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Mark C.

Member Since 09 Jan 2012
Offline Last Active Today, 01:08 AM

Topics I've Started

Iron Crytalline Glaze Cone-Oxidation Or Reduction-Cone10

Yesterday, 08:38 PM

OK this is arare event-a glaze in magazine that turns out exactly as in the book.

I was reading last months CM (ceramics monthly) and saw a iron glaze that caught my eye

So I mixed it up as a sample in 1,000 grams and tried it in a reduction fire to cone 10 and a half

It also works cooler as well in a cone 9 area of the kiln-slow cooling=more cystals

WOW it turned out eactly as in the photo-now thats a rare thing folks.

Heres the recipe out of May CM issue

Its credit goes to emerging artist Alex Thullen-not sure if its his creation?


Iron Crystallineglaze cone 11-12 Oxidation


Synthetic bone ash----12%



Custar Feldspar---------48

EPK Kaolin----------------6

Silica (325 mesh)--------16


add Red Iron Oxide(synthetic)-11.5%


I suggest using these exact ingredients for best results

get some high purity iron and the right bone ash

most should have the rest lying around in the studio

You can see his photo on the May issue page 87

Heres some of my work after a few more fires using this glaze and mixing up a 10,000 gram batch

one last note this stuff will stain your clothes if you get it on them-I use glaze clothes every week but many may not have a set-you will after working with this one you will have a set.



PS could a moderator please move this to the glaze forum as I posted it in wrong space-thanks

A Far Away Gallery-How To Supply

30 May 2015 - 04:53 PM

I have had an outlet that is about 3 1/2 hours away from my location. Thats one way so its a 7 hour drive.

I have had this gallery for many many years and trust the folks.

I used to go thru this area but due to  some show changes it off my path now.

So once a year I drop a huge load of work off and then a few other tiomes a year when friends head thru I send them a few boxes. I should mention this is consignment gallery for me so they mail me a monthly check.

I collect work for several months and a few days ago I made the round trip drive to drop off 45 boxes at there home/shop. This was a fullpickup bed(8 feet stacked two full layers tight.

This arrangement works for both of us as I only have to go there once a year.This drop is worth 18-20K retail and is the most work I take a gallery at one time.

They have a summer tourist season (Mendocino in nor-cal)and a slow winter season.

This gallery is my best consignment outlet the past few years-they change over time as well.

Now I started off with more drop offs years ago and this has morphed into this once a year deal as it makes the best use of my time.


Reading Cones

30 May 2015 - 04:42 PM

This was brought up a week ago so I thought I would add some info.

These cones  I show will apply to whatever temp range you are working with-as the position of cone is key whatever range your in. It will not matter if its cone 06-cone 6 or cone 11-the bend in whatever

Now first let me say that you should have 3 cones in your pack not the two that I show

This will tell you more info-I use two only because of my specific needs and experience.

Also these are for the large cones only-small ones are not made for this visual use.I make my own cone packs from scrap porcelain clay

Never use wet clay as they can blow up and you need cones to really know whats going on in a kiln and cones are the best refreence you have-no matter how you like your digital controller and trust it.

Lets say you are firing  to cone 6-that means you will need a cone 5 a cone 6 and a cone 7 in your pack.

I premake mine weeks before needed so thay are dry.I make 8-10 pads at a time

Make your packs so the cones do not fall onto each other they need to fall free and away from each other-that way you can read them in the spy hole.If you cannot see them but a small brick behind them which makes it easier -also use the right eye proctection when viewing cones in kilns as you can damage your eyes without the right glass.-You can look this up as this thread is about reading cones not the glass to use.

Now cones can fall all at once or separately or in between thats just the way it is. Whats important is the cone you are firing to.

There is some good info here so its worth your time reading


As you can see using a clock face is good way to talk about where a cone is-3 oclock is 1/2 way down

1 oclock is a soft tip etc.

When I fire I'm usually going to what I refer to as a soft cone 11 that is to say I want that cone to read between 1:30 and 3 oclock (this is in referance to a clock face or if you read the link above you will understand this now and what it means as to temps)

I choose this time depending on how long my fire is going. Fast fire vs slow fire.There is a time temperature relationship.Many call this heat work-heat work is something you should master and cones can help.

Glazes will melt more if you fire them longer than if they are fast fired with same cone bend . A 12 hour fire say vs a 7 hour fire. Or at least that is my experience in my gas kilns.

So if the fire is long I choose a softer less bent cone .I hope this is cear.


So in the groups of cones in second Photo-they are

Group A is cone 10 end point soft cone 11-that means cone 11 is 1:30 to 3 oclock-this is what I fire to usually

Group B end point cone 11the tip is equal to the base-this is what I fire to in a fast fire

Group C whoops its way past cone 11 and got away from me.All cones (10-11) are flat-this is what happens when the phone rings or friends are visiting while glaze firing.


In the first photo it the dilemma what to do with your cones???

I pile them up and every year toss them out


Store & Forward Credit Card Processing

21 May 2015 - 08:12 PM

If this sounds like pay it forward well its not exactly like that.It's pay yourself forward.

For those who process credit cards it means that when you cannot access your server (due to signal loss)you can still swipe cards and later download the info when the connection is good.

For many decades now this was only done with wireless credit card machines that charged a lot of monthly fees-Now you can do it on your smart phone.

This is big news and it works well.

say your phone is in a NO service area (some of you city folks may not know this exists) this means the connection is so poor the phone cannot send the data.You still may be able to talk but the credit info say on the square reader is stuck in spin mode.

With the square reader you can now go into your account and put it on store forward and that means you can take acards and when you get into a better area connection wise it sends the data and you are paid.

Now I should metion that this comes at some risk as the cards cannot be verified so you could take a bad card and it will be your loss.

You can now do this with the square and a smart phone-other readers should fall into line soon.

Happy swiping.


Avatar Issues

21 May 2015 - 03:32 PM

Something is wrong with the new software that makes it impossible to post an avatar. 

I suggest to anyone who has an avatar to leave it alone until this issue is repaired. I have been trying for weeks now to get an avatar after trying to upgrade a new one.

I have had little feedback on this except from Bruce so I'm posting this notice here so you leave your avatar alone if you have one.

If anyone can get to the bottom go this please post it here so we know its fixed.

Mark C.