To be more confident in mixing up large amounts of epoxy, it is important to understand a bit about the chemical reaction that occurs.
When the Resin (Part A) and Hardener (Part B) are mixed, they start to cure through a chemical reaction that produces heat. When left in too large a volume, the heat will rapidly build up, and the reaction will start to accelerate, which produces even more heat. This is known as a runaway exothermic reaction. In some instances, the temperatures of the epoxy can reach in excess of 250 F and produce noxious fumes. The end result is wasted material.
To avoid this issue, mix smaller batches that can be easily applied within a few minutes. Additionally, a longer pot life can be achieved by pouring the mixed material into a larger container such as a paint tray. This spreads the volume out, reducing heat buildup.
Listed Below are our products categorized by reaction speed (which determines exotherm) and our recommended maximum batch size at room temperature. Keep in mind that warmer temperatures will cause the epoxy to cure faster, while cooler temperatures will slow down the cure.
As you gain experience in safely handling the mixed epoxy, larger quantities can be mixed.
Super fast reacting products, maximum batch size = 2oz:
- Quick cure 5/15.
Fast reacting products, maximum batch size = 6oz:
- General Purpose with the #1 Fast hardener.
- Silvertip epoxy with the Fast hardener.
- RotFix.
Medium reacting products, maximum batch size = 16 oz:
- General Purpose with the #2 Medium Hardener.
- Silvertip line of pre-filled epoxy compounds (except EZ-Fillet).
- Cold Cure.
- T-88.
- Blade Pro.
Slow reacting products, maximum batch size = 32 oz:
- General Purpose with the #3 Slow Hardener.
- Silvertip With the Slow Hardener.
- Clear Coat.
- MirrorCoat.
- Mosaic.
- G-2.
- EZ-Fillet.
- Sculpwood Putty / Paste.
Very slow reacting products:
- MirrorCast = 1 gallon.
- RiverCast = 15 gallons.
How do I mix large volumes of epoxy?
Comments
Q - are the ounces weight or volume? Weights in metric would be handy.
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