Making PMC silver metal clay oil paste

Art Clay Silver™ Oil Paste is an excellent commercial product that creates very strong bonds between previously fired pieces of silver metal clay, or between fired silver clay and other types of fine silver metal (wire, sheet, settings, findings, etc.). It has a somewhat stickier consistency than homemade PMC® lavender oil paste, which gives it a bit more "grab" to hold the metal parts in place until the paste dries. Both Art Clay Silver Oil Paste and homemade PMC lavender oil paste can be used to join fine silver metal (including fired pieces made from either brand's fine silver clay).

Since Art Clay Silver Oil Paste is such a good product and is conveniently ready to use straight from the package, why would a metal clay artist bother to mix up homemade lavender oil paste? There are some situations in which homemade PMC lavender oil paste may be preferable to Art Clay Silver Oil Paste:

• One of the main differences between commercial and homemade oil paste is that Art Clay Silver Oil Paste should be used only to join fine silver metal (previously fired silver metal clay pieces, fine silver wire, fine silver sheet metal, etc.), whereas homemade PMC oil paste can be used to create strong joins between pieces of silver clay greenware (including PMC Sterling™ and PMC Pro™), to attach greenware to silver metal (including fired silver metal clay). or to join pieces of silver metal (including fired silver clay).


• Another difference is that Art Clay Silver Oil Paste must be fired either at 1472ºF for 30 min. or at 1560ºF for 10 minutes, whereas homemade PMC lavender paste made with fine silver PMC can be fired at any of the recommended firing schedules for PMC, including at 1650ºF for 2 hours (for fine silver greenware or metal), which not only create the strongest possible bond with the oil paste but also ensures that any greenware is sintered fully.
  Important: Because of the unique composition of Art Clay Silver Oil Paste, even at the lower firing temperatures and shorter firing times, this formula produces extremely strong bonds between pieces of fine silver metal (including fired fine silver PMC clay), which is the only purpose for which it should be used. The ability to fire hotter and longer is relevant only when using oil paste to attach greenware.
• Because of the flexibility in firing schedules, you can use PMC lavender oil paste to attach sterling silver earring posts, bezel cups, or other sterling silver findings to silver metal (including fired silver metal clay) and fire at 1300ºF for 30-35 minutes (something you can't do with Art Clay Silver Oil Paste, which requires a higher firing temperature).
  • Note: Attachments made with homemade PMC oil paste and fired at this lower firing schedule for sterling silver will not be as strong as soldered joins.
• You can make homemade oil paste from PMC Sterling or PMC Pro slip, which is much stronger than fine silver metal clays. See "The Strongest PMC Oil Paste," below, for firing schedules.


• Some people react badly (headaches, nausea) to the fumes from Art Clay Silver Oil Paste, which is a petroleum-based product. Some just don't like the odor. And others prefer to avoid breathing petroleum-based fumes for health reasons. Homemade PMC oil paste is made with 100% pure essential oil, and while lavender oil is the most commonly used choice for PMC oil paste, another plant-based essential oil may be substituted for those people who don't like its smell.


• The petroleum-based component of Art Clay Silver Oil Paste is incompatible with the organic binder in other forms of silver clay (PMC or Art Clay Silver), whereas you can add metal clay dust or scraps and a little water (along with more essential oil) to PMC lavender paste, just as you can with plain metal clay slip to replenish the oil paste as you use it up.


• PMC oil paste can be mixed up whenever you need it, in whatever quantity you need, so you never have to worry about running out.

I have used Art Clay Silver Oil Paste with excellent results to repair breaks in fired pieces or to add fine silver findings, settings and wire to fired pieces. As I mentioned previously, it's ready to use straight from the package, and has the advantage of being a bit stickier than homemade PMC oil paste. I've also had excellent results with homemade PMC lavender oil paste, and I like its versatility and the fact that I don't need to worry that it will dry up or that I'll run out.

