You buy resin, mix the two parts together, then use it for your project. That’s the end of it, right? 🤞 It is, unless you find yourself asking ‘Why is my resin sticky?’
There are eight reasons this happens. And you might be able to fix your tacky resin too.
Reason 1: Resin and hardener measured inaccurately.
Getting accurate measurements on your resin and hardener aren’t optional. They’re essential. The best way you can do that is by using mixing cups with graduated lines to measure as precisely as possible. Or, your resin kit instructions might say you can use a digital scale to measure your resin and hardener by weight.
Reason 2: Undermixing resin and hardener.
Mixed feelings are the only ones you should ever have about your resin. You need to scrape the sides of your cup and stirring stick several times. Make sure you bring that unmixed resin to the center of the cup and continue blending.
💡 Pro tip: Ever have cured resin but with a few sticky spots? You likely mixed the center well, but not the resin on the side of the cup. When you scraped out the cup to use that last bit of undermixed resin, it cured sticky.
If you’re a resin newbie, you’ll love this video on how to mix epoxy resin:
Reason 3: The resin and hardener didn’t get warm enough.
Your resin working area needs to be in the low 70s F (low 20s C) during the entire mixing AND curing time of the resin.
💡 Pro tip: Warm up your resin and hardener bottles in a hot water bath before use. This jumpstarts the resin-curing reaction to the ideal temperature.
Reason 4: You didn’t mix enough resin and hardener to start the chemical reaction.
For two-part resin to cure completely, you must mix together a minimum of Part A resin and Part B hardener. That means you can’t mix two drops of resin and two drops of hardener together and expect the four drops to harden.
Reason 5: Using resin and hardener from two different resin kits.
Resin and hardener are specifically designed to go together. Unfortunately, one kit’s resin won’t work with another kit’s hardener.
Reason 6: Water contamination.
Depending on what else you use (resin colors, found items, etc.), they can add water to your resin mixture.
Reason 7: The mix needs more time to harden.
Double-check the cure time for the resin kit you are using. With any luck, you simply need to give your resin more time to cure.
Reason 8: This is normal for polyester resin castings.
Polyester resin is kinda weird in that the surface exposed to air during curing will stay sticky, even after a full cure. And if you’re thinking about using it, here’s what else you should know about using polyester resin.
So, what can you do if you are asking yourself why is my resin sticky?
Here’s how to fix sticky resin.
Wondering if you will ever create anything with resin that isn’t sticky?
Let me help. I wrote the ebook, Resin Fundamentals, with beginners in mind. I’ve condensed my seventeen years of experience into a book of ‘what you need to know’ about resin. I want to help you make something you’ll be excited to show off. It’s all the facts and helpful advice I wish someone shared with me when I started!
Unpublished Blog Posts of Resin Obsession, LLC © 2023 Resin Obsession, LLC
Great information
Can you tell me why my open bangles open up as they get warm and flexible?
I used Art Resin
That resin, even when fully cured, can soften with body heat. The Resin Obsession super clear resin is what I use. It cures crystal clear and stays hard after curing. You can find it in several sizes in our store here:
https://shop.resinobsession.com/collections/resin/resin-obsession
I’m a newbie and bought UV Resin online – the foreign one. I cured with a lamp and stick. What resin can I buy to brush onto polymer clay beads and also use on acrylic painted rocks?
You want to use a doming resin. We have several in our store here: https://shop.resinobsession.com/collections/resin/doming
I made a few pieces of resin in 2 molds two nights. I had started this project the night before that. I checked my pieces and one is a tiny bit sticky in the mold but only at the very bottom of the mold. I had mixed a little bit more resin than I needed and filled 3 small cavities with the extra resin. I am hoping I can remove them all tonight and fix that one very small piece. I’m pretty sure it was because of what you said in the video. I’m a newby and have surprised myself that so far all of my pieces have hardened even when I didn’t think some would. That is why I like Resin Obsession. I learn so much.
I have a resin piece that seemed fully cured knock on it hard for over a week. I went to actually mark it for sale and then it was suddenly sticky – do you know why this could have happened? Please?
What else was included with the resin? It sounds like something else may be affecting the resin.
Hi, I have the same problem. My inclusion was coffee beans. It has not cured again since, and that was several weeks ago.
Dried coffee beans, that is.
I put resin over rocks. My first set I did look like glass but the 2nd batch I did just looks like a good sealer. What could be the problem?
