With the new mold finished, here’s the first cast.
Here’s the 3 section plaster master to be worked on for the larger panel once it’s dry.
All 3 sections and the narrow strip need to be assembled together in a nice squared shape and molds made then of it. The narrow strip on the right needs to be trimmed and cleaned up yet.
The new Art Deco model 8B plaster masters are now laid out on a board and being prepared for the mold making process.The gaps on the bottom (at at the top out of view) between the four sections will all need to be filled and then smoothed and the texture blended in so it all forms one cohesive panel.
I just ordered the materials I need for making the 1st mold of this which will enable casting the panels in interior cast-stone and concrete. I will also be making the negative mold from the 1st rubber mold for use in making the plaster piece mold required for pressing terra cotta. Sounds complicated but it all involves making 3 molds!
The 2nd mold with is a rubber positive of the design that looks just like the plaster version only it’s made of rubber is used to easily deal with undercuts and the like when making a rigid plaster piece mold from it,the rubber is soft and flexes and the plaster mold can easily be pulled off it even when there’s undercuts.
That 3rd mold- the plaster mold is the one that will be used to hand-press the clay into, if this wound up selling a lot I would make a 4th mold- of the plaster piece mold so that I can pour new molds as easy as pouring plaster. Without the 4th mold if the 3rd plaster piece mold gets broken or wears out from use, it’s more work and time to make a new one from the second mold.
I managed to find an aluminum version of the top section of one of the big posts pictured in OP of the thread, it has some damage and it’s not complete but it’s something to start with! Maybe I can find some more of the parts for it or a complete one later, for now I can enjoy working on this part of one
There is no mechanism inside but they are fairly easy to find.
This one has a second door on the back but the door doesn’t have that “HP” on it.
This post must have been hit by a car and removed from service due to the damage, the aluminum is bent out of squareness just enough there is a crack below the door and one above the door which doesn’t close properly. I guess I’ll have to learn a little aluminum welding to fix this after trying to straighten it with some clamps diagonally to ease it back to squareness.
I didn’t know any were made from aluminum, must be one of the last made maybe in the late 1930s since they were otherwise made of cast iron in the 1920s, I prefer cast iron but will take what comes along!
According to a look up for the box number it appears it came from around Grammercy Park- Lexington and 21st street, and that there is another one there according to Google street view which must have replaced this.
I now have the modelling finished on this master clay model, once it dries a bit I’ll be going over the surface and cleaning it up more. Once it’s dry the first mold will be made and then I’ll be combining 3 plaster casts of this to make one larger panel shape, then two molds will be made of that- one for casting interior cast-stone and the other for pressing clay for the terracotta version.
Now that the clay is just about right for working with it I did some refining and cleanup on the upper 2/3rds of the model today. I’ll be doing work on the lower 1/3rd tomorrow. The “window” of workability of the clay is fairly short once it reaches this point of firming up, made shorter too by the fact there isn’t a lot of mass in this relatively small model and the humidity in the house is very low. Even wrapped in plastic and kept sprayed periodically with water it still progresses towards dry so I need to finish this up more or less by next weekend.
I hollowed out the back of the model today which will help let the clay start to firm up a bit, I also did a little minor work on it as well.
The sculptor has to work around and with the materials and the “mood” of the materials, clay definitely has a “Mood” that depends on the humidity in the room, how moist the clay is, how thick the clay piece is and what is being made with it.
When the clay is fresh it’s very pliable and soft, it can also be sticky which makes using tools difficult as the clay wants to stick to the tool.
I usually use just fingertips initially for those reasons, then as the clay starts to lose some of the moisture and become firmer and less sticky, then shaping with tools comes in. It’s a process that the clay won’t allow to be rushed, the degree of this also depends on the exact clay being used.
I find this red clay seems to be “stickier” and needs more time to dry to firm up than other clays, but the beauty of this red clay is that it has absolutely no tendency to warp or crack, that’s not to say it can’t or won’t but it’s been my experience with it that it’s been extremely stable, so that aspect tends to override the slight negative of stickiness or having to wait longer for it to firm up.
