I've recently learned about a tip full size kit plane builders use when mixing epoxy. I think you will find very useful:

After you've mixed up a batch, pour it into a fresh container before using it. No matter how much stirring you do, there will always be some unmixed resin stuck to the walls of the mixing cup. Pouring epoxy into another cup will ensure no unmixed resin ever gets on the model.

And here's an epoxy mixing tip from the Jive Combat Team: be sure to mix it.

 

 Howard could not possibly make that mistake, I'm certain it was intended as a potential weight saving measure.