Make your own porcelain.

[HAuCl4]

For custom shapes this is the way to go if you want to save $.

http://www.ehow.com/how_2041701_make-porcelain-pottery.html

Please post other links, procedures, photos.

You can usually have a pottery school with a porcelain oven to "cook" your piece very inexpensively.

 

[Irons2]

To improve thermal shock resistance, add about 5% Petalite. It decreases the coefficient of expansion of the finished item. I tested mine by heating them white-hot and dropping them into a bucket of water. They didn't crack. It's fun to watch a glowing-hot crucible sitting on the bottom of the bucket, just boiling the water away.
Ball Clay has a fair amount of Iron in it. #6 Tile Clay is plastic enough that Ball Clay isn't needed and it fires White.

The best way to limit shrinkage is by using a low moisture mix and pressing it in a mold. Something to put that old Arbor Press back to work.

The key is high-firing the item before use to at least cone 10. I fire mine at about 1200 deg C. for at least 4 hours and let them cool slowly in the furnace.

I also found that the melting dishes that Lasesteve sells last much longer if refired at 1200 deg C. Now I make my own. The Clay they use sucks. It's not the thing to use if you want a very clean melt. Fore general use, they work fine.

 

[Lou]

I would like to get some big 4" X 20" X 3" porcelain boats or trays for calcinations. We use quartz for that but its lifespan is limited.

Anyone here good with this stuff?

 

[Irons2]

I would like to get some big 4" X 20" X 3" porcelain boats or trays for calcinations. We use quartz for that but its lifespan is limited.

Anyone here good with this stuff?

I thought about that for a bit. Someone would need quite a large Kiln to fire that baby. It's not just fitting the boat in the kiln, but minimizing the temperature gradient across the piece, so the interior would have to be substantially larger.
You could bake a whole Salami in that. :mrgreen:

 

[Irons2]

Some useful links:

http://www.sheffield-pottery.com/Raw-Materials-Dictionary-Glaze-making-Clay-Ingredients-s/36.htm

http://digitalfire.com/4sight/education/formulating_a_porcelain_282.html

http://baileypottery.com/clay/clays-chemicals.htm

http://www.lagunaclay.com/catalog/

 

[qst42know]

I would like to get some big 4" X 20" X 3" porcelain boats or trays for calcinations. We use quartz for that but its lifespan is limited.

Anyone here good with this stuff?

Hi Lou

Have you considered something completely different?

Like something off the tight budget shelf.

Corning PyroCeram cookware.

http://www.shopworldkitchen.com/corningware/stovetop-pyroceram-just-white-casserole-1096586

I have not calcined platinum but I have incinerated carbon soot directly from their surface with a propane torch.

If you are up for it, I can send a small bowl you can torture some and see if it will work for your application.

PyroCeram also comes in plate glass form as well.

http://www.onedayglass.com/pyroceram.php

Chris

 

[Irons2]

I would like to get some big 4" X 20" X 3" porcelain boats or trays for calcinations. We use quartz for that but its lifespan is limited.

Anyone here good with this stuff?

Hi Lou

Have you considered something completely different?

Like something off the tight budget shelf.

Corning PyroCeram cookware.

http://www.shopworldkitchen.com/corningware/stovetop-pyroceram-just-white-casserole-1096586

I have not calcined platinum but I have incinerated carbon soot directly from their surface with a propane torch.

If you are up for it, I can send a small bowl you can torture some and see if it will work for your application.

PyroCeram also comes in plate glass form as well.

http://www.onedayglass.com/pyroceram.php

Chris

I've melted Copper in Pyroceram. The problem is that the annealing temperature of Pyroceram is about 900 deg. C. Above that, the internal crystal structure begins to grow and the ware becomes brittle and will shatter if cooled too quickly. As long as you stay below the annealing temperature, it works very well.

 

[Lou]

900*C is fine for most of our uses. It just has to fit inside a 6" diameter quartz tube.


We do take Pt/Pd/Rh/other PGM blacks and put them into a quartz boat. They are for making sponges or sintered pre-forms. It fits inside a 6" diam quartz tube. The quartz boats are made of a 5" tube with two flat plates welded to the sides.

I just want something cheaper than quartz--residual alkali metal salts wreak havoc on it and devitrify it.

I also want boats that I can use for making sodium hexachlororhodate. Probably need about 15 of them, 5 for each metal and principal salt we make.


qst42know, I may take you up on that. I've heard of pyroceram, but have never used it. Always been a quartz guy. Though I do like my alumina and mullite tubes!

 

[nickvc]

It may be that I'm useless with a computer but I'm struggling to find a supplier in the UK for Corning Pyroceram cookware, anyone got any leads
I can find Corning cookware but not Pyroceram

I have found Visions and they claim it's Pyroceram will that be ok?

Edited for question.

