The epoxy will act as a magnifier and heat the air inside the foam, that will result in more air bubles...
Yes, the brush is the way to go, but only for 30 min epoxy like Devcon 2 ton, this has a great glossy fininsh, used it on some crankbaits :yahoo:
Try not to lift the bodkin or tooth pick out of the epoxy when mixing it. This willl keep the bubbles to a minimum......