Pebbles by Beth Rosengard. Diamond and black drusy garnet earrings.
On my ever-growing list of more advanced metalsmithing techniques to try, casting–specifically broom and cuttlefish casting–is near the top. The surprise and randomness of the results appeal to me just as much as their natural beauty, and I appreciate the fact that the resulting textures, patterns, and shapes really can't be achieved through any other metalsmithing techniques. So if you're up for a little adventurous metalworking and aren't afraid of surprises (or fire . . . ), join me in learning broom casting!
Broom Casting Tutorial
by Brad Smith
natural-bristle broom (straw or corn stalk)
about 1' of binding wire
metal (silver or gold)
crucible for melting metal
carbon rod or clean solder pick
torch with a large tip
clean 5-gallon bucket
You can learn more about broom casting and see examples of broom-cast metal jewelry in the complete article, Casting Metal with a Broom by Helen Driggs (in the June 2007 issue of Lapidary Journal Jewelry Artist magazine). Helen interviews Beth Rosengard, a metalsmith and jewelry artist who has, as Helen accurately puts it, "transformed this delightfully low-tech approach to molten metal into a sophisticated level of artistic expression."
Autumn brooch by Beth Rosengard. Koroit opals and citrine.
The Swan by Beth Rosengard. Necklace of baroque freshwater pearls and diamonds.
Like Helen, I got excited by the possibilities of modifying the broom-casting technique (as I usually do) into other kinds of metal castings, such as shells, twigs and bark, or maybe even moss. "You can use anything that will burn," Beth says. "And the material doesn't necessarily have to be bundled. For instance, you could pour molten metal over rice! Some materials might burn too fast, though, even when wet–like ferns." Okay, maybe moss won't work . . . but I'm still going to try! The idea of experimenting and creating unique shapes appeals to Beth, too, who admits that she "poured molten metal into a bucket of ice and ice water" and "got some very cool, organic splat shapes." I bet!
Broom-Casting Tips and Safety
- Beth shares the value of doing broom-cast pours with a partner, who can help with adding the borax flux or dousing the broom after pouring.
- You can broom cast with "any metal that you're able to melt to a liquid state: in other words, any metal that you might use in lost-wax casting," Beth says.
- Start with silver as a beginner, and if you really want the look of broom-cast metal in gold, you can plate it or thin the silver and "then use lost-wax casting to reproduce them more efficiently in gold," Beth says.
- And what about broom-casting safety? "First and foremost: pay attention to what you're doing and where you're pointing the torch," Beth says. "It's all too easy to lose concentration and burn yourself or someone else."
- Beth recommends doing broom casting outside, preferably on concrete. "It's possible to miss the broom or bucket occasionally," she says, "so stand back and watch out for spraying bits of hot metal."
- Remember to douse the broom after each pour to keep it from burning up too quickly as well as to keep you from getting burned when you pick through it to find your cast-metal pieces.
- As Brad says in his tutorial, broom casting is a metalsmithing technique best done outdoors, "because wet straw is very 'aromatic' when burned!"
- Beth's final words of wisdom for beginning broom casters: "Wear goggles to protect your eyes. And wear shoes!"
To learn more about casting and all kinds of other metalsmithing techniques, check out Lapidary Journal Jewelry Artist magazine–and back issues are on sale now in the Jewelry Making Daily Shop!
Do you broom cast? What metals do you use? I'd love to hear more about your broom-casting experiences in the comments below.