait for several minutes in between to allow the resin to cool. If you overheat the resin using the flame too much, it may not allow your resin to harden completely for months. Usually, when you overheat or over-use the flame, the cured product has a grainy, sticky texture on the surface instead of a smooth, slick surface. If you are using resin molds, there's also a chance that the overheated resin melts the mold and causes the mold to rip.
It's also important to choose a proper torch. We recommend Sondiko Butane Torch S400, which is easy to adjust the flame, easy to fill, and fits nicely in most hands. It also has a dial that you can simply switch to keep it stay on for longer use after lighting it so you don’t have to keep your thumb on it. A must have to remove bubbles from resin.
5. Let bubbles escape naturally
When the resin and hardener mixture is thinner, it usually has a thinner viscosity. They are less likely to develop bubbles but if some bubbles develop on the resin surface, give some time to escape naturally. The reason why they escape naturally is that the resin and hardener mixture is thinner, and the bubbles tend to release easier from the surface of the resin. But, it is only for thinner resin mixtures, not for thicker resins. Thicker resins are generally used for doming projects, sculpture designing, and furniture. They hold bubbles, especially with thick casting. Doing resins are better suited for thin layers of pours.
6. Manually target stubborn bubbles
Manually, you can get rid of bubbles using a toothpick or a pin. This method is usually used for a smaller art pieces. Blowing on bubbles can cause them to pop on the surface. This process is slow and only works on small pieces like jewelry, rings, earrings, molds, or small river boards. Everyone has a hairdryer in their bathroom. Light heat from the hairdryer helps to remove air bubbles, but it is not intense like a hot air gun to fight against bubbles effectively. Dust a mica powder or liquid resin dye to decrease the surface tension of a mold. A small amount of colored baby powder may also work to stop bubbles from popping on the surface of the resin.
7. Pouring the resin the right way
Start by slowly pouring in the resin right in the middle of the cast while you hold the spout a few (two to four) inches away from the surface. This ensures an even distribution of the resin. If the mold you are using has an irregular shape, move the pouring cup evenly over the mold in a smooth circular motion. Be sure to avoid pouring resin over itself and keep taking different directions as you keep pouring the resin. If you make clockwise or anti-clockwise directions as you pour, this will prevent the formation of air bubbles. Nonetheless, once you have poured a layer, use a heat gun to remove the bubbles. Once done, repeat the entire process and pour one layer on top of the other to prevent the formation of bubbles. Once done, let it rest to dry which may take anywhere from 2-3 hours.
8. Using a pressure pot
Pressure potting is one of the best ways of removing bubbles from resin in case of large castings or when using clear resin like polyurethanes. You use a pot and place your mold/casting inside of it while pressure is created to reduce the size of the trapped bubbles. To ensure that the resin turns out bubble-free, the pressure needs to remain on the casting for the entire duration of the process.
9. Heating the resin in water
Cold resin equals a lot of trapped bubbles, so that’s something we don’t want. Instead, if your resin is significantly heated, it will have lower bubbles in it. of course, you can't directly heat the resin; instead, placing the resin in hot water will do the trick for you. You can either have the basket of resin placed in a bigger basket or tub filled with hot water or if you are unable to make arrangements for that, you can put the resin in a plastic bag and have it placed in the water. By having your resin heated in warm water and pouring it in thin layers, you can eliminate over 90% of the air bubbles trapped. A 20-minute warm water bath will do wonders for you.
10. Use powder to eliminate surface tension
Especially when pouring resin into the intricate molds, if you dust the surface with a little amount of baby powder, you can eliminate surface tension that will prevent new air bubbles from forming while molding the resin. Additionally, de-molding a few times can also eliminate the bubbles in molds with curves and depth. And before you fill the mold completely with resin, having resin poured around all the sides of the mold will prevent any air bubbles from forming in the sides and getting to the middle.
