The whole point of ScavCraft (or ScavengerCraft) is that you no longer have to go mining to get resources. It's still more efficient, but, if you are playing a modpack where you are in, say, an abandoned city, and the whole point is that you go around the world and find stuff instead of mining for it, here you have it. You can scrap nearly anything back down into it's materials, which allows a ton of ways to get your stuff back if you craft the wrong thing, or if you just find stuff out and around the place. I would recommend using this with the Lost Cities mod, because then you can find cities and scrap the stuff around them to get materials back.
The first thing to do is craft yourself a set of Scavenger's Tools, which then you can use in the crafting grid with other items to scrap them down to basic materials. Good luck!