Here’s a newer photo:
I picked up this ca 1896 gamewell fire alarm box recently at a real steal of a price, it arrived today in fact. The really nice thing is this box is in what I call “un-messed with” condition and has it’s original 100+ years of exposure patina which I intend to retain exactly the way it is other than a little gentle cleanup with soap and water.
the 1st photo shows the cast-iron exterior, the 2nd photo shows the inside door of the cast-iron interior box with the 1896 version of the instructions which use the word “hook” (newer boxes used the word “handle”)
The 3rd photo shows the brass windup mechanism stamped with “The gamewell F.A. telegraph co., NY and the patents 565086 and 548317, the 3rd patent between those two is unreadable due to holes drilled for the gears.
The inner boxes of these were often replaced with newer models as they came out, ditto for the outside doors, so many of these 1896 era boxes have an 1896 era shell and 1920-1930 or later doors and interior box mechanisms. You don’t often find one like this that is about as original as they come, in good condition with all their parts, and have not had some fool mess with them by sandblasting, repainting, and highlighting the lettering with white or gold paint.
The little house shaped deal on the door in the 1st photo is a Cole keyguard, it has a piece of glass and a tiny lock to keep the little door closed (glass needs to be replaced on it) it secures the door key, and to open the door the public was expected to break the glass to open the door. The Cole keyguard was patented in 1906 but was in use before the final patent was granted since it normally takes several years for a petent to be final. Since the lettering on the door accomodates the keyguard, the keyguard was not added on later.
That means the outside door was probably replaced around 1900-1906.
The top of the 1st photo shows the Gamewell logo- a fist holding lightning bolts, the fist position is the clue that proves the approximate date of the box. Prior to about 1896 the former logo had the fist slanted at an angle, that was changed to having the fist vertical.
This dates the shell and the inside box to ca 1896 and the external door to ca 1900-1906 as best as can be determined by all of the evidence.
Going back further in time the “cottage style” boxes were made in the 1870s, but instead of the fist and lightning logo they put the year there, i’ve seen a photo of one with “1878” on it, I don’t believe any of those still exist on any public streets today- they were replaced by this newer style box in the 1880s-1890s through the 1920s, and then Gamewell came out in the late 20s with a newer model made of a patented aluminum alloy called “Herculite.” These still had the “cottage” style shape box, but the inside mechanism and box were changed a bit, and the exterior doors had a completely different look, there was also no more access by the public to the inside with a key, the actuator handle was externally mounted under a spring loaded door instead.
Some time around the 1950s they changed doors and guts again, going cheap with aluminum mechanisms replacing brass, plastics and a plainer design.
I cut out a template tool to use to shape the convex holes on the left strip so they are all the same curvature and size, of course they all need cleaning up and refining but that has to wait for the clay to get firmer as moisture dries out of it. Right now the clay is still very soft and will be until I hollow out the back.
Here’s my clay model just started with the larger scaled design applied to the surface using a ruler, square and compass. The original nickel plated bronze artifact to the left being used to resize the model is from the Women’s House of Detention at 10 Greenwich Ave, NYC which was designed by Sloan and Robertson in 1931.
The connected courthouse was the scene of the notorious Harry K Thaw murder trial of renowned architect Stanford White in 1906. I rescued several of the individual bronze pieces from the jail when it was being demolished in 1973, I was 13 at the time and even then recognized their importance.
My clay model when it is completed and dry will need a rubber mold made of it and 3 plaster casts generated from the mold, a 4th cast will be needed to cut that narrow strip off of on the left side to use on the right side as this design will be laid out so it will have 3 repeats and a strip of that border on both sides like photo Nº3 below of my model 8B cast in plaster and given an antique nickel finish.
