I've also made a humidor - mine was out of walmut and lined with spanish cedar. If you want to see some pics, look in the photo albums. Here is what I took awya from that experience:
1. Pine will be too soft and alos pine tends to be milled with A LOT of moisture, even kiln dried has this issue. Save the pine for a bookcase.
2. Solid hardwoods, such as maple or walnut work well but still will expand and contract with moisture. Also, most lunber still has some moisture and over time, it will dry and contact thus ruining your seal. When I built mine, it kept RH like no ones business but after several months, started to lose it's seal. I had to put some electtrical tape over the seal and now all is well.
3. Build it out of a hardboard, such as good plywood or MDF and put a nice veneer on it. Not only it is cheaper to do this, but less expensive and you can use exotic veneers for a good price. This is what I will next time I make one.
4. Lastly, buy 4/4 Spanish cedar and resaw to 1/4 thickness yourself. MUCH cheaper than buying 1/4 pieces from say, Rocklers.
Hope this helps and BTW - Ken's humidors are really nice.... he is the guru.
