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timbo_heff

Member Since 24 Apr 2012
Offline Last Active Yesterday, 11:38 AM
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#87803 Vent Not Turned On During Bisque

Posted by timbo_heff on 26 June 2015 - 03:05 PM

The vent is for the wares and the potter but since the clay is now sintered, rebisque fire will not get any more of the potential problems out; once sintered, the clay cannot release those gasses until near top temp when the clay is as close to molten as it gets.




#82241 Manual Sitter Vs Digital Controller; Your Preference?

Posted by timbo_heff on 22 May 2015 - 01:52 PM

Bailey kilns are nice nice :

they are Cone Arts wearing a Bailey t-shirt




#75834 Standard Clay #762 Questions

Posted by timbo_heff on 20 February 2015 - 01:42 PM

Don't worry about the shinkage in terms of glaze fit: It is COE that determines glaze fit

Shrinkage and COE are not related.

Do your test tiles with the glazes you want to use:

If they are too loose or too tight, adjust the glazes.




#73453 Ceramic Fiber Body

Posted by timbo_heff on 16 January 2015 - 12:59 PM

Ceramic fiber is spun Kaolin clay: like fiberglass but much more toxic.

Paper fiber is just that: paper: easily made by putting a roll of toilet paper in a small bucket of water:

 

As Colby said above, the paper does not make it more translucent, but what it does is give you the ability to make super thin slabs : hence you can make more translucent objects.

The clay is not more translucent but a thinner wall will pass a lot more light than a thicker wall !




#73402 Ceramic Fiber Body

Posted by timbo_heff on 15 January 2015 - 03:07 PM

Hi, You must mean paper fiber !

If so then yes!!!




#68366 Pottery Wheel Suppliers

Posted by timbo_heff on 22 October 2014 - 11:36 AM

What Diesel says is IMPORTANT !!!

Without a CSA inspection sticker you put yourself in peril in Canada.

All electronic devices in Canada NEED to be inspected.

What happens is that if there is a fire, your insurance company can deny any claim since it could have been started by your non-approved device !

 

Order a wheel from Tucker's or one of the other Canadian retailers. They get all wheels approved and deal with import hassles as well. Looks more expensive at first, but once you get your feild inspection and pay tariffs, you will find they are the same price or cheaper and do not endanger your home insurance!




#68225 White Crystals On Fired Vase

Posted by timbo_heff on 20 October 2014 - 12:41 PM


 

The suppliers sell these 6 to10 thingies this way to keep from having to stock SO many clay bodies for all the various firing temperatures.

 

...................john

 

Another reason clay makers have these compromise 6-10 bodies is for studios that have cone 6 and cone 10 kilns: prevents major mishaps in favor of minor mishaps (;




#64308 Cone 6 Body Or Cone 6-10 Body: Much Difference?

Posted by timbo_heff on 11 August 2014 - 12:02 PM

 

How does one tell if its cone 6 is under fired , or cone 13 is over fired ?

 

Plot the Apparent Porosity curve and look for the minimum.  It'll be a U shaped curve.  That is the cone that the body is "mature at" and should be the firing cone.  The flatter the bottom of the curve, the more "forgiving" the body will be to firing variations within the kiln as well as for general under or over firing.

 

You also then align this information with a MOR test curve for strength.  You are trying to get the minimum porosity and the maximum MOR to basically overlap on the same cone. 

 

3 percent porosity is a LOT.  Asking for issues in functional tablewares, in work destined for outdoor installations, or things like pool tile, and sinks and such.  Shoot for something below 1%.  The closer to 0 the better in general.  0.5% is a nice optimal target..........hard to hit without dropping the MOR.

 

best,

 

....................john  

 

 

 

How does one tell if its cone 6 is under fired , or cone 13 is over fired ?

 

Plot the Apparent Porosity curve and look for the minimum.  It'll be a U shaped curve.  That is the cone that the body is "mature at" and should be the firing cone.  The flatter the bottom of the curve, the more "forgiving" the body will be to firing variations within the kiln as well as for general under or over firing.

 

You also then align this information with a MOR test curve for strength.  You are trying to get the minimum porosity and the maximum MOR to basically overlap on the same cone. 

 

3 percent porosity is a LOT.  Asking for issues in functional tablewares, in work destined for outdoor installations, or things like pool tile, and sinks and such.  Shoot for something below 1%.  The closer to 0 the better in general.  0.5% is a nice optimal target..........hard to hit without dropping the MOR.

 

best,

 

....................john  

 

Here Big Lou:

This graph shows how little range is where it is vitreous but still at max strength : and this is from a clay that is touted as having a much better range than most commercial clays:

(Matt and Dave clay: out of business though)

matt dave SCIENCE 25

 

 

 




#62419 Non-Legal Ways To Address Copying Issue

Posted by timbo_heff on 14 July 2014 - 11:36 AM

How about "sharing" your info but make it all incorrect thereby sending them on a big huge waste of time failure!




#58558 Are Dinnerware Safe Glazes Safe?

Posted by timbo_heff on 15 May 2014 - 10:54 AM

Send samples to Brandywine or Alfred for testing: that is the only way to know with confidence.

Doesn't cost very much... a bargain at twice the price




#57710 Reduction - What Is It Good For?

Posted by timbo_heff on 01 May 2014 - 02:33 PM

And there I was thinking I was having amazing deja vu experiences!!

In Scotland, "Hey you get offa macLeod!"   drew quite a different reaction to the track

Or were the stones amazingly futuristic??

"Hey you get offa my cloud"  Ah! things are so cyclic when you are as old as I am, makes me feel so "connected" :rolleyes:

This was on Garrison Keeler Prairie Home Companion so even though pretty off color, if it's clean enough for Garrison it must be clean enough for CAD:

 

Do you know the difference between Mick Jagger and a Scottish Highland sheep herder:

Mick says 'Hey hey you you get off of my cloud.'

and the sheep herder says 'hey hey McCloud get off of my ewe.'




#57643 Trimming Issues

Posted by timbo_heff on 30 April 2014 - 12:12 PM

Get a utensil crock from your kitchen: center it, attach to wheel with clay, coil some clay on the rim, cover with supermarket bag plastic to not muss up your new pot too much: Easy trimming chuck for most bottle shapes




#55901 Stacking Cone 6 Greenware In Bisque Firing

Posted by timbo_heff on 01 April 2014 - 01:33 PM

Be careful with the brown stoneware: those can bloat in the glaze fire if they don't get enough oxygen in the bisque fire> I would not tumble those but give them plenty of room




#55634 Porcelain Balls

Posted by timbo_heff on 28 March 2014 - 12:20 PM

How about a melon baller ?




#52704 Great Video On African Forming And Firing : Wow!

Posted by timbo_heff on 16 February 2014 - 10:27 AM

 I hand-built this yesterday after watching the African documentary above.

 

Did the technique of pushing and turning it into a round mold : 

Foot ring from the same mold.
Went a little kooky with the decorations, but a just for learning pot anyway.

(white stoneware with a little grog. banana for scale)

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