So, those plans went out the window...
Today it was time to pull out the Dremel again. I sat outside on the deck in the 40 degree weather for an hour (today was a warm day, hooray!). Grinding epoxy and resin is very messy, and you will be covered in dust, and you really don't want that in your home contaminating your air. Plastic is messy as well, but it tends to heat up quicker from the friction of the tool, so comes off in bigger chunks. Always wear a good N95 dust mask, you don't want to breathe plastic/epoxy/resin dust (and we've all learned that wearing masks will also help keep you warm when you're outside in winter!).
I removed smaller sections of the neck where the epoxy wasn't shaped exactly how I wanted it, or it got a tad too thick. For this, I used a grinding bit attachment. It will require major hand sanding to smooth the area, and it may get some touches of epoxy to smooth it out, or put detail back in (not sure why I thought using it on the corners of his mouth was a good idea). Being precise in what you need to dremel will save you time in restoring fewer areas (note to self). Sometimes, I'll even mark specific areas with a permanent marker to guide me.
Handy tip: use one of these little grinding stones to clean up your grinding bit head. It's the little block between my fingers. You just run the grinding stone head attachment against it and it will remove the built up epoxy/resin/plastic and reshape your tip.
I ground down a large section of the neck with a sanding drum. This tool has a rough texture (think coarse sandpaper), so takes a lot off quickly. It also leaves a very rough surface behind, so is best to use when you are planning to resurface the entire area with epoxy. You want to take off more to allow room to build back up with epoxy.
I used a reinforced cutting wheel to take the ears and tail off. I am always super careful and wear safety goggles as a broken disk can go flying.
I went back to the grinding stone to carve detail into the head where the forelock and ears used to be. Look at lots of pictures and study anatomy to get a feel for what the structure is and how it should look.
The hind weight-bearing leg needs a little tweaking so that the hoof will rest flat when he's up on pegs. I cut a notch in the pastern below the fetlock with a cutting wheel. Later, I'll use an embossing heat gun to warm up the pastern to align the hoof where I want it. If this change in pastern angle were more extreme, I would also need to move the hock angle (and maybe even the stifle) to keep the joints moving in tandem correctly. I didn't drill holes for his pegs yet either. Better to do that later and make sure I'm precise.