Hmmm Stephanie. That sounds unusual. I think this situation is best suited for a one-on-one consulting call where you and I talk back and forth about what’s going on. A 15 minute consultation call is $20. I do them by video so I can have a chance to see what you are working on. If you are interested, please send a message through the ‘contact us’ page and I can get this going for you.
I saw a tutorial where the lady mixed one ounce of resin with half an ounce of hardener and it came out fine is this acceptable?
It depends on the resin. Some will mix 2:1 like that. The resin kit instructions should share that information with you. This article explains more: https://resinobsession.com/resin-frequently-asked-questions/how-to-measure-and-mix-epoxy-resin-and-hardener/
I’m skeptical of weighing resin and hardener as opposed to measuring volume. Some hardeners and epoxies have different weights resulting in a ratio different from 1:1
Yes Barbara, you are absolutely correct! It’s always best to follow the manufacturer instructions for mixing resin, which usually means measuring by volume.
Why is resin in a bottle premixed still sticky
Hi Peggy, I don’t quite understand your question. Resin should not come ‘premixed’ to you in a bottle. Can you tell me more?
Hi KatherineT
Thank you for responding the bottle says UV Resin Hard, just use it straight from the bottle, my first attempts failed miserably. One bracelet had bubbles and the other the flowers rose to the top. Now im trying to find the right sandpaper to softly sand the bumps out, I find it very conflicting as U Tube has many different ways of using the resin to make the bracelets. There does not appear to be videos for hard resin I see a lot where you have to mix too products together to make the bracelet. I found it hard to get the resin in the mould as well not having the right tools.
Hi Peggy, it sounds like you are using UV resin? Do you have to use UV light to cure it?
The more I read the more confused. In your video on putting a picture between two pieces of packaging tape: after you cut them out you just laid them on your project and poured resin over them? I thought they had to be glued to the project, dried thoroughly and then resin. You didn’t glue yours?
Hi Gail, I don’t glue my papers in place when I’m using the tape method. Rather, I use a toothpick or stir stick to push them into place. Does that help?
Hello and how are you. i have used a mold making kit called amazing rubber mold and for whatever reason all the piece i made in the molds came out sticky but not the resin pieces that i used in other molds using the same batch or resin, the molds are for whatever reason oily at least thats what they kinda feel like. Is there any way i can fix this issue, the manufactures dont seem to have any solutions and the resin i used was made by the vompany too. i bought 3 boxes and it almost seems like a waste of money. Can you help me?
Hi Kyana, I’m afraid I don’t know of a way to fix molds that come out sticky.
Hi! I need help with my problem. It was my first time putting dried flowers in my resin. At first it turned out good then I added the final coating. I noticed it did not fully cured. It’s like it got wet at the middle(the other side is hard). I though my sister might accidentally got some drops of water in it. I tried using flowers in my resin again in another project and it was wet at the middle part again. What might be wrong with it? Please help me, I’m really having a lot of trouble about it. Thank you so much!
Hi Anj, I’m sorry this is happening to you. Was your flower fully dry before using it in the resin?
hi so my question is, when it’s sticky on the sides should re layer it inside the mold? or how since it’s on the side of the mold
Hi Nicole, you have a couple of different options. I discuss them in this article: https://resinobsession.com/resin-frequently-asked-questions/how-to-fix-sticky-resin/
I’m having a hard time getting my resin to cure.
1) it’s typically my clear resin with only glitter in it. This suggests to me that I’m not mixing it as well as my colored resin…
2) I live in a cold climate at times. I’m wondering if my temps are effecting it? I keep my home 72 during the day and 65 at night. Is the 65 too cold?
I’ve made probably 20 different projects and have successfully cured like 5 or 6. I’ve really tried different resins, tried mixing better, tried having the fireplace on. The only constant thing is turning my house down to 65 at night. Is that likely my problem?
Any other suggestions?
Hi Jen, resin not curing is so frustrating! Have you read this article yet for reasons why your resin didn’t cure? https://resinobsession.com/resin-frequently-asked-questions/12-reasons-why-your-resin-didnt-cure/
Hi, I just wanted to share a tip about UV Resin that Ive noticed. I read a few comments about sticky resin with certain molds. Ive found that clear molds work best with UV Resin. If the mold you use is not fully transparent then the UV light cant penetrate it effectively from every side. If the pieces are hard on top but still sticky at the bottom of the mold and your mold isnt clear then thats probably the issue. UV Resin + Clear Molds= Sticky-free Success!