Seeing how the first beaver panel fits in the kiln, cutting it close for height with only 5/16″ between it and the lid but it will work. A second one- red- will go in when it’s drier. I had to stack a couple of shelf supports behind this first one so that if it tends to want to lean backwards it will be stopped by them, the second panel will need the same behind it.
I think next Friday I’ll turn it on. I modified the firing program just a little by adding another hour of pre-heating @195º making it 9 hours so these are good and dry for sure. I also added 5 minutes at the end making it hold at 2,060º for 15 minutes. So overall it will take about 25 hours for the firing process and then “overnight” for cooling down.
What most people know is water boils to steam @ 212º and is gone, but what they don’t know is the chemically bound water in apparently bone dry clay stays in the clay up to at least 700º before it finally burns out.
I could use a larger kiln like the Olympic oval model which would be large enough to lay pieces like these flat, but besides the cost being dramatically higher than this one was, I’d have to upgrade my home power line from the weatherhead on in, the 100amp breaker box and incoming line isn’t enough capacity.
The first pressed clay is now out of the mold and she came out with a very minimal amount of surface defects that have to be fixed by hand. In the 1890s when these pieces were made the workers pounded the clay in using a small sand bag to ram the clay into the details and eliminate the little “creases” that I seem to get between pieces of clay laid in and pressed next to each other. Might help too if the clay was a little more moist and softer but I hesitate to add water since more water causes more shrinkage. To get a batch custom mixed to add a little more water I’d have to buy I believe a full ton and there’s an extra charge too.
Really want to see this in the red clay but I don’t have enough to do it and only had 50# of this white clay left.
And now 3 days later she is firmed up but not dry, so she can sit like this for about 2-3 weeks to dry before firing.
I decided to take the steps needed to be able to produce this little keystone in kiln fired terra cotta, now after several steps- the final step is pictured, I have the plaster piece-mold to do it once it dries out.
Now I have the very first hand-pressed clay from the new plaster mold out and drying, it took 50# of clay to press the design, and about 10# of that was removed during the final work on it.
Now it will set loosely under plastic to slowly, evenly dry out over the next week to 10 days, it will need to be 100% dry before it can be fired in the kiln. I plan to press a second one either in the same white clay, or the red clay.
The photos show the progression from start to finish, with the back of the sculpture being made exactly the same way the antique original 19th century architectural ornaments were made, not really required for my pieces, but mostly it’s done out of tradition and authenticity.
I also did one in the red clay today;
The first cast in the dirty bronze finish
Now I have this cast finished with the weathered terracotta finish.
The first cast with no finish applied to it yet
The template for the lion is done except for attaching the one side piece once I decided how wide the sculpture was going to be, after coming home and measuring the lions head and found it was 9″ wide, I decided on 11″ wide for the backing block, so just like they did the old plaster ceiling moldings this box and template is used the same way but on clay.
I have the 1st section of the little mold made, after it hardens I can mold on the next section, it will take 3, maybe 4 pieces.
Mold started of my lion mask
The mold is done and I made a cast in it to see how it looks, it can be used with the clay backer formed and shaped with the template I made earlier.
Now I can take this and incorporate him into the new clay backer and while the plaster cast is still wet make a mold of the whole thing since the rubber I use is unaffected by moisture in the model.
This would have to be done on the moist clay once formed since clay shrinks as it dries and plaster does not.
I went ahead and shaped the clay backing block for the lion with the template box and just set the lion in it’s approximate position for the photos and then sealed it up in a plastic bag to keep it from drying too much too quickly, once the clay sort of firms up I can remove the sides of the box and finish and tool texture the 4 sides and the face nicely, and then look at setting the lion in and filling the gaps around the sides of it.
Since I have most of the 2 gallon kit of mold rubber left over that needs to be used up, I decided to set up this clay model I did in 2008 after an original polychromed terracotta at the 14th st subway station in Manhattan. A volunteer back then took several photos and obtained measurements for me to work with. The model has been kicking around in the studio, the basement and elsewhere around the house while I decided on how I wanted to do the molds.
Originally I was going to do 2 molds, as a one-piece panel, and as thinner tiles in terracotta. For now I’m going to caulk-in the seams to have it as a one-piece panel with the seams looking like mortar joints.
Setting up the model for the mold involves cutting a sheet of drywall in one piece to surround the assembly so I can raise/lower the drywall to get the final depth of what I want for the resulting castings’ thickness.
I wanted to keep as thin as practical to lessen the weight, but the lower tail fin section was thinner than I felt it should be, so I lowered the drywall down 1/2″ from where I originally thought it might go, that leaves the thinnest portion 1-1/2″ thick.
I started caulking in the seams between pieces to fill, but not obliterate them- so the liquid mold rubber can’t drizzle down through the spaces before it sets up.
Only the rubber portion will be done for now, the plaster support shell for this and the plaster mold for the beaver will have to wait until I order some of my casting material, molding plaster, and a few boxes of clay if they clay I have on hand is not usable (been sitting around for a couple of years it still dries out even in the unopened plastic bags)
It might be a month before I order that stuff since I still have 3 bags of casting material on hand and it all has to be freight shipped, so it’s about a $600 outlay for what I’ll want to order.
One of the original polychromed terracotta eagles at the 14th St platform.
Started on the positive mold of my beaver sculpture by bringing the negative mold up from the basement and applying the release agent to it, after I have dinner I’ll be applying the rubber compound.
The mold in progress, and just after the 2nd application of rubber started to gel I poured the warm plaster in for the support shell. The heat from the setting plaster will help cure the rubber faster too. To-morrow I can take the negative mold apart and peel that rubber off the new and I’ll have a rubber positive with this plaster support inside it.
After filling the cavity with plaster for support
And here’s the rubber positive to use for making the plaster piece-mold to press terracotta in.
The other pair of French carvings I bought arrived in a 17# package, wow, these are nicer in hand than the seller’s photos! Whomever carved these was extremely good! These have a lot of extra detailing and undercutting which took more time than just scroll cutting the shape, the undercutting can be seen especially in the 2nd photo which shows the top of the wings closer, that cavity was carved down giving the wings a thinner, more natural appearance with that “V” cut in.
They have some old wood shrinkage cracks in them but the patina and finish are so nice I think I’m going to leave them exactly as they are, maybe just secure the one loose base molding. Last purchase for a while I guess! Carved oak, 13-1/2″ x 14-1/2″ x 4″ deep. Ca 1890s France.
I’m thinking of making a mold of them, a pair of these cast in something like a wood filled resin would sell as bookends with a little modification or addition for the base to give them stability.
These are really nice and positioned as they are in the 2nd photo they would look fantastic as bookends!
These are coming from a dealer in Oregon I purchased from before, I think he buys a lot of furnishings and antiques in France and Europe and ships a container full to Oregon which costs a lot less for the international shipping when the cost is spread out over a whole container full of items.