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Porridge
01-06-2010, 07:55 PM
Whilst trying to get to grips with the whole Raku process I have come across Naked Raku.

What I cannot understand is why the bisque fired pot needs dipping in slip and then when dry, glaze, if both layers peel off later?

Why wont the process work with just a coating of slip? Why do you need to add glaze as well if it doesnt come into contact with the clay body?

Decima
01-06-2010, 11:03 PM
Hiya,

The way that naked raku works is that when in the reduction chamber the smoke permeates through the outer coating to leave carbon marks on the clay vessel. You can leave this to chance, or you can create your own pattern through the slip and glaze before firing. The reason for the glaze is to keep the slip on the pot so that it does not fall off in the kiln, if this happened you would get great big patches of black after reduction instead of beautiful delicate grey lines. The glaze is also an indication of when the vessel is ready to come out of the kiln. The vessels should be burnished before bisque firing for naked raku to be successful.

Hope this makes sense :confused:

Eileen

Porridge
02-06-2010, 09:12 AM
Hi Eileen,

That makes sense.

I have some stoneware slip suitable for casting etc, would that be suitable? I also have some glaze that I bought rather than mixed myself which I am not too keen on. On the basis that the glaze just keeps the slip from falling off and doesnt act as a glaze on the clay body I could use that rather than see it stay on the shelf for years to come?

When I do a normal raku firing I am starting to see that by letting the glaze surface bubble then smooth then gloss over it is time to take out the kiln. This is usually around 970oC which I hold for 10-15 mins.

What are you looking for on the galze surface in naked raku that tells you it is ready and what temp would you sugget this occurs at?

Thanks for your advice.

Pete

Decima
02-06-2010, 10:27 AM
Hi Pete,

I don't think that you could use the slip and glaze that you already have, as they need to be incompatable with each other and the body of the vessel otherwise everything would stick to everything else and not fall off at the end.

Here are the recipes I use and tend to have good results with.

Slip China Clay 3 parts
Flint 2 parts

Glaze High Alk Frit 8.5
China Clay 1.5

I always make large quantities of the above as I find that dipping gives the better results.


Take the pieces out of the kiln when they have gone glossy, there is no benefit to soaking them for this technique.

Hope all goes well

Eileen

Porridge
02-06-2010, 10:21 PM
Hello Eileen,

Thanks for the info, what volume of water do you mix in with the slip and glaze ingredients?

I cant wait to have a go at Naked raku.

Best wishes

Pete

Decima
02-06-2010, 10:33 PM
Hi Pete,

For the glaze I would use the normal 100ml to 100g rule. But the slip is a little more difficult your looking for something that is a double cream consistency.

Naked raku is great, but it can be frustrating at times, especially when you are trying to get those last little bits of glaze and slip off at the end.

Have fun

Eileen

jevpots
18-03-2011, 04:43 PM
Hi Pete - How did you get on with the naked? A little bit more info. You can do naked with just a slip - this is usually known as 'one-step'. The method with slip and glaze as 'two-step'. The slip for one-step is very thick - like thick yoghurt - and is usually made up with a fireclay so that it doesn't start sintering at the temps used for raku. The slip dries and cracks during the firing and the smoke then permeates the cracks. It is often difficult to keep this slip on the pot.

The two-step process gives much more control and uses the slip as described by Eileen to stop the glaze sticking to the pot (rather than the glaze used to stop the slip falling off - the two step slip doesn't fall off and can be used on its own for naked to give grey tones if you want to do some francy shading) Its the glaze which really acts as the barrier to the smoke and much more effectively than the slip.So that where the glaze remians intact the pot remains white (or whatever the colour of the underlying clay is). Where the glaze cracks, spots, or is sgraffitod you will get black lines.

Hope its working for you.
jev - jevceramics.co.uk

toppotter
19-03-2011, 10:33 AM
Hi Jev, I think its for the following reason; if there wasn't a glaze coating when the raku piece is reduced in wood shavings etc the smoke would penetrate throught the slip to the body below.

regards Robin

Duke of Burl
19-03-2011, 11:31 AM
Hmmm seems I got confused with naked reiki! Oh well ... the upside is at least I understand how to glaze that pot I have lying around now! ... lol who knew pottery could be so racy!

Stephanienone
09-05-2011, 05:54 PM
Hi,
I did the one step naked raku method and I am struggling to get the slip off of my clay now that they have been fired. I have tried scrapping with a wooden tool but it doesnt work! I even tried soaking my pots in water in the hopes that this would help the slip come off but it didnt work (and I ended up breaking a piece). I was just wondering if anyone had any suggestions as to how to get this slip off!
Thanks
Stephanie

Porridge
22-05-2011, 08:50 PM
Hello Stephanie,

Was the slip the same as the clay body? what temperature did you take the kiln to? My last naked raku firing was the 2 step approach, which I took up to 900, or when the surface got very bumpy. The slip/glaze came off quite easily, mostly at the point I dunked the pieces in water.

How burnished was your pot? I noticed that on a pot which was bunished smoothly at the top and fairly rough at the bottom, it came off the smooth section alot easier.

Pete

jevpots
31-05-2011, 08:32 PM
Hi Stephanie - Sounds like you need to adjust your slip recipe so that it is more refractory or reduce the temperature you fire to. With one-step, after the initial slow firing to about 200 deg C, you only need to fire to about 750C to make the pot hot enought to take on the smoke. I'm wondering if you fired so high that the slip has now become part of the pot. One-step slip usually has a fair bit of fireclay in it si is fairly refractory and usually comes off too easily rather than being obstinate like yours. If water soaking hasn't helped its probably a lost cause.

jev

terrorcotta
01-09-2011, 08:39 PM
I would advise the wearing of asbestos underware, if nothing else, when attempting Naked Raku! :eek:

:behindsofa:

Terrorcotta :D

Jim Frank
15-10-2011, 11:32 AM
In the 16th century, Sen Rikyu, the Japanese tea master, was involved with the construction of the Jurakudai and had a tile-maker, named Chōjirō, produce hand-moulded tea bowls for use in the wabi-styled tea ceremony that was Rikyū's ideal. The resulting tea bowls made by Chōjirō were initially referred to as "ima-yaki" ("contemporary ware") and were also distinguished as Juraku-yaki, from the red clay (Juraku) that they employed. Hideyoshi presented Jokei, Chōjirō's son, with a seal that bore the Chinese character for raku. Raku then became the name of the family that produced the wares.