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Member Since 31 Mar 2010
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#124351 Sio-2 Clay - Porcelain(Black) - Black Ice

Posted by Min on Yesterday, 11:33 AM

I've messed around a little with Plainsman's Polar Ice, it comes extremely wet also. This is from their website and the reason behind mixing it so wet. No clue if this is the same reason for your black porcelain being so wet but I was wondering if you dried it out a bit more if it would actually increase the plasticity like the Polar Ice does. Did they let you know which stain they are using for part of the black colour? 


"Polar Ice has extremely high plasticity (to properly pug it we must run it too soft). Others claim to be plastic, but they use the word in a relative sense (meaning a little less flabby than that other really flabby porcelain). Do not attempt to use Polar Ice if it is too soft (stiffen it before use to experience its full plasticity). To reduce the water content wedge it and flatten down onto a very clean plaster table or large bat (or you may be able to leave a lump under a cloth over night or longer).

The most prominent side effect of the plasticity is its stickiness, this body is extremely sticky. It will stick to your hands, to the table, to the cutting wire, anything that touches it. During trimming it will stick back to itself and tools. If you attach ware to the wheelhead with water to trim, it will stick fast there also. After trimming it balls up under your fingers if you attempt to round corners by pressing on them. However if you stiffen the body to optimal throwing stiffness, it will be much less sticky."

#124296 Recycling Clay - Turns Black And Stinky

Posted by Min on 25 March 2017 - 09:29 PM

White vinegar would also help with the smell.


Except it is a flocculant so it's going to have an effect on the clay. I use a titch of bleach, stir it up and let it sit for a few days, most of the bleachy smell is gone by then.

#124079 How Do You Make A Bird Bath?

Posted by Min on 20 March 2017 - 07:07 PM

Uneven drying, exacerbated by the diameter of the pot will cause that lift in the middle. Think you probably helped contribute to this by using your heat gun on the edge. Cover the rims and sides, top and bottom, with wax resist or snug plastic, leave the center of the pot exposed to the air. If only using plastic then put some tiny weights on the edge of it to keep it in place, no plastic or resist in the middle of the pot. Some people put a bag of dried beans in the center to force it to stay flat but you run the risk of cracking it with this method. When the pot is soft leather hard try putting it on a rack of some sort to allow air flow underneath as well as from the top to help even out the drying but keep the plastic on the edge until the middle is firm leather hard. If you use resist instead of plastic still dry it slowly.

#123641 Speckled Glazes

Posted by Min on 12 March 2017 - 03:13 PM

http://www.rabcospec...Crystals Store/


Specks and "crystals", I don't know anything about these but they look interesting.

#123638 Making Oven Safe Work..

Posted by Min on 12 March 2017 - 02:34 PM

I've a friend who makes those beer can chicken roasters and sells them to go on a barbecue. (insert head shake here)


Just making regular ovenware opens you up to problems. Doesn't matter what you tell the customer or print on a care instruction card, someone will do whatever the heck they want with it and blame the maker. "My grandmother has a casserole she has been using for years and....." I've had customers putting frozen puff pastry encrusted brie in a 450 oven and then complain the pot cracked. My sister in-law put frozen battered fish fillets on one of mine into a hot oven and complained when the pot broke. I don't make ovenware for sale anymore. We use it at home but for selling it I don't find it worth the hassle. I know lots of potters who do make and sell it with no problems but I make enough stuff without selling ovenware that I don't need the potential issues. (why is it that people who do the dumbest things are the most vocal afterwards at blaming others?)

#123563 Plates - Slump & Hump

Posted by Min on 10 March 2017 - 10:01 PM

Customer wanted the blu/blk combo, ours are just white. The scrap of paper with the weights/measurements is buried in my workshop somewhere, think it was 3lb12 I used for the dinner size. There is a foot, a lot of weight was trimmed away.

ps - I'm sure you have already thought of it but just in case, maybe measure the space in your dishwasher rack where you put plates plus your cupboard depth.



Attached Files

#123459 Need A White Matte Commercial Glaze Suggestion.

Posted by Min on 09 March 2017 - 10:22 AM

This goes from low fire to cone 10, the original recipe has bentonite in it, I replaced that with macaloid (and rebalanced). Works on greenware and bisque and is very white. Haven't tried doing what you are with wiping it down but I have used it on bisque with no problems on both red and white clay. If you want it even whiter you can add some zircopax to it but it's very white as is.



fish sauce slip (altered) 

 Minspar 200              27.50

 Grolleg Kaolin           40.80

 Pyrophyllite               8.30

 Silica                        17.00

 macaloid                   6.30



fish sauce slip original 

 Minspar 200              23.50

 Grolleg Kaolin           43.60

 Pyrophyllite                 7.80

 Bentonite                    9.50

 Silica                         15.60




edit: if you want to try this without going out and buying all the ingredients I can mail you a bit of the dry mix. pm me your address if you would like to.

