But I don't want to get into an argument with you, I choose to line my boxes with food grade plastic (feed bags), you go ahead and use them bare, no problem.

What I will agree with is that using a feed bag to line any wooden planter or raised bed is a nice idea because I think it will add a few more years of life to the build as opposed to having dirt directly against the wood. So, that's a good idea in my opinion.
Taking that concept just a step further, I was thinking about how I have made a few sub-irrigated planters with a water reservoir in the bottom. One of the major costs to that design is that you need to use a heavy rubber pond liner or plastic liner to make the waterproof reservoir. I was thinking a feed bag, or two, could be used to line the bottom and sides of the wood planter to smooth out any rough edges or splinters in the wood, then put the plastic liner in on top of the feed bag(s). That should allow you to use a less expensive plastic liner, which should last longer on the smooth feed bag surface, and save you more money.