 

[qst42know]

It may be that I'm useless with a computer but I'm struggling to find a supplier in the UK for Corning Pyroceram cookware, anyone got any leads
I can find Corning cookware but not Pyroceram

I have found Visions and they claim it's Pyroceram will that be ok?

Edited for question.

I use a Visions 5L casserole to heat beakers in on a simple coil type electric fifth burner. It has saved me lots of troubles and loses from boil overs. :mrgreen:

The white Corning pyroceram is advertised as their "Stove Top" line if that helps in your searches.

 

[HAuCl4]

Nice tips there guys. Thanks.

 

[Irons2]

It may be that I'm useless with a computer but I'm struggling to find a supplier in the UK for Corning Pyroceram cookware, anyone got any leads
I can find Corning cookware but not Pyroceram

I have found Visions and they claim it's Pyroceram will that be ok?

Edited for question.

I bought my pyroceram collection off of fleabay. The new prices are ridiculous. Corning had a big production facility in France for making Pyroceram and Visions ware, so you might check local auctions.

Visions is the follow-on to Pyroceram. It has better heat transmission in the IR wavelengths. The manufacturing technology is similar but the material is different, a solid solution of beta Quartz. I would buy the older Corning production. They sold their facilities, and even though the name is the same, the quality control leaves much to be desired.

Another example of the damage that 'Bean-counters' do when they take a great product and chose margins over quality.

 

[Irons2]

It may be that I'm useless with a computer but I'm struggling to find a supplier in the UK for Corning Pyroceram cookware, anyone got any leads
I can find Corning cookware but not Pyroceram

I have found Visions and they claim it's Pyroceram will that be ok?

Edited for question.

I use a Visions 5L casserole to heat beakers in on a simple coil type electric fifth burner. It has saved me lots of troubles and loses from boil overs. :mrgreen:

The white Corning pyroceram is advertised as their "Stove Top" line if that helps in your searches.

The Pyroceram ware numbers start with a 'P'. Not all of the Corning ware is rated 'stovetop-safe.'

 

[DONNZ]

I agree, this is a good thread.
So good, I'm totally lost. It's Irons2 links to recipes that did me in.

Just finished two molds make from plaster of paris and need a grog recipe to pour like a slip.
A one part mold and one two part mold.

A helping hand is need with the grog.

 

[Irons2]

Grog is nothing but refractory filler that has already been fired. It's like adding sand or gravel to Cement. The size of the Grog depends on the application. It is added for several reasons: It helps the workpiece dry quicker, it increases stiffness to the finished work, it can increase the working temperature and reduce shrinkage.
Molochite is pre-fired Kaolin and, when added to the mix, helps in the formation of Mullite crystals. Even though it's a bit pricey, I like it because it has the same coefficient of expansion as Kaolin and it fires white. If you need something for high temperature work, Aluminum Oxide is a good choice.
25% or so is a good starting point. If you add too much, the Clay becomes difficult to work with, but since pressing is the preferred method of production, you can get away with a stiffer mix.
If you are casting, read the excellent article on the Laguna Clay site on preparing slip clay and save yourself a lot of grief.

Be sure to use a water soluble mold release on your plaster mold. Green Soap is pretty much standard. The plaster mold will wick away the Water in your slip, so it needs a release that will pass the moisture.

When you remove your work from the mold, cover it with a damp cloth and allow it to dry slowly over several days, otherwise it will surely crack.

 

[DONNZ]

Thanks Irons2,
A starting point needed.

Out looking today and found a couple of sites that may be worth saving:

A recipe for Insulating Fire Brick
http://members.optusnet.com.au/terrybrown/FireBrick.html

Technical Help: One of yours.

Digitalfire Ceramics Technical Articles
http://digitalfire.com/4sight/education/index.html

There's a homemade Ball Mill Stand that's worth reading. With detailed pics.
http://digitalfire.com/4sight/education/make_your_own_ball_mill_stand_333.html

 

[lazersteve]

I would like to get some big 4" X 20" X 3" porcelain boats or trays for calcinations. We use quartz for that but its lifespan is limited.

Anyone here good with this stuff?

Lou,

I bought two fused quartz boats from TGP (Technical Glass Products) last year for my tube furnace work.

Here they are:

Unfortunately about the time they arrived, I quit calcining my Pt and Pd and switched to hydrazine and/or zinc conversions.

So now I need to find a new use for them.

Steve

 

[Lou]

Those are somewhat like ours, except smaller.

Thinking of selling them?

 

[lazersteve]

Lou,

I haven't considered selling them. Instead I hope to put them to good use.

Steve

 

[Palladium]

Irons is right from what i have always found with “True” Pyroceram. Look for the P. I buy mine from trade days for dirt cheap all the time. I have many! I have tried to abuse them just to see what they would take. I have done everything from melting to incineration in some just to see what the limit was. So far so good! I'm a believer!!!! I can't endorse it enough.