Duncan Overglazes

       The fired gold, premium gold and white gold metallic overglazes plus the Mother-of-Pearl Luster make up the Duncan Overglaze product line. Overglazes are generally used for decorative fired glazed surfaces.

    Duncan's metallic overglazes are Liquid Bright Gold, White Gold and Premium Gold. Collectively these three metallic overglazes are commonly called Duncan Fired Gold overglazes. White Gold, also known as platinum or silver metallic overglaze, is nearly the color of fine white gold jewelry. Premium Gold has a higher gold content than Bright Gold and the color is slightly deeper, richer and closer to pure gold in appearance. The Liquid Bright Gold has the appearance of fine 18 karat gold jewelry. Metallic overglazes are nearly opaque, and should be used over clear glazed surfaces, or lightly colored overglaze compatible glazed surfaces for best results.
    Liquid Bright Gold, also simply known as Liquid Gold, is used to decorate ceramic wares often with fine lines rather than broad coverage. Liquid Gold has a long history in the ceramic arts dating back into the early 1800's and has expanded into other industries including various electronics, aircraft, automotive and even aerospace.
    The primary suppliers of Liquid Gold over the past many years have been Degussa (Germany), Johnson Matthey (Great Britain) and the Hanovia division of Engelhard Industries (USA). When Engelhard was purchased by BASF earlier this decade the Hanovia division was closed and Engelhard ceased manufacturing their Liquid Gold and their other overglaze products. The closing of Hanovia did cause a ripple through the ceramic arts, but because Duncan Enterprises has used Johnson Matthey as their exclusive supplier over the past decades, and Duncan (and in turn Dogwood Ceramic Supply) was able to continue to offer Liquid Bright Gold with no interruption while the Hanovia product line is slowly sold off the market.
    The actual formula for Liquid Bright Gold is a solution of gold dissolved into an organic acid and then suspended into a thick solvent based solution for ease of application. Additional heavy metals, such as rhodium, indium and even platinum can be added to the gold solution specifically to increase or improve the glossy appearance, surface hardness, color, thickness of the fired result as well as to increase the finished adhesion to the glaze or glass substrate. The actual amount of gold in the solution can range from a few percentage points to as much as 12%. The higher amount of gold in the solution is not always automatically the better product, and as such higher gold content is seldom desirable for the typical applications in the ceramic arts. Regardless of the actual amount of gold in the Liquid Bright Gold solution, the Liquid Bright Gold finished product is usually rated as being 18 karat up to 22 karat gold in purity. Karat is the system of rating the purity of gold, with 24 karat being considered pure gold and any lesser value (such as 18 or 22 karat) containing other metals to dilute the gold content. Regardless of the actual gold content, any purity level (other than 24 karat) will vary in color depending upon the composition of the other metals added to the gold. In fact, the actual karat rating of the product is relatively meaningless (except to the egotistical glory hounds) relative to the final color of the product.

All of Duncan's metallic overglazes are packed in 2 gram glass vials.

The vial is shown nearly to scale at 100 pixels tall.  One 2 gram vial is nearly enough Fired Gold to completely cover a 12" tall vase or similar art object.

    Duncan's Mother-of-Pearl is a translucent luster that provides iridescence to the glazed surface. Try the Duncan Mother of Pearl over any overglaze compatible colored glaze, even black or crystal glazes, for additional interesting effects.  Duncan's Mother-of-Pearl (MOP) is packaged in ½ ounce bottles, one bottle should be sufficient to cover 12 or so 12" tall vases or other art objects.

Vase Decorated with Fired Bright Gold
Overglaze Product Usage Information at bottom of this page.

Overglaze Discount Schedule:

Overglazes are Duncan Color Products with the following Description prefixes: OA OG.

Case pricing applies to 12 units of a single OG/OA item number.

12 Case pricing applies to 12 cases (144 units) of a single OG/OA item number.

Overglazes (OG/OA) may not be combined with other Duncan Color Products to achieve larger discounts.