#123381 Going To Buy Wheel And Kiln... What Do You Like?

Posted by Min on 07 March 2017 - 04:23 PM

I took Neil's advice from a few months ago and paid the extra for a Genesis controller on a recent kiln purchase (ConeArt). Haven't used it for long but so far I'm loving it, really user friendly.

#123372 What Does 100% Mixable Mean

Posted by Min on 07 March 2017 - 01:41 PM

Email the manufacturer for clarification but it sounds like you can combine it with other glazes that they make. 



 you should be able to trust the product details as Min described above especially if its a major manufacturer that is trying to protect itself from legal action.  https://en.wikipedia...ss_spectrometry


Except they always have a CYA line like "Tableware producers must test all finished ware to establish dinnerware status, due to possible variations in firing temperature and contamination.

#123338 Plates - Slump & Hump

Posted by Min on 06 March 2017 - 06:41 PM

If you ever want to try slump molds and making your own for plates or platters, you can make just the walls for a form. Thrown walls left round or altered to oval or whatever, since there is no base this is fairly quick, then bisque fired. Form put on a board or batt then slab construction for the pot. Also can put them on the wheel after slab done and add some throwing lines. Forms made fairly thick and low bisqued so they are quite porous. I was sloppy making the oval one, there should be an ever so slight indentation at the bottom of the wall, makes a mark on the slab to use as a glaze line.

Attached Files

#123313 Resist Over Glaze?

Posted by Min on 06 March 2017 - 11:55 AM

I picked up the product from Micheal's that Min and preeta suggested (liquid latex rubber). The stuff is smelly.


How do I apply it:

  1. Thick or thin?
  2. More than one coat?



Disposable brush or really soap it up first so you can clean it then just paint it on. One coat is good, if it's too thin it tears when when you lift it off. Maybe try on a shard first. Glaze then just lift an edge with a needle tool and it peels right off.

#123241 Resist Over Glaze?

Posted by Min on 04 March 2017 - 04:45 PM

Any type of latex (as in paint) or is there a formula designed for ceramics?


I've used this stuff from Michaels. (there are usually coupons online for 40-50% off).


(Don't know if latex paint would work, kinda think in that case resistance would be futile  ;)  )

#123167 Foodsafe Glaze Over Non-Foodsafe Glaze?

Posted by Min on 03 March 2017 - 11:46 AM

Pres "I usually do not worry about the Manganese speckling in functional ware, but should I?", not sure if this is a rhetorical question or not. It's the fumes coming out of the kiln from speckled clay with manganese that is the main concern.  

#123020 Glazing

Posted by Min on 28 February 2017 - 11:48 AM

arrggg, I only had 1 "like" to use today, totally agree Preeta and Chilly. 

My usual progression is test tiles, if it looks okay I run a crazing test. If it survives I use pinched slab test tubes, craze test again and if I'm concerned about shivering I use those to do that test. Then small pot, like the mini jug, then real pot like the bowl. (this set of tests is one I'm doing now for a low expansion clay and glaze, I'm thinking of doing a country farmhouse line of pots)

Attached File  wht glz test.jpg   50.11KB   0 downloads


#122945 Number Of Firings

Posted by Min on 26 February 2017 - 07:23 PM

A less precise way to do it would be by guesstimating it. Many glazes are between 70 and 80 grams of water to 100 grams of base glaze. 


To keep the math as simple as possible you could weigh out 180 grams of liquid glaze, of that a guesstimate would be that it contains 100 grams glaze, 80 grams water. So to add Neil’s amount of silicon carbide you would add 0.5 of a gram of silicon carbide to that. I would actually do a series of incremental increases to test a bunch of amounts. Start with adding 0.5 grams, dip a test tile, then add another 0.5 grams dip another test tile and keep going up by 0.5 until you get to about 4%. Could decrease the amount of base glaze to half that amount to save some waste glaze (and cut silicon carbide additions by 1/2 also). 



The weight of the water is not going to be spot on but it’s the ratio of wet glaze weight to silicon carbide that is going to be able to be replicated when you find a % that works. Just do a small test tile dip each time as the volume of base is going to be decreased with each subsequent dip and throwing the ratio off slightly.