Originally published November 2012. Updated November 2018.
If you have ever used resin only to get less than desirable results, you’re not alone. While resin is a fun and versatile way to make jewelry, it can be a fussy beast as well! These are a few of the most common resin troubleshooting problems and what you can do about them:
1. “Stains” or dark areas on embedded items.
This is when you embed papers or porous items into your resin castings only to see later that the item has stains or dark areas on it like it is wet. This happens when the resin soaks into the paper.
These techniques are helpful for how to papers and other items sealed for casting in resin:
2. Resin castings are cloudy or full of bubbles.
This can happen when the resin reacted with the embedded items. The resin can react with your embedments, especially if you are talking about vintage papers (lots of acid!).
There are a lot of reasons why bubbles can happen in resin. Here are 10 tips for getting rid of bubbles in resin.
Coat embedments in sealant before using.
Make sure the resin in warm before mixing. Put both bottles in a warm water bath for 5 to 10 minutes before pouring. Be sure your containers are dry before working the resin to avoid any water contamination.
Are you trying a new colorant or addition? The resin may be reacting with that item. Once again, make sure all additions are dry.
You can watch some of my best suggestions on how to avoid bubbles in resin:
3. Resin is not fully cured after suggested curing time.
This can be anything from still a bit sticky on top to a big goopy mess.
Follow label directions precisely. Do not add more or less hardener and measure accurately. While it is popular in a lot of other blogs and you tube videos, I never suggest using the caps to the resin bottles as measuring tools. You cannot get an accurate measurement this way. Use the proper size mixing cups to measure and mix your resin.
Make sure your mixing utensils and containers are dry. Resin hates water!
Store your resin in a climate controlled environment. Having resin in an area where there are big temperature swings (such as a garage or storage unit) can allow condensation to form on the inside of your resin container lid. This moisture then drips into your resin.
Make sure you mix the minimum amount of resin needed for the chemical reaction of curing to occur. For example, if you’re working with a 1:1 resin to hardener resin kit, you cannot mix two drops of resin to two drops of hardener and expect it to cure. Resin curing is a chemical reaction that requires a minimum amount of each component for it to occur. This resin casting article contains a PDF link with the information for the resins sold in the Resin Obsession shop.
Mix thoroughly. This video shows you how:
If your pieces end up being just a bit tacky on top, you can try sanding them down and recoating with resin. If your resin is a semi congealed mess, there is not any way to save that resin. You can try to scoop it out of the mold and clean with home improvement store acetone (wear gloves when doing this!) to remove the leftover resin, but it may be easier for you to toss the mold and start over.
4. Resin sticks to my mold.
Assuming your resin is cured, you can try these tricks, otherwise, see number three above.
If cured resin is stuck to your reusable plastic mold, you can try placing the mold in the freezer for a minute. Remove the mold and see if you can ‘slap’ or ‘break’ the resin out of the mold. (You can try smacking the mold on a hard countertop.) If the resin doesn’t come out, you can try putting the mold in the freezer for another few minutes. In my experience, if the resin doesn’t come out after 10 total minutes of freezer time, it’s not coming out.
If the cured resin is stuck to your silicone mold, I’m afraid there’s no way to get that out. However, that brings me to another important point: polyurethane and silicone don’t play well together. Personally, I have never had a problem with properly cured epoxy or polyester resin sticking to a silicone mold. The times I have heard about resin sticking to a silicone mold have always involved silicone and polyurethane where a mold release was not used. Of course if you’re casting silicone into silicone, you will absolutely need to have a mold release, otherwise you will create one large block of silicone.
5. Resin gets hot and cures within minutes.
There is always a little bit of heat when resin is mixed due to the exothermic nature of the reaction and curing. Excess heat, however, will cause the resin to cure very quickly.
Use the proper mixing utensils and containers. While I understand it is tempting to use old plastic bottles, party cups, and styrofoam containers to mix resin, these items have chemicals in the surface that can accelerate the reaction that occurs between the resin and hardener. Try to use plastic cups designed for resin.
Do not add more hardener than is recommended. This will speed up the reaction and can cause the resin to cure very quickly.
Do not mix more than the recommended mixing amount of hardener and resin together at once. This resin casting article contains a PDF link with the information for the resins sold in the Resin Obsession shop along with their minimum and maximum mixing amounts.
What other resin curing problems do you have that you would like advice about?
Unpublished Blog Posts of Resin Obsession, LLC © 2018 Resin Obsession, LLC