Grain Filling with Plaster of Paris,
Oiling In,
Fadding or Skinning In

Filling — A glass finish can be achieved on fine-grained woods such as walnut without the need for filling, but woods such as rosewood, and particularly the Rio rosewood, have very deep and often long pores that need to be filled with something other than polish if the work is to be done economically in a reasonable time. No filler will completely fill the pores requiring no additional filling from the shellac of the polish, but the use of a primary filler reduces the time and the expense in polish required. The four steps to prepare the work for the bodying processes are 1. Filling in, 2. Oiling in, 3. Fadding or Skinning in and 4. Cutting down.

The polish used in this example is a pale clear polish de-waxed and decoloured in India, named Decol.

The panels illustrated are for the top door of a Kirkman “Vertical Iron Grand”. The original panels had been replaced with plain panels in a nondescript wood, so new panels were made up from a donor piano, a smaller Kirkman of the same age. The inlaid central panel was extended at each end and the matching side panels were cut from the bottom door panel. The whole piano is veneered in a very fine Rio rosewood.

Papering up —Before filling, any necessary stopping is done, the surfaces are papered smooth using 3M 618 “Frecut” paper of P180 grit and dusted.

The Filler —The filler is superfine Plaster of Paris with a small amount of pigment added. For rosewood, equal quantities of Brown Umber and Rose Pink are used. The powders are well mixed.

Applying The Filler —A folded rag is wetted, lightly wrung out and dipped in the powder. This is rubbed over the surface of the wood with the grain, across the grain and with a circular action in order to fill the pores as much as possible. The rag should be wetted just enough to create a thick creamy paste to work into the pores. If it is too wet, dip it in the powder again until the right consistency is obtained. The panels in the second picture show the result when the plaster has set and dried out.

Papering up —Once the filler has set and the moisture has evaporated from the plaster that has been forced into the pores, the excess plaster is papered off to leave the surface smooth, with the plaster showing only in the pores.

Oiling in —The work is next oiled in. Raw linseed oil is wiped over the surface to discolour the plaster filler and to bring out the figure of the wood. The work is then thoroughly rubbed dry with scrim or rags so that no oil remains on the surface. In the small panel against the wall it is possible to see the pinkish colour of the plaster in the pores, but as polish is later drawn down into the pores in the fadding and bodying processes, this will become invisible.

Fadding —The next process is named Fadding or Skinning in. The fad is the uncovered wadding heart of a previously well-used bodying-up rubber, used to apply the initial skin of French polish to the work and further to fill the grain. The fad is always worked in straight lines and without oil. At the beginning the fad should be used fairly dry in order to apply only a trace of polish while at the same time taking up any oil remaining from the oiling in process. After a few passes with the fairly dry fad, more polish can be used in order to build up a substantial skin. When skinning in it is best to work on several pieces at once so that the polish has time to evaporate before the next pass; otherwise the surface will be torn and fibres from the fad will catch in the surface.

One should aim for as even a result as possible but bear in mind that the purpose of skinning in is to fill the pores. Most of the polish applied is destined to be removed, once it is hard, by cutting down, and this will provide a smooth surface ready for the subsequent bodying-in process.

The picture below shows the bottom door parts and the fall of the Kirkman filled and oiled in ready for fadding.