Decorating The Portable Ceramic Heater for Efficiency
Getting Started with Your Basic Fform.
Now that the basic form has been constructed and allowed to dry a little, you now need to consider how you will decorate it. Decoration here means, to increase heat transfer and this can be done by increasing the surface area. You can do this with slab rolled fins or coils. You will need some slip and tools to fix the decorations to the basic form. There are several thing to be done starting with your basic form. These include;
- Separating the top part from the base plate.
- Trimming the top and the base
- Rough cutting the breather notches and/or hole
- Smoothing and rounding all sharp edges
- Making and adding your decor, functional and decorative
First, take your leather hard piece (achieved by partly and carefully drying the work) and fasten it, right side up as originally thrown to the wheel head using fresh, plastic clay. Make sure the whole project is centered. Once that is done, and the wheel is turning slowly in a counterclockwise direction, take your pin tool and begin inscribing in order to separate the one piece into two. Be careful with the speed to prevent the top from flying off uncontrollably once fully cut off from the bottom plate.
Once you have two pieces, you can work on them separately. Remove the bottom plate. Take the top and turn it upside down. You will need to center the work (upside down) by constantly tweaking and adjusting the clay clamps. Once this is done, get the wheel in counterclockwise motion and using a carving tool, start removing excess material from the inside until you have a clay wall even from top to bottom. Remove the piece that is trimmed and replace it with the bottom plate. This will need to be trimmed on both sides. Place, center and fasten the plate upside down and carefully trim the bottom complete with a foot rim. Once this is done, flip it over and cut the inside so that you have a flat, level bottom with a raised rim upon which the top part will rest. Once that is accomplished, you can begin cutting breather notches.
Cross Sections of the Two Pieces as Finished
Once you have thrown and trimmed the heater pieces, you want to now cut the breather notches There are a number of ways to do this. Once can use a pin tool to rough in the notches. After this, you will need to use a carving tool to smooth the rough edges. Further smoothing is accomplished by using a wet shammy to round off and smooth away all sharp and rough edges.
Below is a video the describes incising. There are other methods, such as fusing thin coils and slabs to the surface of the heater. Use your creativity and tranferable skills from other forming methods as a guide.
After Carefully Drying Your Pieces
The final step in preparation for firing is to sand off all rough pieces missed in your handling and decorating. This is also a good time to inspect for cracks. Considering the nature of the piece, crack(s) are most likely where separate pieces were joined. Hopefully, there are none, but if there is, then you may have to do some repair. To do this, you need white vinegar and powdered clay, likely from what you sanded off your pieces. Mix the dry powdered clay with a very small amount of vinegar. You should end up with a thick slip. Also use some vinegar directly on the crack(s) you are repairing. Scribe a little with a pin tool and then apply the slip, working it into the crack(s). Let dry and reinspect for crack(s). Once you are satisfied with your work, let stand in a dry place in preparation for firing.
Always handle the dried pieces with extreme care. If anything falls off, you may need to attempt another repair, but there is a limit as to how far you can push repairs. In the end, it is best to make a number of pieces. Next in this series if firing protocol and considerations as to what works and what does not.
Fixing Cracks in Greenware Ceramics
Other Considerations in Working with Ceramics
- Important Considerations in Ceramic Construction
Working with ceramics is a complex art and science. If you are considering integrating other non-ceramic materials, there are some important things you need to know and respond to.