To sum up, either type of oil paste will create strong (fine silver) metal to metal joins. If you need to join pieces of greenware together, or to join greenware to metal, then you'll need to use homemade PMC oil paste.

Making homemade PMC oil paste is fast and easy. Here's how:

Step 1. Start with a small jar of plain PMC3™ silver metal clay slip, or mix up a similar amount of slip from PMC Sterling™ or PMC Pro™. Mix tincture of lavender (essential lavender oil diluted with alcohol and sometimes water) or 100% pure essential lavender oil (or another 100% pure essential plant oil; see Don't Love Lavender?, below) and water into some plain silver clay slip, a few drops at a time, stirring with a palette knife until it is smooth and creamy.
• If you are using a lavender tincture, start by mixing in 5-10 drops, or if you are using a 100% pure essential oil, start by mixing in 3-5 drops of essential oil and then adding a 1-2 drops of water.
  • Note: Some artists also add a small amount of isopropyl alcohol as well as water if they are using 100% pure essential oil rather than a tincture. (The alcohol evaporates as it dries, but I find that it makes the paste a bit creamier.)
Step 2. Continue adding drops of tincture (or 100% pure essential oil and water, and alcohol if you're using it), adjusting the proportions a drop or two at a time, until you have a very thick, very creamy slip that smells strongly of whatever essential oil you are using.

Step 3. Cover the mixture tightly and allow it to sit overnight.

Step 4. Stir the homemade oil paste well before using.

Tip: There is no precise recipe for making homemade oil paste, and of course the amounts of the oil, alcohol and water you add will depend to a large extent on how much plain slip you start with. As a frame of reference, when I'm making homemade oil paste from a new, 15-gram jar of commercial PMC3 slip, I usually add about 25-35 drops of lavender tincture, or about 15-25 drops of pure essential lavender oil, about 5-10 drops of alcohol, and just enough water to get the consistency I want.

Tip: When purchasing 100% pure essential oils or tinctures, make sure you know whether the bottle comes with a standard bulb-type dropper cap or a European "dropper orifice" ( i.e., the opening of the bottle acts like a built-in dropper). If the bottle doesn't come with a dropper, you'll need to buy either a dropper cap (make sure it fits the bottle!) to replace the original cap, an eyedropper, or a pipette that you can use as a dropper.

Note: You may want to work in a well-ventilated area if you are sensitive to the smell/fumes from the essential oil you are using. Celie Fago. who is sensitive to the strong smell of 100% pure essential lavender oil, stores her prepared lavender oil paste in a room other than her studio.

Important: When making homemade oil paste from any PMC clay formula, be sure to use either a 100% pure essential oil or a pure essential oil tincture. Do not use an essential oil blend that contains carrier oils, such as jojoba, sweet almond, grapeseed, olive, avocado, sesame, evening primrose, sunflower, canola, emu, castor, or nut oils, Carrier oils are used to dilute essential oils before applying them to the skin for aromatherapy or massage. Cooking oils or carrier oils do not react the same way with the paste as 100% pure essential oils or tinctures made from pure essential oils, alcohol, and water. In fact, small amounts of carrier or cooking oils can be mixed into lump clay to make it flexible, which also makes the clay stick to itself less readily - the opposite of the desired effect..

Many people are allergic to (or just don't like) the strong smell of lavender pure essential oil. A number of artists have substituted a different pure essential oil (including peppermint, grapefruit, and rosewood oils) successfully.

Helpful resources

• Lavender oil is available from most metal clay suppliers.
• Tincture of lavender is available from Purple Haze Lavender Farm.
• Other essential oils are available from health food and aromatherapy supplies stores.
• 100% Pure Essential Oils offers literally dozens of different pure essential oils.
• Donna Lewis of Metal Clay Arts recommends Ulta, which carries peppermint, grapefruit, rosemary, and tea tree essential oil as well as lavender oil.

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