The purpose behind making a new and larger sized model now despite having the 8B version for many years which has sold fairly well, is so that I can make this design available in a larger hand-pressed terracotta
Were I to make a mold of the 8B the 10% shrinkage with the clay would make the end result unacceptably small and with less impact, it would wind up being almost a tile, so I decided a while back to remake the design to about 23-1/8? x 15-1/4? so that it will be the larger size I want, and to compensate for the shrinkage of both this model AND the pressed clay version so it’s final size will wind up being around 18-3/4? x 12-3/4?, the reason I want that specific size as opposed to say, 19×12 or somesuch is to allow it to be as close as possible to a standard size so that should a client desire to install one in a brick wall it should fit almost perfectly without having to trim bricks or make special arrangements just to get it embedded. Photo Nº2 below shows a rendering of how that works.
Now I have the size for the clay model calculated out to allow for the moist to dry shrinkage of the clay model (5%) plus the eventual 10% shrinkage involved with the hand-pressed clay version with it’s drying and kiln firing. Added to these two factors is an additional amount to make the resulting fired clay pressing close to the fired size of the Nortown D5 panel- 18-3/4″ x 12-3/4″
With that calculated out and plotted out on paper I have both my full scale reference print-out and the box-form required to start the model after a little more prep-work.
I’ll be making one section of the repeated design, making the mold of the one-section model, 3 plaster casts will need to be made from that and assembled into the rectangular panel shape, refined and touched up where the seems between them will be, and then another rubber mold is made from that which can cast interior cast-stone and, it will be used to make a rubber positive cast from to make a plaster piece-mold to use to make the hand-pressed clay sculptures.
It sounds complicated but in reality it’s simple, just a lot of intermediate steps. If I were to simply re-use the original sized design it would be much simpler, but then the resulting panel with the shrinkage would be considerably smaller, it would also be an odd size that if someone wanted to insert in a brick wall would demand special trimming and cutting of the bricks to make it fit.
Now I have the 3rd fired panel out of the kiln, I had lowered the final temperature 10º to 2050º and the end “hold” time from 10 minutes to 5 minutes. Also, I placed several kiln posts on the floor of the kiln so the panel could set on top of them on end and be raised about 1″ off the kiln floor and still allow the kiln lid to close.
It looks like this solved both issues I had, one was the red color I wanted had started turning towards the more brown spectrum for this clay at the 2060-2079º temperatures, so lowering the temperature to 2050 solved that, the nice rich red brick color I desired is there.
The other issue was in placing the first two panels in the kiln I had set them in place on end directly on the kiln floor, so what happened was the portion of the panel in direct contact with the kiln floor, and extending about 1-1/2″ across the face of the panel the clay did not reach the hotter 2060 and 2079º temperatures the rest of the panel did, so that narrow area turned the red color I wanted while the rest of the panel started to turn towards the brown tint.
This photo shows panel Nr 2 and Nr 3 side by side, the lighting was not ideal and I also had to correct in photoshop, but the left panel can be seen has an obvious lighter color band on it’s right side, that’s the end that was touching the kiln floor:
The right panel, Nr3 can be seen not only has a brighter red tone than the left half of the left panel, but there is no lighter color band on this one.
Now that I have the red color I want out of this red clay, and I know exactly what temperature it takes to do it, I can repeat the procedures and criteria and keep these pretty consistant.
The thing is, with kilns is that over time the thermocouple that controls the electronic firing sensor on the board tends to lose accuracy with wear and use, “wear” being defined here by X number of firing cycles. I added a digital pyrometer which was used for the first time for this firing, it pretty closely matched the temperature reading of the controller’s display before I went to bed when it was around 1750º. Unfortunately the kiln shut off about 20 minutes before I got out of bed, so I didn’t get to see exactly what temperature the pyrometer reached and how it compared to the controller’s temperature, next time!
I’m very pleased how the hand pressing has gone, none of the three panels cracked, warped or blew out in the kiln under the firing schedule I devised so I know the 36 hours and 57 minutes it took to fire this latest panel is not firing it too quickly. I could probably tweek the schedule a little to shorten the time but the risk there is hitting a critical tipping point and having a pressed piece blow out, also, just because a slightly shortened schedule might work fine, there could be the first firing with a different design and some slight difference in size or mass, or wall thickness could come into play and it’s just enough it blows out during firing.
So I’m going to keep this shedule where it is, shaving an hour or two off the 37 hour time isn’t worth it and saves very little anyway.