11. Sand-out and repour
In case your piece has already dried and still has a few bubbles that are either on the surface or just below it, you can use sandpaper and trim down the surface. This is particularly possible in the case of flat pieces. It can also be used for pieces that, although are not flat, can still be trimmed with sandpaper. Once done, clean the surface neatly and repour a thin layer of warm resin.
12. Mix from the bottom up
Whether mixing manually or with an electric mixer (using a drill) or a paddle, if you mix slowly and from the bottom towards the surface, it will naturally push all the bubbles towards the surface. This includes micro as well as big bubbles that often get trapped in case you are using something deep (like a bucket) to mix the resin.
13. New hack found in 2023
There's a game changer to remove all the bubbles and keep the resin absolutely clear. This resin bubble remover machine can suck out pretty much 99% of the bubbles in a short amount of time. Definitely well worth it to get one of these as removing bubbles in pouring resin is a huge deal in getting a really good pour. Use it once and you won't go back.
What Not To Stress Over?
Although it is very frustrating for an artist when they try to create a bubble-free craft and it ends up with some micro-sized bubbles. It is a very common thing when it comes to resin crafting and you don’t need to stress over or worry about it.
Now there are many ways to get rid of those micro-sized bubbles that make your project look cloudy, sticky, or filled with bubbles. There are also many manual methods to remove bubbles from the surface of your resin. Like, as you were using a toothpick or a pin, hairdryer, torch, or a hot air gun lighter. A minor size bubble is normal and won’t take away your peace because it won’t be noticeable normally. You need to understand that there are a lot of variables to play. It could be humidity, room temperature, or the brand of resin.
You usually don’t have to worry about doing smaller undertakings and using a bezel or mold for casting. In bezels, bubbles usually get sometimes stuck in the corners. Blowing the bubbles on the surface and using flame don’t help in popping corner bubbles. You need to move them to the center of the mold physically. Then you can try to pop the bubbles with a toothpick or a pin. Toothpicks are very user-friendly. You can easily swirl the bubble onto the toothpick and quickly wiping it off on a paper towel.
Resin is a type of epoxy glue that usually develops bubbles when they are poured and left to dry. But it is extremely important to pop those bubbles before letting the mixture dry completely. Getting bubbles out of the resin is an easy and safe process.
How to Get Bubbles Out of Cured Resin?
In case your resin has cured and there are still bubbles trapped inside, no need to fret as we still have you covered. Although there is no direct method of taking bubbles out of cured resin, you can still eliminate them by… eliminating them.
- Start by locating where you have bubbles trapped in your resin. If you have tried the methods mentioned previously to get rid of bubbles from resin in its uncured form, it is most likely the few that still remain are just below the surface.
- Use sandpaper and sand down the surface until you have eliminated the layer with bubbles trapped in it.
- Once you have done that, clean the surface thoroughly and eliminate the residue with a damp cloth. Be sure that there is no residue left before you put in a fresh coat of resin as it will again take you back to square one.
- Finally, put a fresh, warm, and thin coat of epoxy resin to make up for the lost surface area.
Be sure to have the resin that you are going to pour prepared according to the instructions previously discussed to ensure there are no bubbles that remain. Once it cures, your piece will look perfect with no air bubbles in it whatsoever!
Working with resin can be very tricky. You have to be very careful to avoid unnecessary mess and to do it right. It is a type of epoxy glue that is used to protect art, seal jewelry, and fill molds in furniture and sculptures. Some epoxy resin brands are better and easy to handle but, many brands need to be poured in thin layers to avoid fewer ugly bubbles. Follow the instructions and tips given above to get a flawless piece of art without any bubbles. It is a long list of rules to follow but trust me, the results would be worth it.
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7 comments
Does the ultrasonic method work on UV resin, if not what is the best method?
Would using baby powder on the mould effect the overall finish when the resin had cured? I have intricate tarot card moulds and there is many small bubbles around the imprinted images what could you recommend for this?