Important questions and answers about adhesive for gold leaf (milk for application or gliding milk)
What is gilding milk?
The term "gliding milk" or "application milk" refers to a special glue and an application agent used in the gilding of objects as well as works of art. The application milk serves as a primer and requires a drying time. There are various application agents, which are explained in detail below.
The company Kölner Vergolderprodukte GmbH has been offering various application agents for different areas of application since 1979. The Permacoll, Instacoll and Aqua Size gilding agents are particularly popular for gilding objects indoors and outdoors.
What is Kölner Instacoll?
Instacoll from Kölner is an acrylic mixture and a special bonding agent that is suitable for gilding with gold leaf indoors and outdoors. The Instacoll system from Kölner consists of two main components: The laying agent (base layer) and an activator. In the first step, the base coat is applied to the surface and left to dry for one hour. After drying, gilding can be applied for one hour. If gilding is to be continued at a later stage, the activator can be used to reactivate the base layer for adhesive bonding. It is worth noting that activation can be carried out even years after the base coat has been applied, and gold leaf can be applied just a few minutes after activation.
What is Kölner Permacoll?
Kölner Permacoll is a permanent adhesive without activator, suitable for interior use and acrylic-based. In contrast to Instacoll, Permacoll has increased adhesive strength and is therefore very suitable for bright gilding with impact metal. Gilding Permacoll with gold leaf is also possible. Surfaces that are outdoors, exposed to weathering or mechanical stresses should be gilded with Instacoll instead.
Application of the gold leaf adhesive
How long does the gold leaf adhesive have to dry?
The time required for drying always depends on the application agent used. Instacoll dries within one hour and can then be used for applying gold leaf for another hour if it is used for gilding trim or letters.
Permacoll, on the other hand, requires a shorter drying time. About 15-30 minutes after Permacoll is applied, the surface is ready to accept the impact metal or gold leaf.
For both Instacoll and Permacoll, drying time is affected by ambient temperature and humidity. The times given here refer to a temperature of 15-20 degrees and a humidity of 50%-80%.
If you want to check whether the gold leaf has dried, the following procedure is recommended: In the gold leaf booklet you will find tissue paper between the gold leaf sheets. Take a piece of the paper and now press it carefully onto the layer that you have treated with the lay-on agent. The tissue paper will not stick when the layer is dry.
How does gilding with lay-on material work?
In the Instacoll system, the first step is to apply the Instacoll base coat with a flat brush on the surface to be gilded. After the base coat has dried for 60 minutes, the Instacoll activator is spread on the surface using the Instacoll Tissue and left to dry for 5-10 minutes. The gilding can then begin. This should be completed after one hour at the latest, as the adhesive strength of the base layer and the activator decreases after this time window. If it is a matter of gilding letters or decorative trim, it is not absolutely necessary to use an activator.
Gilding with Permacoll proceeds without the use of an activator. After the drying time of 15-30 minutes, the gold leaf or impact metal is applied directly.
What is the substitute for application milk?
In some cases, the gold leaf is applied to the surface with a special oil mixture. However, there are some advantages that the Instacoll system has over a conventional mixtion.
What are the advantages of the Instacoll system over oil mixing?
- While the time required for gilding with an oil mixture is limited, with the Instacoll system, with the help of the activator, gilding can be carried out indefinitely.
- After applying the oil mixture, it takes between 3-12 hours before the actual gilding can be started. With Instacoll, this period is limited to only 1-2 hours.
- Weather resistance occurs only after several weeks with the oilmixture, while with Instacoll weather resistance occurs after the gold leaf is absorbed (provided there are no extreme weather conditions).
Can I apply gold leaf without a lay-on agent?
Gold leaf should not be applied to the surface without a lay-up agent. A lay-on agent is always needed for a secure hold.
Cost & purchase of gold leaf application agent
Where can I buy a lay-on agent?
Instacoll, Permacoll, as well as other lay-up agents can be purchased directly here in the store at Gerstendörfer Blattgold.
What do I have to consider when buying a mounting compound?
When choosing the application agent, it is important to consider whether the agent is to be used indoors or outdoors. In addition, the choice of the gilding agent should always be based on the material that will be used for gilding. In the explanation of Instacoll and Permacoll, you will learn when which application agent is suitable for you.
What is the price of a gilding agent?
The prices for lay-up materials always depend on the quantity and the type of lay-up material. In the product overview, you can find out the current prices for Kölner's slip-on agents.