Product Warnings:

US DOT Warning:  Duncan Overglazes may not be shipped via Air. 

						2 gram	½ oz
Caution Label			OG901		Essence (Brush Cleaner)		$6.00
Caution Label			OG801		Bright Gold	$22.95
Caution Label			OG802		White Gold	$22.95
Caution Label			OG805		Premium Gold	$31.95
Caution Label			OG803		Mother-of-Pearl		$6.00

 Products listed and prices are valid until at least May 31, 2010.

February 27, 2009

Duncan Overglazes Have a New Look!  

    The labels on OG 801 Bright Gold, OG 802 White Gold, OG 805 Premium Gold, OG 803 Mother-of-Pearl and OA 901 Essence have been updated! These labels are compliant in both the United States and Canada, eliminating OG 803C and OA 901C. You will soon start to see the exciting new labels (above) on all overglazes and overglaze accessories.  The outside of the label contains all necessary warnings, and peels back to reveal the inside of the label, which contains the product directions.

Product Reformulation

    In addition to their new appearance, OG 801 Bright Gold, OG 802 White Gold, and OG 805 Premium Gold have been reformulated for improved performance! The product flows beautifully from the brush, and the fired color finish is better than ever! The improved consistency also allows you to get more use from the 2 gram bottle. The unfired color of the product has also changed slightly:

Unfired OG 801 Bright Gold is now brown (was red)
Unfired OG 802 White Gold remains green
Unfired OG 805 Premium Gold is now red (was brown)

    No formula changes have been made to OG 803 Mother-of-Pearl or OA 901 Essence.

    While the reformulated product is introduced into the marketplace the old formula product will continue to exist.  Dogwood Ceramic Supply will continue to have mixed (old and new) inventory while this warning is posted.

Overglaze Information

     Overglazes can only be applied to glazes that are marked overglaze compatible. Some colored glazes are not compatible for usage with Overglazes and will be appropriately labeled. The ware (and glaze) needs to be fired prior to the application of the Overglazes.

The following information is courtesy of Duncan Enterprises:

 
Learning About Mother of Pearl

Basic Instructions:
1. Be sure that the surface of your piece is free of dust, skin oils and lotions to ensure proper adhesion. Wipe surfaces with rubbing alcohol prior to applying the overglaze (except when used over crackle glazes.).
2. Always apply with a brush that is designated solely for use with Mother of Pearl to prevent contamination.
3. Do not stir or shake glaze.
4. Place a small amount of overglaze on a glazed palette.
5. For a swirled look, swirl on 1 coat, overlapping strokes.
6. For a smooth look, brush on all strokes in the same direction.
7. Correct application should produce a light blue tint.
8. Clean brush in Essence and let dry.
9. Overglazed ware can be fired while it is still wet. The kiln must be clean, well-ventilated (do not overload) and follow a normal firing schedule. Do not touch wet decoration and handle as little as possible until ware is fired to avoid smudging.
10. Stilt and fire Mother of Pearl to shelf cone 020.
 
Tips & Techniques:
1. The appearance of Mother of Pearl will vary with the type of glaze over which it is applied. When applied over a gloss glaze, Mother of Pearl will add a shiny luster. When applied over a matte glaze, Mother of Pearl will add a dull luster.
2. If Mother of Pearl is accidentally applied on the wrong area, dip a cotton swab in Essence and wipe off misplaced color.
3. If any areas are missed, go back and touch up before Mother of Pearl dries.
4. If using a metallic overglaze and Mother of Pearl on the same piece, apply and fire the metallic overglaze first.
 
Health & Safety:
1. Overglazes contain solvents and should be used in a well-ventilated area. Those susceptible to odors (such as pregnant women) should be especially careful to work only in areas with an adequate ventilation system. During firing, odors are not dangerous but can be offensive. These odors quickly leave the area; however, you should not work in the kiln area during firing.
2. Duncan Overglazes can be used on surfaces that come into contact with food and drink. Care must be taken to avoid hard scrubbing when washing overglazed ware, because of the possibility of scraping off the thin layer of metal or luster. Treat your overglazed pieces as you would fine china. Although overglazed ware will take repeated washings in a dishwasher, the overglaze will eventually wear away.
 
