Dark rutile v Rutile

[Evelyne Pensa]

I found a recipe for a yellow cone6/7 oxydation glaze as follow:

Schefflin Yellow

Gerstley Borate 50
EPK                 15
Flint                  35
Total               100

Dark Rutile 15

I'm wondering what the difference is between rutile and dark rutile ? I don't know if it is because I live in France but I've never heard about dark rutile ..having saud that , I don't have a very long experience in ceramics !!!

Evelyne

 

[June Perry]

I believe the dark rutile has a higher iron content.

 

If you're looking for a yellow I have some cone 6 and cone 10 yellow recipes on my web page.

 

June,

http://www.shambhalapottery.com

http://www.shambhalapottery.blogspot.com

 

[Evelyne Pensa]

Thank you  for your answer ; I'll have a look at your web site and will look for information on dark rutile in France ...I really love rutile in glazes !!!

Evelyne

PS : my blog (in French, sorry ...) :

http://apipoterie.wordpress.com/

 

[Peter Jankowski]

Hi Evelyne,

I've been browsing this site for quite a while and haven't as yet posted but your question was a concern of mine also a few weeks ago.

I phoned US Pigments regarding the same recipe and was told that the two rutiles are listed as "Light Rutile" and "Rutile". The latter being considered the "Dark" one without specifically being labled as such..

[Evelyne Pensa]

Thanks for answering Peter !

The only problem is that I live in france so the it's not quite the same ....I'll check but I think here we only fine "rutile" ..

[George Lewter]

FYI Rutile is an impure form of titanium dioxide (white colorant or opacifier) with around 10% iron and other metal oxides in minor amounts.

"Rutile is available in light calcined ceramic grade powder (very fine particle size), dark uncalcined powder, and granular form. Either grade of powder can be ground very fine (e.g. 325 mesh). In glazes it is generally better to use the ceramic grade since the decomposition of raw rutile during firing can be a source of glaze imperfections like pinholing and bubbles (even larger amounts of the ceramic grade, e.g. 8%, can also cause problems)." from Ceramic materials database at digitalfire. 

[Michele Sadler]

Hi Evelyne, I am practicing as well ... what I have learned is that many recipes say rutile ... but do not tell me what kind. So when I picked up my next batch of supplies I got all they had. They had 3 kinds, dark, light and granular. when I am testing my glazes, I make enough to do three tiles to see what the results are... and they very alot. The granular makes amazing speckles. Michele

[Evelyne Pensa]

Hi !

I still don't know what type I'm getting ..in France where I live they seem to sell just "rutile " !! it is not granular but as for dark or light I can't compare ! 

I do have some problems with pinholing ...I have made a new batch of my glaze with a bit less rutile I'll see if it makes a difference .

I really love the effect of rutile in glazes ! I'd like to order the 3 types of rutile from USA to check the difference but the quantities minimum to buy are already too heavy , postage is too expensive ! so i'll just to make do with what I've got here I suppose !

Thank you for your answer Michele . Regards to all from France !

[June Perry]

Evelyn, check with your supplier. I suspect that if they only sell one type, that it's ceramic grade which would be the darker rutile. Usually light rutile is marketed as light I've never seen rutile marketed as dark, so maybe the person posting or publishing the recipe used the dark reference to distinguish it from the light.

Rutile, zinc and high whiting as well as bisque temperatures and firing conditions etc. all have the possibility of causing pinholing, so you may have to explore all of those conditions to try and eliminate the problem.

June

[Donna Kat]

Where are you in France?  I am on the border in San Sebastian Spain.  Love the pictures on your blog and wish I read French. 

Any type of rutile will give you a yellow glaze in the following recipe as will just Titanium Dioxide.  The dark rutile will give a more harsh deeper yellow (more harse to me that is).  I made up this recipe with different frits and they all gave a nice yellow glaze but only the 3110 gives a pretty frosted yellow.  Without the rutile it is a light cream yellow.  With rutile it is a medium to dark yellow depending on the rutile used.  http://digitalfire.com/4sight/material/rutile_1204.html

Butterscotch
3110  Frit	20
Dolomite	20
Spodumene - Foote	20
Ball Clay - Old Mine #4	20
Silica	20
Titanium Dioxide	10
Rutile	6

[Evelyne Pensa]

Thanks a lot Donna !

I'm a bit far from you ..I live near Valence (south if Lyon) in a small village !

I told myself that I should do a bilingual (French/English) blog ..but I tend to forget !

I also have a facebook page .

I'll try the recipe you gave me when I come back next week !

Do you have a blog or a website ?

[Michele Sadler]

Evelyne,

  Good luck with your experiment, I too am doing some testing this weekend and will try to get some pics as I am testing the rutile "rituale" of all 3 types to see what one works best on some new recipes...

  I too have a French heritage but cant find out from where in France, we have been trying to trace it back but get stuck up in Canada where the church burnt down that held all the local records... :o(

  Have a great weekend and have fun testing ...  

[Norm Stuart]

As George Lewter said, "Rutile is available in light calcined ceramic grade powder (very fine particle size), dark uncalcined powder, and granular form. Either grade of powder can be ground very fine (e.g. 325 mesh). In glazes it is generally better to use the ceramic grade since the decomposition of raw rutile during firing can be a source of glaze imperfections like pinholing and bubbles (even larger amounts of the ceramic grade, e.g. 8%, can also cause problems)."

http://digitalfire.com/4sight/material/rutile_1204.html

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http://translate.google.com/translate?sl=auto&tl=fr&js=n&am...

Comme l'a dit George Lewter,Rutile est disponible en poudre légère calciné céramique grade (granulométrie très fine), poudre non calcinée sombre, et sous forme de granulés. Soit la nuance de poudre peut être broyé très fin (par exemple, 325 mesh). En émaux, il est généralement préférable d'utiliser le grade céramique depuis la décomposition de rutile brut pendant la cuisson peut être une source de givre imperfections comme des piqûres et des bulles (même des quantités plus importantes de la qualité céramique, par exemple 8%, peuvent également causer des problèmes).