Cobalt or CoNap, is short for Cobalt Naphthenate. CoNap is used at 6%, 12% or 21% concentrations when promoting vinyl ester and Poly ester thermoset resins. CoNap and DMA (Dimethylaniline) are used to promote resins, typically before it ships from the factory. Once the resin is promoted, all that is needed is catalyst, typically MEKP or BPO to start the chemical reaction required to cure the thermoset. Adding the CoNap, DMA and catalyst at the same time is a very bad idea. Ashland Performance Materials discuss issues with Cobalt and alternatives for the future. Link to this article.