On Monday, August 8, 2016 at 12:46:31 PM UTC-4, wrote:
Did you ended up sanding it? J know this post is old but I would like to know what results you got. I poured epoxy over my countertops and they look pretty good, the only bad part is that on the back part that touches the wall you can see drip marks. I am not sure how to fix it.

I'm not sure how general your question is, but I can attest that sanding "works" for drip spots. I had some epoxy drips from the bottom of a table. Random orbit sander, 60 grit... chewed right threw it down to the wood.

It sounds like your application might be a bit of a tight spot, in which case hand sanding or larger sanding might be out of the question. Dremel might be more along the lines of what you're looking for? I'm not sure how fine their grits go... I'm only seeing 240, but I've heard you can DIY wheels as high as you like.