Top 10 Reasons Why Your Resin Isn’t Curing

Top 10 Reasons Why Your Resin Isn’t Curing – Have you ever been playing the waiting game after you created what you thought was your resin masterpiece, only to find out the next day it just didn’t cure? Well if this has happened to you, then we are here to tell you, that you aren’t alone. Uncured resin has happened to the best of us at some point. So in this blog, we are going to share the top 10 reasons why your epoxy resin didn’t cure as expected.


1. Incorrect Measuring:
Resin is a meticulous mix of Part A – Resin and Part B – Hardener, that demands accuracy when measuring. Whilst many epoxy systems have a good tolerance, a miscalculation in the resin-to-hardener ratio can quickly throw the entire curing process off balance. It is very important to follow the manufacturers’ instructions of the resin you are using and whether they recommend mixing by weight or volume. If your resin says to measure by weight, it is important to have a set of scales that are correctly calibrated before use.

2. Incorrect Mixing: Invest in reliable measuring tools and double-check those ratios for a foolproof mix. Ensure you have a good mixing technique that incorporates scraping the sides and bottom of the mixing vessel. If you are unsure how to mix correctly, see our YouTube Video.

3. Temperature: Resin can be a temperature-sensitive medium. Whether it’s too hot or too cold, temperature can significantly impact the curing process. Find the sweet spot, and your resin will reward you with a perfect cure. For most resins, 20-25 degrees Celsius is ideal. Check the manufacturers’ instructions to confirm. If the temperature is below this, and your resin is still sticky, it can be possible that it just needs more time to cure. If this is the case, allow the resin some more time to cure, resin always requires patience.

4. Old Resin: In many cases, ‘old’ resin may not work for your desired outcomes. Whilst we have specifically tested, all of our systems past 5 years old and still been able to work successfully with them, this may not be the case for every brand of resin. With age comes contamination from moisture or other debris, depending on how the resin is stored. As resin ages, it can also darken in colour. If you have resin past its expiration, we recommend testing on a small sample scale first, before completing a big project that may result in an uncured mess or otherwise.

5. Moisture: Moisture is the arch-nemesis of resin. Even a hint of humidity in the air can determine the end result of curing. Ensure your workspace is dry, and you’ve sealed your materials well to keep moisture at bay.

6. Mixing Wrong Materials: If you have left over parts of different resin systems or resin brands, it may seem like a good idea to mix the systems together to use up the leftovers. We can tell you, this is NOT a good idea. Whilst all epoxy resins may seem similar and offer similar properties, the chemical compositions are all vastly different. This means that mixing a Part A from one brand and some Part B from another brand, can very much lead to uncured or sticky resin. If you have excess resin leftover, it would be recommended to contact your resin manufacturer direct to request the additional part, so you can measure and mix correctly.

7. Contamination:  Again, whilst resins have an excellent tolerance in many cases, contamination can be a big issue when it comes to curing .Resin loves a clean slate. It is important that your mixing containers and tools are free from any residue, alcohol or debris of previous projects or contaminants that might disrupt the curing process.

8. Pigment Overload: While pigments and dyes can add a brilliant burst of colour to your resin creation, going overboard can quickly hinder the curing process. Ideally use between 2-5% colour to resin for the best curing results. Anything past 10% can lead to soft, chewy or sticky resin. An easy rule of thumb, start with less and add more if necessary, as you can always add but you can’t take pigment out.

9. Resin Thickness: Similarly to temperature playing a big part in how resin cures, the depth in which you pour your resin can also lead to uncured resin or stickiness. Whilst it may seem smart to pour a certain depth, it is important to check that it is within the resin systems capabilities. Some systems have a depth minimum and maximum. If you pour below the minimum, it is likely that the resin will not cure correctly. To avoid this, ensure you are pouring above the minimum layer depth.

10. UV Resin Curing: When it comes to UV Resins, many find that they are left with sticky pieces. Generally UV Resins only require a few minutes under the Ultra-Violet light to fully cure, however if the resin has colour added, it is poured into a mould or it is thicker than 2mm, it can take much longer to cure. With any UV Resin system, we recommend using the UV light based on the manufacturers instructions, then allow the resin to cure in direct sunlight for a few additional minutes. The natural UV light is much stronger and leads to a better cure and finish with the sing-pack resin systems.

At the end of it all, it is important to remember that each resin brand and resin system has its own quirks and preferences. Reading the provided instructions and following the guidelines provided, will ensure a smoother journey from liquid to solid. Patience, precision, practise and a dash of creativity will have you creating resin masterpieces that cure flawlessly every time.

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U RESIN

We are a 3rd generation of family-owned business specialising in epoxy resin manufacturing and supplies. We are located in Perth, Western Australia, where we manufacture and distribute all of our resin products. We focus on three characteristics: Dependability, Customer Service and Uniqueness.
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