 
 
 

Learning About Bright Gold, White Gold and Premium Gold

 
Basic Instructions
1. Be sure that the surface of your piece is free of dust, skin oils and lotions to ensure proper adhesion. Wipe surfaces with rubbing alcohol prior to applying the overglaze (except when used over crackle glazes.).
2. Always apply with a brush that is designated solely for use with Bright Gold to prevent contamination.
3. Do not stir or shake glaze.
4. Place a small amount of overglaze on a glazed palette. Apply one smooth coat. Do not let Bright Gold pool in an area; brush it out smoothly.
5. Correct application should produce a flag red tint.
6. Stilt and fire Bright Gold to shelf cone 019-018.
7. Clean brush in Essence and let dry.
8. Overglazed ware can be fired while it is still wet. The kiln must be clean, well-ventilated (do not overload) and follow a normal firing schedule. Do not touch wet decoration and handle as little as possible until ware is fired to avoid smudging.
 
Tips & Techniques
1. The appearance of Bright Gold will vary with the type of glaze over which it is applied. When applied over a gloss glaze, Bright Gold will be shiny. When applied over a matte glaze, Bright Gold will be dull.
2. If Bright Gold is accidentally applied on the wrong area, dip a cotton swab in Essence and wipe off misplaced color.
3. If any areas are missed, go back and touch up before Bright Gold dries.
4. If using a metallic overglaze and Mother of Pearl on the same piece, apply and fire the metallic overglaze first.
5. For solid coverage with Bright Gold, apply over a yellow glaze or a yellow underglaze covered by clear glaze.
 
Health & Safety
1. Overglazes contain solvents and should be used in a well-ventilated area. Those susceptible to odors (such as pregnant women) should be especially careful to work only in areas with an adequate ventilation system. During firing, odors are not dangerous but can be offensive. These odors quickly leave the area; however, you should not work in the kiln area during firing.
2. Duncan Overglazes can be used on surfaces that come into contact with food and drink. Care must be taken to avoid hard scrubbing when washing overglazed ware, because of the possibility of scraping off the thin layer of metal or luster. Treat your overglazed pieces as you would fine china. Although overglazed ware will take repeated washings in a dishwasher, the overglaze will eventually wear away.
3. Caution. Do not place pieces with metallic overglazes into a microwave oven. As with any metallic surface, they could cause sparks.
 
 
 

Learning About Essence

Basic Instructions
1. Swish overglaze brush in solvent until bristles are free of product. Wipe on paper towel.
 
Tips & Techniques
1. Use a separate bottle of Essence for each overglaze product. Mark the bottles according to which overglaze product was used. Contamination can result if brushes and/or Essence used with one product come in contact with brushes and/or Essence used with another. For example, if you use Bright Gold and clean your brush in one bottle of Essence, then clean a brush used with Mother of Pearl in that same bottle of Essence, contamination will result and compromise all subsequent firings.
 
Health & Safety
1. Caution. Flammable. Harmful or fatal if swallowed. Vapor may irritate eyes, skin, and mucous membranes. Contains organic solvents. If swallowed, call a physician. Use in well-ventilated area. Keep out of reach of children.
 
 

Additional Information:

    Looking for Hanovia Fired Gold and other Hanovia Overglaze Products?
 
Liquid Bright Metallics
Liquid Bright Gold, also known as N Gold
Liquid Bright Gold, also known as A Gold
Liquid Bright Platinum
Luster Colors
Mother of Pearl

    Hanovia was a division of Engelhard and when Engelhard was purchased by BASF the Hanovia division was closed. Obviously Dogwood Ceramic Supply recommends Duncan's line of overglazes including Duncan Liquid Bright Gold and Mother-of-Pearl Overglaze found on this webpage.
 

Duncan Color Catalog

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