My plug is done and I'm about ready to lay up a mold. This will be used for prepreg so I'm using premium resin tech rdr-1902 high temp surface coat and rdr-3212 resin. I have some concerns with the surface coat. It's a bit thicker than I imagined but I guess that's good so it won't run, however after mixing a small test batch, it seems pretty slow to release air bubbles. As you can see in the pic of my plug, there are areas with vertical walls and even a few areas of negative angle. For air to release from the surface coat as I brush it on, these bubbles need to rise to the surface to pop right? So any areas that are beyond vertical with a negative angle, I would think are gonna have a hard time releasing air. I picture a bubble just rising up against the surface of the plug and staying there. I'm wondering if I should apply the surface coat in partial areas with the plug oriented so surface coat I'm applying is face up, allowing better release of air bubbles.  Do I need to bother? Or can I just brush it on the whole thing as it sits in the pic? Looks like pics got rotated 90 degrees, the pointed nose is up

Yeh most epoxy surface coats are very thixotropic like that. The general technique is to cut the bristles on your brush to about 1" long, so they are quite stiff. Remember to pull the bristles a bit after to get rid of any loose ones. Then brush on a very thin coat, especially in corners, so that you dont trap any air on the surface. From there you can apply a heavier coat, and unless you go really over the top (which wont feel logical, so you won't), porosity shouldn't be an issue.