General resin trouble shooting tips
When working with resin, technique is very important to ensure outstanding results. Here are a few of the commonly encountered resin jewelry making problems and some possible explanations:
Resin not cured or has not fully cured:
1. Resin was not mixed in the correct ratio of resin to hardener. Recheck instructions and measure both parts separately and accurately in graduated mixing cups.
2. Resin and hardener were not mixed thoroughly. While mixing, it is important to scrape the sides of the mixing cups and stir utensil during the process to make sure the mixture is well blended.
3. Non compatible resin and hardener used. Be sure to use a hardener that was designed for the resin you are using. Not all resins will work with all hardeners.
4. Hardener not added to the resin. In order for the resin to cure, a hardener must be added.
5. Not enough time given for curing. All resins have different cure times, from minutes to hours to days. Check to be sure you are giving the resin enough time to cure.
6. Resin is not warm enough or the room in which the resin is being mixed is not warm enough. The resin and hardener, along with the room temperature, needs to be about 70 degrees Fahrenheit. Warm the resin in a warm water bath in 5 minute increments if the resin bottles feel cool to the touch.
7. Resin or hardener is past its shelf life.
8. Resin is poured in a thin layer. Thin castings will take longer to cure than thicker castings due to overall less heat production.
9. Too much moisture in the resin casting. Use colorants designed for coloring resin and use resin kits within their specified shelf life times. Also be sure all mixing containers and utensils are dry.
Pot life of the resin is shorter than expected
1. Improper resin to hardener ratio. Do not use more hardener or less resin than recommended. Having more catalyst than what is needed will cause the reaction to heat up quickly and cure faster than normal.
2. Resin and/or hardener are too warm. When these are warmer than 75 degrees, pot time is shortened.
3. The amount of resin and hardener mixed at one time is too large. The reaction is mass dependent — the more of each item, the more heat that is produced, the faster the resin heats up and the faster curing takes place.
Pot life of the resin is longer than expected
1. Improper resin to hardener ratio. Make sure to use the exact amount of hardener recommended in order to start the chemical reaction.
2. The resin, hardener or the room is too cold. Be sure the components and the room temperature are between 70 and 75 degrees Fahrenheit.
3. The volume of resin and hardener being mixed is too small. Resins require a certain amount to be mixed in order for the curing reaction to occur. Be sure to mix the minimum recommended amount by the manufacturer.
Cured resin has bubbles in it
1. Be careful when mixing the resin. The best way to make sure bubbles aren’t in your final casting is to avoid creating them when mixing the resin. Carefully and deliberately stir the resin and hardener when mixing, but do not whip it.
2. The resin has reacted to something included in it. Make sure all inclusions are sealed with glue or clear tape before including in resin.
3. Remove bubbles before allowing the casting to cure. Draw them out with a toothpick or use a heat gun to get bubbles to the surface.
Resin is cured, but surface is tacky
1. Resin and hardener were not mixed thoroughly enough. Be sure to mix completely, scraping the sides of the container and stir utensil while mixing.
2. When using polyester resin, this happens to the surface exposed to air during curing. Either seal the side with a sealer spray or sand off the tacky surface.
3. Excess humidity. Run a room dehumidifier during the next casting.
Resin embedments have ‘wet stains’
1. Seal before including in resin. Any item that can take up water needs to be sealed before using in resin.
Resin and/or hardener has yellowed
1. Resin kit is past its expiration date.
2. Resin kit has been improperly stored. Resin and hardener need to be stored in a cool, dry place, away from sunlight and temperature swings.
Resin has cured cloudy
1. Resin kit has been contaminated with water.
2. Resin components are cold. Warm to at least 70 degrees Fahrenheit before using.
What other experiences do you have with resin not curing properly?