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Mark C.

Member Since 09 Jan 2012
Offline Last Active Yesterday, 07:40 AM

#122461 Really Pushing It And Not Having Problems

Posted by Mark C. on 18 February 2017 - 04:23 AM

You have to push to find the limits-once you realize what you can do with the particular clay body  you use and climate you live in and firing cycle you are doing you can find many of the preconceived ideas do not hold water anymore. I will add at some point you will find the wall and have to back down the speed-weather drying handling or firing or cooling .

I think most in ceramics baby the work but they can afford to as its not a living. We you find the limits are not where you thought  and you will move into another level of production and realize what may be possible .This also applies to other processes as well.

Just when you have it figured out is when the c ceramic gods step in and crush you with a ruined load or bad glaze or bad clay or 10,000 other issues that go sideways-it the nature of ceramics.

#122460 Qotw: What Kind Of Kiln Vent Do You Use?

Posted by Mark C. on 18 February 2017 - 03:11 AM

My electric kilns are outside and are only rarely used and only for bisque and are unvented.-gas kiln has a 10 foot brick and  12 foot stainless steel stack.

Winter is still home raining like crazy in the 30's at night-here in Cambodia its daily into the 90's and nights are cooler.

#122386 Clay Brick Factory In Cambodia

Posted by Mark C. on 16 February 2017 - 08:39 AM

In the pottery area about 2.5 hours outside Phnom Penh there is a very old brick factory.

This country is built on these type of bricks. They are used everywhere for everything . From buildings to walls .They are usually skim coasted with cement after laying them up..This factory is very old the 5 kilns are huge long camber kilns on a hillside-fired with local wood.

Two of the 5 kilns where firing when we dropped by for a look . One woman was lightly stoking one kiln. They mine the clay from river and extrude the bricks  and slow dry in shade and fire -They haul them up hill by hand and load kiln in side chambers-after firing they unload and carry down the hill. I crawled into one empty chamber about 1/2 way up hill and took the photo looking down hill toward stoke hole-these kilns are a few hundred feet long.This place was all manual labor except for a backhoe and power extruder..The clay is brown until low fired to an orange teracota color. All bricks have 4 holes in them.

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#122383 Cambodia Japanese Sponsored Pottery

Posted by Mark C. on 16 February 2017 - 06:36 AM

I'm in Cambodia  with my wife and am visiting my sister for 10 days who lives in Phnom Penh for six months (retired school teacher from US) for fun.

We hired a driver and went on a long day trip out of the city to the area that is known for making pottery. Its about 2.5 hours out. Most is earthenware but there is a Japanese sponsored pottery where they make the clay and glaze from traditional materials and fire to high temps(cone 10) with wood. They sell this ware to  a few high end restaurants in a few cities. Phnom Penh and Siem Reap where we just spent 3 days viewing the Temples.

In the potteries in the country each house in up on stilts and the pottery in underneath. They fire with rice hulls and wood to low temps.

The only exception is the Japanese Pottery.It a low production deal. They had about 4 treadle wheels (sit down) They did have a huge pug mill and a few power grinders to crush stone/rock and shells for glaze and clay making.

Heres the kiln-I will post more on this area next month when I'm back home. My trip is packed full and not much down time until I'm home.I have taken lots of photos. We leave for Indonesia next week and not sure on internet connections on small island we will be diving from.


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#122214 Clay Buyers Guide

Posted by Mark C. on 13 February 2017 - 08:27 AM

I want a porcelain that fires hard as nails is translucent and is super cheap ((300$)a ton) only needs 1,000 degrees to mature (for low firing cost)Has great throwing legs will not crack and has zero platelet memory hand builds great throws great fires SUPER white.I have few other requirements but this is the short list. Any suggestions on a where to get this body???

#121883 Clay Has Memory - Applied To Wheel Thrown Forms

Posted by Mark C. on 07 February 2017 - 03:32 PM

I make square bowls

Here is how clay has memory in a thrown form.

