I know at a minimum it's two days for the scratch coat and 2 weeks for the brown coat. But, I just finished the scratch coat this weekend and I probably won't get back to do the brown coat until next weekend. Do I need to continue hydrating it for the entire week it's uncovered? or is it just up until it cures to a point (2 days) and then it'll be OK? Although I'm assuming I'll need to wet it before applying the brown coat. Thanks

I'm finishing up my house re-paint and one thing on my list is the replace the 5' x 2.5' box at the top of my chimney chase. It is made up of 2x12s and the chase cover/cap fits over top of it. One corner is rotted pretty good and the other sides have splitting ends, so I'm replacing it all. I thought the 2x12s were fir, like my gable fascia, but upon closer inspection it is cedar. Won't be cheap to replace with cedar (need 2 pieces of 2x12-8), so I'm wondering if fir will be acceptable. If I prime/paint all sides before install, and caulk/paint any seams after its up, I think it will be fine. Thoughts? Also, any recommendations on construction method? Currently everything is just butt jointed. Was thinking I could build the box on the ground with screwed/glued miter joints, but I'm not sure how much of a pain that will be to install. Gluing miter joints up in the air may be possible, but I may not have the best access to prime/paint anything that is hidden. Thanks! Best pic I have at the moment: [IMG]https://i.imgur.com/CFdJsMq.jpg[/IMG]