Luke,
Your thread had dropped off the first page. Gotta remedy that.
I'm starting to think about a keel restoration. It won't make it this spring, but I was about to buy some more epoxy, and that started me thinking about planning supplies for the keel project next fall.
I've skimmed through your process and Stingy Sailor's, and a few other threads here and there. If I understand correctly, you chose to fair with epoxy + low-density filler (e.g. West 105 resin + West 407 filler). Whereas Stingy used polyester. What factors did you consider, and what drove your decision? (Apologies if I missed that somewhere in your close to 40 pages...)
Stingy said he used about 3 gallons of filler, and it looks like polyester is about $50/gal. If I counted right in your posts, you used something like a gallon of epoxy on yours (at ~$125ish/gal including hardener + filler). So somewhat comparable in price, but maybe he needed a lot more volume to repair and fair his? (3 gal vs your ~1 gal resin + .2 hardener + filler)? How much volume does an ounce of 407 filler add? Or, to ask the question another way, how many ounces of 407 would a gallon of resin require, and what would the net volume be (at appropriate densities for keel fairing)? West System's instructions say peanut-butter consistency is about 35% filler by weight, but don't say what that is in volume.
If the cost for epoxy comes out in the same ballpark as polyester, I'd definitely use all epoxy, but if it's 3x the cost, that'll take a little more convincing (obviously, with neat epoxy first to seal the cast iron, and some more at the end to encapsulate everything). Thoughts and recommendations?