After visitng Reranch and Buildyourownguitar and Projectguitar a few times, and not being overly bright, I am still a little confused about which type of final clear coat to put on my project guitar. The guitar is alder and is being painted opaque BTW. No fancy pants French polish for me - waaaay beyond my ability. Can somebody here answer a few questions for me? The preferred topcoat seems to be Nitro. Why? Does it shine up better? Does it sound better than Poly? What is it about Nitro that makes it better? Poly seems to be much easier to apply - carefully use a brush and some sand paper. I've refinished some tables over the years and always coated them with Poly. They look nice and shiney and have lasted for, well, years. Why shouldn't I use poly on my guitar? Does it crack or check easier than Nitro? Does it affect the tone more, or worse, than Nitro? Can some of you wood experts please school me on Nitro v. Poly finishes? Thanks in advance for all thoughts and comments.