Lids and Calipers
Getting a lid to fit - and fit well - is no easy feat. Practice, practice, practice, and a caliper is what's needed from your first lid onward. See Lid Tips below...
Made from a aluminum with rust-free hardware, these calipers are extremely lightweight and easy to handle. They can be used to measure both the inside and outside dimensions, depending on your piece and the type of lid required.
The Lid Master provides a simple way to accurately measure lid size in one step. For example, to make a drop-in lid, use the smaller end to measure the opening of the piece, as shown in the photo. Once that's done, the other end of the lid master has the lid's measurement!
Lid Tip 1
Clay Shrinks, Make Lid and Piece Together; Or Measure For Lid
It's a fact of clay that it shrinks. When it comes to lids, it's essential to keep that in mind. If you don't make your lid at the same time as your piece, the piece will have shrunk when you go to measure it, for example a few days later. Consequently, the lid won't fit: once both pieces dry, the lid will be too small! Ouch: you will have wasted your time, and lids ain't easy.
So, if you run out of time, like the studio is about to close on you, measure for the lid and record its required size before you wrap up the main piece. Just take your caliper, measure how big the lid needs to be, lock the caliper with the wing nut (make sure it's really secure), and trace the caliper ends onto a piece of paper. Then, at a later time, when you make the lid, simply size the caliper to your recorded measurement. To do so, open and position the caliper exactly over the traced image you made. This way, you can make your lid at a later time, but you will have captured it's size before shrinking commences.
Lid Tip 2
Make two lids, at least, for every piece. Here'w why...
- Practice makes perfect, and nowhere is this more true than with lids. Lids are tough, and take a while to master. The more lids you make, the better you'll get, and the more likely you are to make lidded pieces. It's no coincidence that most pottery studio shelves are filled with lid-less (and handle-less) pieces. So if you're a little lid-phobic, keep on lidding...
- Lids, unfortunately, have an annoying habit of breaking. If it's a functional piece like a sugar bowl or teapot that you hope to use for years to come, make a spare one in case it's needed.
- Even with a good caliper, like those above, measuring a lid can go awry. Maybe you didn't tighten the wing nut enough, or too much. So occasionally a lid just won't fit, and it's hugely disappointing. To avoid this problem, measure and throw your lid. Then repeat, by re-measuring and throwing a second lid, maybe even changing the style a bit. When you're at the trimming stage, you can choose the lid that fits best, opting to toss the other in the slip bucket.
Need to remake a lid?
Use our clay shrink calculator to calculate how large to make your lid based on the finished piece in the current state. This can work if you have the same clay body, will fire the new lid to the same cone temperature, and know the shrink rate of the clay for the piece's current state (completely dried greenware; after bisque; or, after glaze firing).