Help wanted: how to soften hard oil clay?

[sculptor]

I've recently removed the clay from the mermaid armature so I could us it in my lifesize screaming man piece.

I had bought a lot of #4(hard roma plastalina) so it would hold detail.
Problem is: it is darned difficult to work unless I warm it in the oven first, and then beat and roll it continuously as I work-------this slows me down alot and is darned tough on my wrists--------so I wanna soften it.

I have mixed some with old softer clay which hepled a little, but not enough.

Previously, I had mixed old clay together, and melted it in a double boiler, then mixed it in a bucket with a drill and old boat propeller, which made the mixture softer than any of the ingredients. Maybe from entrained air?

I was thinking that maybe mixing in some mineral oil, or soft wax might help.

I would love some advice or stray ideas here.

rod(sculptor)

[rderr.com]

Try 1/2 lbs pieces in the microwave for 10 seconds. Be careful of traped air, it can be very hot. If you lived down here you could park the car in the sun and melt lead inside on a cloudy day.

Happy New Year

Robert

[sculptor]

uh gee
1/2 lb pieces
lets see----------at about 180-240 lbs/lifesize piece thats 360-480 1/2 lb nuke trips
----------(and I was hoping for a simpler solution)
sigh
gee i almost wish i lived "down here"

Anyway:
Lemme tell you a little story about Dwight Kalb and the forgotten clay in the oven
Once upon a time, and a very long time ago it was.....................
We were sculpting in the studio.....when....
a faint knocking was heard at the door----one of the guys opened the door and announced that it was Dwight's wife------someone else remarked in surprise---"She never comes out to the studio"........
Dwight went to the door .....there followed a hushed conversation....following which-----Dwight scooted to the bathroom and then out the door carrying a fire extinguisher...... after a small pause, we told the model."take ten" and I followed Dwight.
I arrived at the kitchen door in time to see(through a dense black smoke) Dwight kick open the oven door, aim the fire extinguisher inside, and let her rip---hacking and wheezing, I helped him open the kitchen windows in the midst of a cold Chicago winter, and we retreated to the studio.
No sooner had we resumed work, when we heard the ominous sound of a fire engine stopping in front of the house.
"Do you think I should go and see them?" quiried Dwight.
I responded "Dwight, they have axes, and if you don't open the door, they'll just let themselves in"
He scooted with reasonable haste to greet his guests.
Once again, we told the model "take another ten".
And, I followed Dwight.
When I got to the kitchen, I saw (through the dense black smoke which layered from about 4 feet off the floor, to the cieling)the legs and lower bodies of Dwight and 5 or 6 firemen standing arround the stove as Dwight told them the story. As he finished the story, he had extracted the pan of blackened smoldering clay and was showing it to the firemen.
Their captain perused the blackened lump for a few minutes, then asked Dwight.."So, what are you gonna call it?"
I departed laughing.

[fritchie]

Originally Posted by sculptor

uh gee
1/2 lb pieces
lets see----------at about 180-240 lbs/lifesize piece thats 360-480 1/2 lb nuke trips
----------(and I was hoping for a simpler solution)

Rod - I sympathize with the hard clay problem. I always have used a medium-hard oilclay, but even that hardens if it sits a long time. And I did have your experience about mixed clays being softer, but that was a disappointment for me, as my clay already was as soft as I wanted it to be. I tried to mix some white from a different manufacturer with the dark gray-green I normally use. I gave the rest of the white to a beginner.

You might use heat lamps to soften the clay bit by bit. I do this regularly on cold days, but with a regular 100-watt light. You could cut it off as it softens and then proceed.

Somewhere early in this forum I believe, or possibly in Russ’ old forum, a person who seemed familiar with clays said that the softener used is a heavy oil, such as automobile engine oil, but probably purified for color. That suggests any clear mineral (not food or organic) oil might work. Try a small bit first.

[dondougan]

Oil-based clays are basically natural clay flour, oil or grease, and wax in various proportions.