I throw say a 1.5# cereal bowl-round-let dry to trim state 

Trim a foot and rewet with sprayer-paddle it square

This is common form for me.

In the glaze fire  the square bowl tries to go round again-just a bit-its like it knows where it was at one time and is trying to get back there .

The more square the bowl is the less it can go back round.I make this square bowls in regular and chopstick bowls with a fee notches in the rims for holding high quality chopsticks -I bought a few cases of square sticks a few decades ago with gold bands.Almost out now-so much for a lifetime supply idea.

As to teapot spouts that an easy one as its written on my wall in shop they always (if you throw on a standard direction wheel) will unwind in a clockwise manner looking at the spout as stated above.

#121880 Wheels/coasters For Northstar 30" Slab Roller

Posted by Mark C. on 07 February 2017 - 03:10 PM

I'm understanding that the Northstar legs are to wimpy ??

Instead of metal reinforcements how about a piece of 3/4 plywood with the rollers on that and the table sits on that-then you have a shelve under to store stuff and it all rolls around.

I will say I'm not a Northstar fan as the stuff is made for light duty-they are getting better but your issue reminds me that they are not yet there.

#121875 Natural Kiln Venting

Posted by Mark C. on 07 February 2017 - 02:31 PM

I have been firing an unvented bisque electric kiln outside for over 40 years.I also did low fire glaze and lusters in outside kilns before they even had vents. Vents are for removing fumes and since you are outside I would say forget it.

#121861 Qotw: What Inspires You In Your Work, And How Do You Incorporate It?

Posted by Mark C. on 06 February 2017 - 11:51 PM

I see fish underwater and later make a very loose wall fish from that memory or underwater photo. It a loose process these days.

#121860 Pottery Display Rack

Posted by Mark C. on 06 February 2017 - 11:50 PM

Top shelve is 60 inches 0r 5 feet she said -Its a guessing game on width-until she answers, but my guess in 5 and 1/2 feet wide (66 inches) looking at the spread in her photos. I love a good guess.

#121811 Why Didn't Someone Tell Me About Paperclay!?!

Posted by Mark C. on 06 February 2017 - 12:50 AM

I love this statement

(I'm wondering if there are any pitfalls I'm overlooking)

Well let me say straight up that in my 40 plus years full time in clay the pitfalls never end-that's right NEVER end

So in ceramics you can count on pitfalls-its the one constant .

Just when I feel I have it down wham pitfall.

It can be from the kiln to the clay from the glaze to the kiln gods-even the customers can cause a pitfall.

There may be less pitfalls with moon shot or space walk but it will cost you more.

#121790 Hydrometer

Posted by Mark C. on 05 February 2017 - 03:46 PM

Pug just to be clear-I have a glaze that likes to be about 1520 on the hydrometer scale.

That same glaze weighed up in the 100Ml plastic tube (which also includes the tube weight as its not tare off) is 194 for my optimum best results 

Its fast as I can stir the glaze pour the 100ml full to the line plop it on a scale and adjust it until it weights 194 by adding more water or more material.

It best to always remain on the add water side as it easier to add water than mix and sleeve more glaze to make it heavier.

#121751 Vitrify

Posted by Mark C. on 04 February 2017 - 05:56 PM

I assume you mean Maxwell's

No it's not maxwells hammer


as to your mugs if they weep its not good and I would toss them.Think of this as throwing lesson

#121727 Fractured Kiln Shelves...

Posted by Mark C. on 04 February 2017 - 12:38 PM

Have you thought of switching to advancers ?Big upfront cost but huge space saving, They do not like thermo shock. Maybe you got a bad batch of the cordilite ones. Do you use 1/2 shelves at all? and if so are they cracking as well?

#121656 Kiln Wiring 3Phase To Single Phase

Posted by Mark C. on 03 February 2017 - 11:00 AM

In our area most industrial sites (old lumber mills -heavy equipment shops state colleges ) all had three phase. Most residential areas do not have 3 phase

on the poles .So most homes could not hook up a three phase kiln.