Hi, welcome to Fantasy Life Wiki! Thanks for your edit to the Lava Cave page.
Just like that I don't know, sorry! I have both hero woodcutter and carpenter so I make them myself. If anything I'd recommend checking Al Maajik (not likely), the Mt Snowpeak wandering seller, or possibly the Elderwood shops, but I really can't recall if I saw them sold there or not :/
At least soon you'll be able to look it up on here x)