Little Tree Library Dry Shelves

Little Free Library with new shelves on the kids'/sidewalk side.

The Little Tree Library has a small problem. Sometimes when there's a heavy rain, the rain gets inside. If the books are sitting down on the bottom of the library, they can soak up the water and get damaged. Hardcovers tend to be fine, because their pages are raised up and their covers are apparently able to handle a big of damp, but the paperbacks soak up the moisture and either stick together and mold or bulge out into funny shapes as they dry. I don't mind reading a funny shaped book, but I don't feel that good stewards of the library should let the donations suffer like this. The best solution would be a very slightly raised shelf inside for all the books, preferably one that covers the whole of the library floor. Well, the best solution would be to plug the leak, and we're working on that, too, but we've made adjustments to the top several times and we're pretty confident in the door seals, so a shelf seems like a wise precaution, too.

stack of shelves after bisque firing

We'd been vaguely on the look out for a shelf that would work for a few months, and had a temporary Rubbermaid lid inside the library for a while, but when we took out the lid to clean the library one day, we discovered that there had been moisture collected underneath (and turning brown) for some time. We figured we'd better start looking in earnest for a shelf, but that was about when stay at home order started, so all opportunities for looking for a shelf were at an end. And this isn't really a standard item we're looking for, especially since it can't be too nice or it is likely to get stolen. So I figured the most efficient way to handle it would be to make a shelf (or shelves) out of clay.

underside of a wet clay shelf before firing

Over spring break, I rolled out some slabs, perforated them and added lots of little feet. I used some scrap reclaim clay because they didn't need to be pretty and cut out some holes, more or less at random. I want the shelves perforated for two reasons. One, I don't want water collecting on top of them and two, I wanted to minimize the opportunities for cracking during building, drying, and firing.

stack of bisqued ceramic shelves

I rarely make anything large with slabs and never a big flat shelf like this. My students, on the other hand, often try to make bit flat bases for various sculptures and they usually crack. (I do tell them they are likely to crack, but sometimes students need to try it themselves.) The cracks happen for a number of reasons. The flat slabs don't dry evenly, especially if they are left on a board and have lots of clay built up on top. This tends to mean the top and outside edges dry and shrink before the inside, thus causing cracks as the wet interior tries to shrink against the already dry outside edges. Flat slabs also tend to dry into a curved shape for the same reason. The top dries and shrinks first, pulling the wet bottom up into a slight curve. This can be prevented by drying slabs between boards, or by drying more slowly.

Drying shelves between boards to eliminate warping and cracking

Flat slabs also sometimes have trouble shrinking during firing, because their weight holds them down on the kiln shelf causing cracks during firing. Clay shrinks as it changes from wet to dry and again as it changes from dry clay to fired ceramic during firing. As it shrinks in the kiln, it has to move a bit. Usually this isn't a problem, but a heavy flat slab may have trouble moving across a solid shelf and may therefore crack. Sometimes artists put silica sand down on the shelf so that the slab can shift along the surface as it shrinks, but a foot or concave space under the slab can also help prevent cracks. 

picking up a wet slab of clay with one hand like I am doing to the fired work above, can cause cracks to happen during drying or firing

The cracks that show up during firing can also be from uneven drying or from rough handling before firing. Picking up a wet slab or plate from one edge when it is slightly soft can stress the clay and cause cracks to happen later, during drying or firing. My perforations helped lightened the slab and gave it more airflow, but I also made a point of sandwiching the pieces between two boards when flipping them and while they dried to reduce stress on the slabs and prevent warping.

loading up the new shelves in the little free library, they could certainly stand to be a bit larger

The many, many feet are designed both to distribute the weight of the slab (and books) to mitigate cracking and because the floor of the library is not perfectly flat. I figured lots of little feet can hit the library floor wherever it is highest and the shelf is less likely to wobble. Also I like how the feet look. Of course the main purpose of the little feet is to lift the shelf out of the water if the library leaks again.

books on shelves on the adult/street side of the little free library

I made four shelves which together are a bit small for the library. I fired them just to bisque without any glaze because I figure they are pretty likely to get stolen or broken. Making them more attractive is only likely to bring about their earlier departure or destruction. These shelves were pretty easy to make, so I won't mind too much when I have to remake them, though I'd prefer if it wasn't right away. The only disadvantage of the bisque ware is that it will absorb the water, which could conceivably be a problem if we have a leak followed by freezing weather. If these last long enough to get to freezing weather, I'll consider it a win and glaze the next set.