Soft or Sticky Epoxy – Resin Troubleshooting
Soft or Sticky Epoxy – Resin Troubleshooting. Once passed the curing timer, if you note that your resin remains sticky, it is very likely that you did not follow strictly the ratio indicated, or that the mixture of part A and part B was not perfectly homogeneous.
As you may know, POLYMERES TECHNOLOGIES has nearly 25 years of experience in the formulation of epoxy and polyurethane systems.Since quality control is the basis of our success, we test our products on different typical and physical aspects such as pot life, viscosity, exotherm, density, hardness, and more. We mix parts A and B of the retain lots and polymerize them for QC purposes. Then we keep liquid retain lots in our laboratories for 2 years.
it’s not until the Quality Control team has approved the lot that we packaging it. So, when the CHILL EPOXY™ products leave our warehouse and ship to your location, you will receive a high-quality product which meets all our quality control specifications. 100% OF THE TIME.
Upon receiving our raw materials, we make sure to get the COC (certificate of conformance) from the manufacturers ensuring the product is on point. However, we sometimes receive information from our customers saying the CHILL EPOXY™ product hasn’t fully polymerized or has some soft spots at certain locations on the part.
If the product has not reached full hardness, has soft spots or, is not curing properly, it can be caused by a few things:
- Ratio not precise (weight or volume)
- Mixing process isn’t done properly causing the molecules to not be 100% homogeneous, so the molecular chain is not fully closed causing less SHORE D (hardness), less heat resistance, and soft spots.
- Mixing the resin for a minimum of the recommended time is imperative
- The sides and bottom of the flat mixing cup should be scraped regularly to remove unmixed epoxy.
- Use professional tools to mix your resin such as flat metal spatula and jiffy mixers. Avoid spoons, forks, popsicle sticks, 2 x 4 studs, brooms; we have seen it all… trust me!
- Temperature: each F/C under 72F/22C will slow down the curing process by 15-25% depending on mass.
- Did you use the appropriate part B for the appropriate part A?
- Don’t use parts A and B from different systems, the stoichiometry will change and the resin will not cure.
- Do not use dirty tools or/and dirty pails because they can contaminate your resin and cause problems.
- Do not mix small quantities such as few milliliters or grams of the CHILL EPOXY™ products because a small percentage error on the mass/volume of resin will represent a large percentage difference on the ratio in volume/weight and this might affect the hardening of the resin.
3 milliliters error on 30 milliliters equals 10% and this will greatly affect the curing process.
3 milliliters error on 300 milliliters equals 1% which is totally acceptable.
Make sure you follow these recommendations to succeed in your project and avoid loss of resin, wasted time, and frustration. Nearly 100% of the problems come from bad weighing, measuring, and mixing.
DISCIPLINE IS THE FUEL OF ACHIEVEMENT…POLYMERES TECHNOLOGIES