New model 8B continued

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.

New Art Deco model 8B finished

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.

 

New model 8b almost done

I have to finish the lower 1/3rd of this yet, I hope to get it done this weekend, but it is progressing nicely and I’m excited about seeing the eventual pressed terracotta version using 3 of these together to form a repeated design panel.

On the left is an original 1930 bronze from the Women’s House of Detention, 6th Ave, Greenwich Village,  NYC demolished 1973.

artdeco

Commodore Hotel cornice mask done

 

NOTE: This post never made it to the blog originally, it sat in cueue a long time, this model was finished a good year ago.

Here’s today’s model progress, mostly working on the right half:

The major modelling is now finished and he’s hollowed out, soon as the clay gets drier I will be cleaning up the surfaces and details.

Side view

New model 8B progress

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.

 

Model 8B continued

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:

 

New 8B model progress.

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 the moisture dries out of it. Right now the clay is still very soft and will be until I hollow out the back.

Art Deco D8 model started

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
form.
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.

Art Deco 8B panel

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.

ARt Deco D5 terracotta

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.

Art Deco 8B panel

I think I’ve all but decided I’m going to “remake” my Art Deco 8B panel with a new slightly larger model and issue it in hand-pressed fired terracotta  too.

The 8B design which I’ve had for years is this one:

8b

It’s 16-1/2″ wide and if I “convert” this to terracotta using the existing design the shrinkage of the clay will make it wind up in my opinion on the “dinky” side around at around 14″ wide, so I’m thinking that if I make a new model around the original size of my Nortown D5 panel it will wind up around 19-3/4″ wide or whatever I come up with so it would also fit the brick cources of a standard brick wall without having to do fancy extra cutting of bricks to make it fit,  if someone wanted to install it in a brick wall.

 

 

 

Butterfly child first cast

I now have the first cast out of the new mold, I gave it the tint base used for the Buff Yellow finish, though I also have this as a non official finish, it’s a pleasing warm color that reminds me of South Western adobe for some reason even though adobe clay and bricks are more of a pale red to pinkish color. Given an application of satin clear sealer it would look very nice.

Here’s another one with a little aging wash added:

It is 22-3/4″ x 19-1/4″ and 5″ deep, weighing about 40#

Winged dog cast

cast

Here’s a concrete cast fresh out of the mold for a client in Nashville that is going on his building.
I need to drill a hole in the bottom for a stainless steel rod, and after it cures a few days wrapped in plastic he will get an acid stain.

The cast weighs 150# so this one has to ship by truck!

The cast was acid stained and then a high quality oil based concrete sealer applied quite heavily as this will be installed in a very exposed location, so it’s a good idea to start it off with the maximum protection. The sealer does darken the color considerably but it will lighten up over time. The sealer and stain gave this a good antique look which will make it look as though it has been up on the building since it was built.

KONICA MINOLTA DIGITAL CAMERA

Metal casting

I decided to order a small amount of Brittania metal from Rotocast metals to do some metal casting, so  here’s five pounds of ingots to stockpile for now:I need to order another 5-10# worth yet. The brittania metal is 98% pure tin, the remaining 2% is comprised of antimony and copper, they were just about $100 for the five ingots, a tad bit less than $20 a pound.

So what am I going to make out of this?

Way back in the early 1990s I experimented with a few dog models, most were cast by a foundry for me in bronze, but one I had decided to try casting in Brittania metal for a set of bookends, this one pictured  below was one of them.

pewter

Making them was a real chore due to the processes I came up with at the time to do it, I had to first make a plaster/sand piece mold from the rubber molds I made to cast wax in for the bronzes, then I had to make a plaster/sand core for the inside to make the cast hollow assemble it all using brass pins to keep the core in position inside, and dry that out in the kitchen stove. Once I melted the metal in a deep fry pan on the gas stove I set the plaster/sand mold in a bucket full of sand and poured the metal into the mold. after it cooled I had to break the plaster/sand mold apart to remove the cast, the core remained inside the cast.

I had made two of them that way. I never made one for myself but I still have the original master rubber molds, so I want to have a bronze of each cast, and I also want to cast at least one in the Brittania metal again.

Somewhere I think I have notes on what I did, I seem to remember it took about 10# of metal, it was a lot cheaper back then too!