When I was a student years ago George Beasley (Thanks, George!) gave me this formula for plasteline:

20 lbs. microcrystalline wax
50 lbs. clay flour
6 qts. motor oil
2 or 3 lbs. grease

If you add more oil the clay becomes more plastic, if you add more wax the clay becomes firmer.

Melt wax in double boiler, add grease & oil and mix - then add clay and mix.

I have found that mineral oil also works well for the oil. Every several years I find my plasteline clay needs to be made more homogenous because of drying-out of long-stored models, studio dust (I carve stone) etc., and I often just throw all the odds and ends in the pot, as well as any store-bought stuff I have recycled from students who didn't want their old projects. I mix in a metal pan or a double boiler for safety, with plenty of ventilation. I stir with wooden spoons or long-handled paddles I've made.
I usually work directly over a hotplate burner with my studio door wide open.

To form easily managable slabs I pour and trowel the thick mixture into flat plywood trays with 1x2 sides and lined with polyethelene sheets. After they have cooled they can easily be cut into convenient size slabs for use or storage.

Don

[sculptor]

Originally Posted by dondougan

Oil-based clays are basically natural clay flour, oil or grease, and wax in various proportions.

When I was a student years ago George Beasley (Thanks, George!) gave me this formula for plasteline:

20 lbs. microcrystalline wax
50 lbs. clay flour
6 qts. motor oil
2 or 3 lbs. grease

If you add more oil the clay becomes more plastic, if you add more wax the clay becomes firmer.

Melt wax in double boiler, add grease & oil and mix - then add clay and mix.

I have found that mineral oil also works well for the oil.
Don

Thanx Don and George-----one of my sculpting fellows (Dwight-mentioned above) had mentioned making his own clay---but I hadn't gotten his details.
Yours fills that void.

as/re "grease" any old grease? or should I use lithium grease--and I'm guessing that the grease also would make the clay more plastic. True?

I was already using heatlamps and a clay oven i made(after Dwights fiasco) using 2 light fixtures and a piece of sheetmetal duct, but could only process a few lbs at a time, and when throwing up a large shape the tedious ponderous slowness really scraped the edge off my creative process.

i'm gonna copy and paste and print the above.
rod(sculptor)

[dondougan]

RE: "grease" = "any old grease? or should I use lithium grease--and I'm guessing that the grease also would make the clay more plastic. True?"

I've used lithium grease made for automotive use, and yes, it does make it more plastic too.

[kschmidt]

I warm my plasticine clay by submerging it in warm water in my crock pot. I set the crockpot on "low", and place several chunks of clay 2-4" square, fill the pot with warm water, and wait until the clay gets soft. Each time I pull a piece of clay from the water (drying it on a paper towel), I put a new chunk in. I monitor the temperature of the water and turn the crock pot off it it gets too warm. I also put a Post-it note on my door so I won't forget to make sure the crock pot is off when I leave the studio. So far this works for me.

[rebin]

hi could anyone please explian what the microcrystalline wax is? and what dose lbs means?

thank you

[Funes]

Microcrystalline wax is a type of parafin wax - generaly more flexible than standard wax, shorter less branched hydrocarbon chains if you want to get chemical about it.

Lb - short for Pound ( as in weight, not money ) - 454g. Lb itself comes from the latin Libra - scales.

I'm going to have to try out that recipe for "I can't believe it's not plastecine"

[hoffel]

if you are having trouble finding microcrystaline wax try a pottery supply store

[rebin]

thank you funes.for your help. can i mix parafin with normal wax to get it?

[rebin]

thanks hoffel. i will try

[rebin]

can anyone tell me please, how much one gts is in liter?

thank you

[dondougan]

Google search "qt to liter"

http://www.upenn.edu/oip/iss/handbook/measure.html

[anthony pittare]

I know some people build a heat box when using roma.

