Composition ornament
Encyclopedia
'Compo
' is a mouldable resin worked either by hand or more usually pressed into moulds to produce decorative work. It's now most commonly seen as part of gilded
picture frames, but was in use for many smaller decorative mouldings from the later part of the Baroque
period.
Take 250 grammes cabinetmakers' pearl glue and soak in adequate cold water for several hours. Drain the excess water, then heat in a double boiler or electric gluepot to 70°C until liquid. Add 20 mls of glycerine and 10 grammes of zinc oxide
.
Powder 100gms of rosin
(colophony) and heat in a small pan. Beware of fire! The rosin should melt at around 90°C. Add 20 mls Venice turpentine and 60mls linseed oil
, and mix well. Mix the melted rosin etc. into the hot glue and stir well.
The compo itself can now be made by pouring the combined contents above onto 600-700 grammes of whiting
in a bowl. Stir the initial hot mixture with a wooden spoon.
Rub talcum powder on your hands (to prevent sticking), then work the mixture by hand until it has the consistency of glazing putty.
Work the compo into conveniently-sized flat cakes, then wrap them well in kitchen cling-film (Saran wrap). Compo
will keep in a freezer for a month. Defrost the compo completely before placing it in a bain marie to soften it ready for moulding.
The recipe proportions aren't rigid. The pearl glue can be increased to 300 grammes for a harder and stronger result, or then the rosin to 150 grammes for a more elastic and generally more robust composition. Some workers prefer to use rabbit-skin glue
(as used in bookbinding
) rather than pearl or hide glue, giving a more flexible result.
Some understanding of what each ingredient is doing helps when adjusting the basic recipe:
Compo
Compo may refer to:*A slang word in the demoscene for "competition".*A character from the British TV series Last of the Summer Wine named Compo Simmonite, played by Bill Owen.*British army field rations....
' is a mouldable resin worked either by hand or more usually pressed into moulds to produce decorative work. It's now most commonly seen as part of gilded
Gilding
The term gilding covers a number of decorative techniques for applying fine gold leaf or powder to solid surfaces such as wood, stone, or metal to give a thin coating of gold. A gilded object is described as "gilt"...
picture frames, but was in use for many smaller decorative mouldings from the later part of the Baroque
Baroque
The Baroque is a period and the style that used exaggerated motion and clear, easily interpreted detail to produce drama, tension, exuberance, and grandeur in sculpture, painting, literature, dance, and music...
period.
A Compo recipe
A basic compo recipe, which can have many variations.Take 250 grammes cabinetmakers' pearl glue and soak in adequate cold water for several hours. Drain the excess water, then heat in a double boiler or electric gluepot to 70°C until liquid. Add 20 mls of glycerine and 10 grammes of zinc oxide
Zinc oxide
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
.
Powder 100gms of rosin
Rosin
.Rosin, also called colophony or Greek pitch , is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black...
(colophony) and heat in a small pan. Beware of fire! The rosin should melt at around 90°C. Add 20 mls Venice turpentine and 60mls linseed oil
Linseed oil
Linseed oil, also known as flaxseed oil, is a clear to yellowish oil obtained from the dried ripe seeds of the flax plant . The oil is obtained by cold pressing, sometimes followed by solvent extraction...
, and mix well. Mix the melted rosin etc. into the hot glue and stir well.
The compo itself can now be made by pouring the combined contents above onto 600-700 grammes of whiting
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
in a bowl. Stir the initial hot mixture with a wooden spoon.
Rub talcum powder on your hands (to prevent sticking), then work the mixture by hand until it has the consistency of glazing putty.
Work the compo into conveniently-sized flat cakes, then wrap them well in kitchen cling-film (Saran wrap). Compo
Compo
Compo may refer to:*A slang word in the demoscene for "competition".*A character from the British TV series Last of the Summer Wine named Compo Simmonite, played by Bill Owen.*British army field rations....
will keep in a freezer for a month. Defrost the compo completely before placing it in a bain marie to soften it ready for moulding.
The recipe proportions aren't rigid. The pearl glue can be increased to 300 grammes for a harder and stronger result, or then the rosin to 150 grammes for a more elastic and generally more robust composition. Some workers prefer to use rabbit-skin glue
Rabbit-skin glue
Rabbit-skin glue is a sizing that also acts as an adhesive. It is essentially refined rabbit collagen, and was originally used as an ingredient in traditional gesso.-History:...
(as used in bookbinding
Bookbinding
Bookbinding is the process of physically assembling a book from a number of folded or unfolded sheets of paper or other material. It usually involves attaching covers to the resulting text-block.-Origins of the book:...
) rather than pearl or hide glue, giving a more flexible result.
Some understanding of what each ingredient is doing helps when adjusting the basic recipe:
- WhitingCalcium carbonateCalcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
gives body.
- Pearl glue acts as a binder.
- Linseed oilLinseed oilLinseed oil, also known as flaxseed oil, is a clear to yellowish oil obtained from the dried ripe seeds of the flax plant . The oil is obtained by cold pressing, sometimes followed by solvent extraction...
makes the mixture soft.
- RosinRosin.Rosin, also called colophony or Greek pitch , is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black...
makes the mixture elastic.
- Venice turpentine prevents cracking.
- Glycerine tempers the glue.
- Zinc oxideZinc oxideZinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
prevents formation of mould.