I have an infinite supply of 4x4s and get a few 4x6s every once and a while. They're used for shipping plate steel, used in between cutouts as spacers, etc... We get them from steel companies constantly year round. They're all rough cut, so they're not typically 3.5"x3.5", sometimes they're 3.5"x4.5" or 4"x5", etc... Always hardwood, but the species varies... Probably 50-60% Oak, but the rest is anyones guess. I've been burning them the last 2 years, but I keep thinking... there has got to be a better way to burn these. I burn them log cabin style, 4-5 on the bottom N/S, then 3-4 E/W then another 3-4 N/S if I can fit them depending on my ash level. This is usually good for about 30-35 hours. Usually I like to leave 1-2" in between each piece... sometimes it's more because I don't want to pack it too tight. This year I wanted to make sure I had good dry wood so I bought a cord of Ash. Burning this wood makes me dream of getting more out of the 4x4s! I switched to the Ash because even though the 4x4s are Kiln dried, they're still very wet. Usually 18-19% on the outside and 22-23 on the inside. A little too damp for my taste, but they still burn great after I burn it on high to drive out the moisture. With a full load of ash, I get about 60-65 hours @ 20-30F outside temp. So it makes me wonder, how can I burn these 4x4s better. If I stack them all up in there, there is just enough air space like typical cord wood. Should I split them all in 4? But then there's still a flat edge. I figure you guys are the burning experts, so there has to be a better way to do it.