Use a normal cardboard file box. line the inside with aluminum foil, leave the handles clear and open for ventilation. cut a small opening in the lid for a 60 watt light bulb and PRESTO. leave the clay in there to heat up and you golden. oh and for when you are working on the sculpture use and alcohol torch to soften the areas you need.

anthony pittarelli

[Ameenah]

I hate trying to carve tiny chunks of clay to work with so i put the block of clay in a thick ziplock wrap that with a towel, take it out to the garage and run it over with the old Chevrolet capri a time or two then I can just break off some and warm it. To warm my clay I use one of those candle warmers. You place a ceramic tile or ceramic bowl on top and it works great. If it gets to hot put lift the bowl by placing it inside another. I also put a bit of oil in the bowl to keep the clay from sticking.

-Ameenah

[GlennT]

I use Chavant "Le Beua touche" clay which is not nearly as stiff as Roma .
Sometimes I use NSP which is stiff. What I do when using either type is to take a spackling knife (putty knife, trowel) with a 4 inch wide blade, and made of a thicker gauge than the cheap type. I then slice thin sections of the 2 lb block of clay, kind of like slicing a loaf of bread in appearance. This makes pieces that are easier to work with, and if I need them softer I just hold them in my hand until they warm up a bit. In the rough-in stage where you need more volume at a time, I just apply the slices cold and stiff and knock them into the armature with a rubber mallet.

[Musicman92130]

I also use Chavant Le Beau Touche clay and I usually warm it in a bucket with a clip on light (150W). I really like this clay, but if you use this type remember not to melt it completely. It doesn't reconstitute and if it melts it is ruined. And this clay isn't cheap.

Mark

[ahirschman]

I use Chavant Proffesional Plasticine, NSP and have used La Beau Touche (But it is too sticky for my taste).

Here is what I have been doing lately (Depending on how old the clay is).

First, I take my 10 lb block (or 2 lbs if that is what I find) and place it under heat lamps. I regulate the heat by changing the distance of the lamps.

The lamps will warm up the surface, and I use a knife or spatula to cut the warm sections away. I still need to knead the clay a few times to get it pliable, but it is much easier when it is a little warm.

I will place a piece of wood on the floor (Plywood) and throw the clay a few times on the floor. This really works well. If the clay is old and stiff (Which I have many times) I will add a little petroleum jelly (or baby oil) and fold it a few times before throwing it.

If the clay is too hard to handle I will warm it up a bit, add (or not) petroleum jelly (a tiny amount) and then use a 3 lb sledge hammer to get rid of some of my pent up aggression on the clay... Works very well.

I also place clay in the microwave, but I am not too careful and tend to overheat the stuff. Then it smells, but it gets very soft (I still have to use the sledge hammer to mix it up).

The heat lamp has worked very well, because it warms up new layers as I use the ones I removed and keeps some clay ready for me all the time.

Hope this helps.

Ari.

[Thatch]

I lost 6 months of work because of some incorrectly mixed slurry that was used with the silica to make molds over the waxes and the guy who was pouring just kept going and broke every mold and watched the bronze run all out into the sand trap. Now I want to work in something else and make molds so I can make more than one wax. I am still very angry about losing all my work. Well enough about that.
With the plastic clay recipe I think I will try using parrafin (Gulf Wax) because I can get it anywhere, and use mineral oil. I can get mineral oil by the gallon (almost 4 liters) at a store that sells farming supplies as well things for horses. I use mineral oil as a penetrating oil for my work in wood before using tung oil to finish it.
Petroleum products are not good to have penetrating your skin and getting in your system especially if you do it all the time. The synthetic motor oils might be different but the jug of horse mineral oil was $15 the last time I bought it which is less money and good for your skin.
The Gulf Wax can be bought in almost any grocery store here in Texas in the part of the store that has the supplies for putting up jars of jelly or black eyed peas. It is called canning but is all put in jars, for those not used to the English misused in the US.

Thatch