We’ve never seen a project like this before – Sarah Manchester is making some very large paper mache ceiling tiles for her home, and she agreed to show us how she’s doing it.
I’m really impressed with the amount of detail she’s able to achieve with her beautiful design – she’s capturing every shape of the original clay sculpture. In fact, her advice for using paper pulp in a plaster of Paris mould could be used for all sorts of projects. Thank you, Sarah, for sharing this project with us!
I’ll let her take it from here …
How to make paper mache ceiling tiles in a plaster mould.
©2017 Sarah Manchester
This is the first time I’ve worked with PM but it won’t be the last! I have previously cast in plaster and cement. Once this project is finished I have several more in mind. Smaller though.
The ceiling panel project came about from a desire to make my kitchen ceiling more interesting. I have decorated the kitchen in a Victorian/Gothic style with hand painted ‘Pugin’ tiles and Gothic cupboard doors. I love looking at ornate period plaster ceilings and thought I’d try to create one of my own.
During my research, I discovered 17th century ornate ceilings were actually made of Papier Maché and not plaster, which became widely used later. I have never used PM before and found Jonni’s wonderful website full of useful information. I determined to have a go.
I wanted the panels to be as light as possible to make installation easier. I have installed large plaster ceiling roses and cornicing in the house before but it is very tricky and heavy work. A whole ceiling would be a nightmare to do and the weight would be excessive. PM seemed like the obvious choice.
I began by modelling the first quarter in clay. This part was to be repeated four times so to make the process quicker and to avoid modelling the same pattern over and over, I made a plaster mould and pressed clay into it to create the remaining three quarters. Left overnight, each piece could be removed easily from the mould without too much damage. Here is the piece ready to have plaster poured over to make the mould.
I continued modelling the rest of the panel having carefully drawn the outline of the quatrefoil on a plastic sheet to make sure the overall shape was correct. The whole thing is 30 inches square.
I repeated the mould making process with a cardbord and clay wall around the outside, plaster poured in, and because it was so large, I reinforced the top by adding wooden batons. This made it possible to turn over when the plaster had set, without the risk of it breaking. Set plaster is still soft and fragile until completely dry, which can take days or weeks.
I removed the centre seed pod piece , cut it in half and made a separate mould of it to save on the amount of plaster needed. Once the mould had been turned over, I removed all the clay and washed the mould to remove any clay residue. I left the mould to dry for a couple of weeks before sealing it with several coats of shellac.
In the time the mould was drying, I set about making the paper pulp. I used everything that came through the door. Cardboard boxes, newspapers, glossy magazines, envelopes, office waste paper and egg boxes. I tore everything into pieces and filled a large plastic dustbin. I added cold tap water and left for a couple of days before using an electric drill with a mortar mixing attachment to reduce it to a pulp.
I couldn’t decide whether to use the pulp plain or with glue added. I was concerned the glue would make it difficult to remove from the mould. I had read instructions about using a layer of unglued, damp paper first when using paper strip layers in a mould to make removal easier and had come across plain pulp being used to fill a mould solid, using a sponge to remove excess water. Eventually, I decided to go ahead with plain pulp. I processed the pulp a large jugful at a time using a stick blender and squeezing out as much water as possible through old tights, using up each batch before making another. That way the remaining pulp stayed in the large bin further breaking down in the water and not requiring extra storage space. I must say, after three weeks, it started to smell a bit strange so I added a little floral disinfectant to remedy this.
I greased the mould with petroleum jelly. I had read instructions to use as little as possible as the residue can make it difficult to paint afterwards, so I just brushed and smeared as thin a layer as I could. I was satisfied that I had covered every nook and cranny and started to press the pulp in. It took me a whole week, pressing pulp in a thin layer as hard as I could in order to make the finish as smooth as possible. I used a flat wooden tool to help do this. I added three layers of glued paper to the centre because it seemed too large an area to just use pulp. I glued sheets of newspaper over the top to form the backing to the panel.
After several days, the pulp was dry and I tried to remove it from the mould. It was almost a complete disaster. The pulp has stuck in many places making it impossible to remove without breaking up.
The small areas that did come out, I was pleased with. The pulp had taken on the intricate detail very well and was quite smooth. The only area that came out easily and didn’t break up, was the centre. This was no doubt thanks to the reinforcing layers of paper and glue. I was disappointed that all my hard work had ended up in pieces, but I was pleased with the little successes and I had learned a very valuable lesson.
I started again …
This time, I slathered the petroleum jelly on as thickly as I could. I made the pulp mix a little wetter so that it went on a little easier and quicker. This was after a bit of experimentation using the small mould. I had achieved success.
The extra water and petroleum jelly enabled the piece to shrink away from the mould, better enabling release. I also cast the sections separately. I put bits of clingfilm between areas that joined and the whole thing was reinforced with three layers of paper strips and glue. Here is the piece in progress.
I made the layered backing separately and as I removed the pieces from the mould, glued them onto the backing. The outside quatrefoil, each of the four quarters and the centre were all removed separately with very little damage. To ensure a good stick, I weighted the pieces with tins and jars full of water as they were drying onto the backing .
I repaired the damage using pulp with glue added which makes it easier to shape and decorator’s filler for the cracks, then gave it a coat of ordinary emulsion paint to seal it and fill any hairline cracks. I am using up leftover paint from previous decorating projects.
If I was only making one or two of these panels, to use as centrepieces on the ceiling, I might have been tempted to use filler and sand to a really smooth finish. As I am using them all over the ceiling and making approximately 20, I didn’t think this was practical. I am pleased with the quality of the finish as it is for my purposes.
I used acrylic paints for the final coat, including the metallic golds. The paint went on without any problems regarding any petroleum jelly residue. I tested acrylic colours on the original broken panel pieces without the emulsion coat and they went over the residue without problems too.
Here is the painting in progress.
Once the panel was painted, I trimmed the excess paper from around the edges, glued the backing and installed it on the ceiling using screws through the pulp into the plaster ceiling. I put a bead of decorator’s filler around the outside edge to achieve a smooth join with the ceiling and supported it overnight.
As you can see, I’ve positioned it so that it will take two panels to frame the ceiling light centre. That way, I didn’t lose the beautiful panel centre which would have had to be cut away to position it centrally around the ceiling light. The areas of the ceiling showing between the circles when the panels are fitted touching each other will be covered in layered newspaper cut to shape and painted. I will post a picture of this when the next panel is up.
I hope you have enjoyed my post. I welcome any questions and comments.