Mixing ratios and mixing of Epoxy and Polyester

Polyester and epoxy resins cure by mixing 2 components together. It is important to weigh the 2 components correctly and mix them properly to achieve the best possible result. On this page we explain to you what the mixing ratios of these resins are and how to mix both components correctly!

Mixing Polyester Resin, Topcoat and Gelcoat

Polyester-based products (polyestertopcoatgelcoat) are generally cured with a MEKP polyester hardener. The dosage of this transparent hardener may be between 1.5% and 2.5%. The amount of hardener added affects the speed of curing. At low temperatures a little more hardener can be added (2.5%), while at high temperatures you should add a little less hardener (1.5%). It is not advisable to add less than 1.5% or more than 2.5% hardener.

The 20 gram and 100 gram bottles of polyester hardener come with a dropper. 1 gram of polyester hardener is approximately 25 drops. We recommend not making more than 1 kg of polyester resin at a time. The higher the volume mixed with hardener, the shorter the processing time. For larger amounts of hardener, a syringe or dispenser can also be used for exact dosing.

Polyester Resin Hardener Number of drops Total
100 grams 2 grams 50 102 grams
250 grams 5 grams 125 255 grams
500 grams 10 grams 250 510 grams
1000 grams 20 grams 500 1020 grams

Mixing Epoxy Resins

Unlike polyester resins, one cannot vary the mixing ratio of epoxy resins. The given mixing ratios should be observed as accurately as possible to obtain optimum properties. The speed of curing can only be influenced by choosing a different hardener or a different temperature.

Mixing ratios of epoxy resins are usually given as 100:xx. This indicates how many parts hardener 100 parts resin needs to cure. This ratio is always in parts by weight. Therefore, to mix epoxy, we recommend that you use a scale. Because the mixing ratio of epoxy is very precise, we recommend not making quantities smaller than 50 grams. The smaller the total quantity, the more precise the dosage should be.

Mixing ratios of RESION UV Resin Art Epoxy (2:1)

Resin Hardener Total
250 grams 125 grams 375 grams
500 grams 250 grams 750 grams
1000 grams 500 grams 1500 grams
2000 grams 1000 grams 3000 grams

Mixing ratios of Epoxy Coating, Epoxy Casting Resin and UV Epoxy Resin (100:60)

Resin Hardener Total
200 grams 120 grams 320 grams
300 grams 180 grams 480 grams
500 grams 300 grams 800 grams
1000 grams 600 grams 1600 grams

Mixing ratio of Universal Epoxy Resin (100:50)

Resin Hardener Total
100 grams 50 grams 150 grams
250 grams 125 grams 375 grams
400 grams 200 grams 600 grams
800 grams 400 grams 1200 grams

Mixing both components

For optimal results, in addition to proper weighing of both components, mixing is crucial. Incorrect mixing can lead to uncured spots, surface ripples, cloudy spots and other abnormalities. When mixing, it is important to especially scrape along the bottom and side of the mixing cup and for critical products that are less easy to mix, such as silicones, epoxy photo resin and the transparent epoxy coating, mix using the 2-cup mixing method. To do this, follow the following instructions:

Step 1. Prepare the work area properly

Have the necessary materials ready. These include:

Be sure to protect the work surface from resin residues, for example with foil.

Step 2. Weigh both components

Turn on the scale and place the mixing cup on the scale. Tare the scale so that it reads 0. Now add the correct amount of component A (resin) to the mixing cup. Tare the scale again so that it is again at 0. Next, add the hardener. Do this carefully with epoxy, because if you overshoot, you have to start calculating how much more resin to add to compensate for the excess. Practice has shown that with epoxy it is better to add a gram too little hardener than too much.

When dosing polyester resin, the dropper or a syringe can also be used. Of course, the scale can also be used for larger quantities.

Step 3. Mix both components together

Now mix both components together in the same mixing cup. Feel free to do this for 2-3 minutes, especially with epoxy. Scrape well along the bottom and sides of the mixing cup.

Step 4. Pour the contents into a new mixing cup and mix again

Pour the entire contents of the mixing cup into a new, unused mixing cup. Mix the resin again for 2-3 minutes, scraping well along the bottom and sides. The resin is now ready for use.

The video below illustrates these steps:

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