I completed the finish sanding on the Portland guitar body this morning. I then reviewed some videos on the process for grain filling with epoxy, and headed back to the garage, gram scale in hand. I mixed up 10.0g of epoxy resin with 4.4g of hardener, stirred very well, and with a certain amount of trepidation, poured it on the back of the guitar! I smeared the epoxy around all over the back, being careful not to let it run down the sides, working it down into the grain from all directions. I then cleaned up the scraper I was using, and scraped the excess epoxy off the surface, trying to leave a thin layer behind. I suspect that in fact I removed too much epoxy and and ended up pulling a lot of it up out of the grain. I an expectiing to need three coats to really get the grain smoothed over, I hope that is all it takes. Now the guitar body is curing in a closed room in the house where it is a bit warmer then the garage. Tomorrow I will be able to take it out and begin doing the first epoxy coat on the sides. Will try to set it up so I can do both sides in one session.