Because I work on the large side, and because I box-form many of my wall enamels before firing them, keeping my pieces from warping is one of the biggest technical challenges I have to cope with. I’ve experimented with a number of approaches — before, during, and after firing — and this 6×8 steel planche is one of them.
I got mine from Thompson Enamel for about $30. Their planche consists of two side rails from square steel stock welded together by four cross members of the same steel. The two rails are bent on each end to form feet. On top are 12 little spikes, upon which the piece is supposed to rest. There’s another version available online from Ken’s Gems Supplies in Alberta which looks similar but without the cross members and, consequently, with one-third fewer teeth. The missing cross members would, I speculate, cut down on the weight but make the piece touchier to balance on the fork. This model is also, for some reason, pictured upside-down. But that, I suppose, is slightly more helpful than the Thompson site, where the product isn’t pictured at all. At least as of this writing.
A standard kiln fork slides between the feet on the narrow end. It works, but it’s tottery. Rio’s firing pan removal fork, on the other hand, is more stable, but only fits on the long end. That fork has a longer handle and takes getting used to — mostly because you need more maneuvering room around the kiln — but I prefer it, as the planche itself is kind of heavy as firing racks go, especially loaded down with a big piece. The big fork also has two handles, which means you can use two hands, which means you have more control. It also has a wider support base to carry the weight.
I really wanted this thing to work, and it kind of does, but only kind of. The planche is designed as an enamler’s bed of nails. The idea is supposed to be that the many tiny contact surfaces allow for maximal support (to prevent warping) with minimal contact (to avoid sticking). Sadly, the contact is far too minimal, as no two of the points are the same height. So instead of distributing the support equally, the piece wobbles precariously on only one or two nail heads. Really good theory. Really bad execution.
Between the wobbly contact points, the heavier-than-usual rack, and the too-small fork, my first efforts resulted in an 11×11 piece that nearly slid off the planche. Sizing up on the fork, being a lot more careful to center said fork under said planche, and being exquisitely careful about how I moved the piece into the kiln, made the undertaking doable, but didn’t offer a lot of advantages to simply firing on one of my homemade wire racks or a trivet. In fact, because there’s no enamel-to-rack contact on my home-made version (not with my box-lid enamels), flattening those pieces that did warp was easier with them than on the planche. More traditional flat enamels would be different, though, since they can only be fired with some contact between enamel and rack. In that case, I think flattening a piece on the planche is more viable than flattening a piece on a trivet. But I don’t use big trivets much (yet) so I can’t say.
Maybe it’s harder than I realize to weld a bunch of pins onto a frame and keep them even. Mostly, though, the whole planche strikes me as suffering from sloppy workmanship. Hope springs eternal —
either that or stupid never quits — so I’m buying another, bigger model. That’ll give me an idea if 1: my first planche was just a lemon, and B: a bigger, equally sloppy planche works better simply because more haphazard pins means more contact points by shear dint of numbers.
This planche isn’t cheap, and quality control should be better than it is. It is functional enough, especially if you use an adhesive like klyr-fire, and if you’re careful, which you ought to be anyway. Its primary real advantage over a trivet is size flexibility, its primary theoretical advantage would be stability, but it misses the mark there. In the end, you’ll have to buy several trivets to cover the size range of one of these, so economically it’s probably a wash. But the trivets will be lighter. And they probably won’t piss you off for being crappily constructed.