Published Sep 28, 2015
I have heard of sledging before and am sad to say that I've never tried it. Sledging is essentially extruding plaster to create finished objects or molds. Plaster is one of those things where you either love it or you hate it. I love it, but don't have a space in my studio to use it, and this technique is making me want to make a dedicated plaster area! I'll add that to my ever expanding list of things to do and techniques to try.
In today's post, Anthony Quinn shares what sledging is and how to easily profile plaster to create unique forms. If you love plaster, this could be a new process to add to your practice. If you don't, well, maybe this technique might change your mind! Happy mold-making! – Ash Neukamm, assistant editor
Sledging, or profiling, is a modeling technique with huge potential. Sledging describes the act of dragging a profile through wet plaster and is, essentially, extruding with plaster. Success lies in the simplicity of sledging, which relies on the preparation of templates and tools that allow you to form the plaster with comparative ease. An understanding of the properties of the plaster is vital for this technique.
The template acts as a guide for the profile. Clay is used as a wall (or cottle) around the template into which plaster is poured. The trick with the plaster is to catch it at the right point in tis setting time. Pull the clay wall down when the plaster is cheese soft and will support its own weight. Working with urgency, as you do not want the plaster to get too hard, first use a scraper to trim the plaster back to the template. Then pull the profile through the plaster; repeat this until the profile touches the template.
Stick the template you have made to a smooth board or sheet of glass. Place this board onto a wheel, securing with clay. Build a strong clay wall around the template (1). This is called a "cottle."
Mix a generous amount of plaster. Then, early in the process of mixing, decant a small amount of the plaster into a separate vessel. When the plaster is ready, pour it into the clay "cottle' you have just built (2).
After a few minutes, when the plaster is "cheese soft" and will support its own weight, carefully remove the walls of the cottle (3), and using a scraper, clean away the plaster until it is square to the template underneath it.
Acting with urgency, and holding your profile perpendicular to the template, press gently into the plaster and rotate the wheel so the tool cuts away the plaster (4). Repeat this process, cutting away any excess plaster until the profile touches the template.
When all the excess has been removed use the profile to secure the overall shape (5). You may need to drizzle some water over the model to ease the passage of the profile and smooth the surface.
Take the plaster you decanted earlier and slowly drizzle it over the surface. Pull your profile over this mix and the plaster hump (6). This will help create a smooth surface and repair any blemishes or nicks.
As you develop your skills and confidence in this area then the potential of sledging will really come alive. Once mastered there really is nothing that can't be made using this process.
Sledging is a very old technique; it was used for the extruding of long lengths of architectural detailing, such as cornicing. It is said to be called sledging because in the workshops where these pieces of cornicing were made they would pour a great quantity of plaster in front of the huge profile. Two or three men were needed to push the tool, and the youngest apprentice would be required to sit on top of it to weigh it down, looking like he was riding on a sledge through the snow.