Low fire liner glazes in raku

[Retxy]

Hi smart ceramic friends,

Can I get some input as to why liner glazes that are low fire are not used inside Raku pottery? Or is it that they are and I just am behind the ball. I would be interested in making pieces with liner glaze inside in the hopes of potentially keeping the bad stuff on the outside and a good stuff on the inside. Is this a possibility or am I missing something?

 

Thank you so much in advance

D

[Mark C.]

Raku is porious and very low fire. Most low fire(cone 06)  is above raku temps and raku is very much not a controlled process in terms of exact temps

Back in the lead raku days it was a different story in terms of low temp melts. No more lead .

 

[Retxy]

Thank you so much Mark in theory if one had a thermocouple and the will could liner glaze be used? I have come across some raccoon glazes that go all the way up to 1950 in order to properly work and I think it would be interesting to at least try a liner. maybe to answer my own question this is a test and see if it works situation!!!

[Rae Reich]

Are you hoping to have a liner glaze that is watertight ?
Generally, the stresses of the Raku process between an interior glaze and partially or unglazed exterior result in faults that impair the integrity of the pot. I would expect some crazing if the liner is applied thickly, depending on glaze fit at raku temperature.

Test, test, test.

 

Edited February 19, 2023 by Rae Reich

[neilestrick]

Most any glaze is going to craze from the thermal shock of the raku process, which means it won't be watertight or suitable for food.

[oldlady]

the pot will leak, period.

[Mark C.]

I was given a raku mug from Mexico a few years ago and it was touted to be fluid holding. And also sold to restaurants in that village in mexico . It appeared to have a liner glaze as well. I filled it with water put on the counter within a few minutes the outside became wet looking up to the fluid level. Just think about a glass of milk seeping in those pores-yuk. Raku is not for funtional work. So if you want the good stuff on the inside raku is not the pathway forward.

 

[Babs]

I seem to remember somewhere soaking pots with milk was the go.

Anyone remember?

Mid european ....

[High Bridge Pottery]

22 minutes ago, Babs said:

I seem to remember somewhere soaking pots with milk was the go.

Anyone remember?

Mid european ....

Are you thinking obava firing Babs? 

"Obvara is a 12th Century raku firing technique using only fermented flour, water, milk or beer. It was developed in the Baltic region of Eastern Europe (Latvia, Lithuania, Belarus) when a vessel was probably standing by a fire and then rolled into a slops bucket containing fermented waste."

Edited February 20, 2023 by High Bridge Pottery

[Min]

4 hours ago, Babs said:

I seem to remember somewhere soaking pots with milk was the go.

 

[Babs]

Yep that is what was coming to mind.

Thanks you guys.

[Rae Reich]

My Granny, (b.1888, d.1976) grew up in Utah and described to skeptical new potter me how the native potters there glazed their ware with milk! Sorry I doubted you, Granny!

[Babs]

Prob after a few coats would seal it :-)

Yoghurt smeared on terracotta encourages an aged patina, they say.

[Retxy]

Thank you all so much! Im trying to give my afolescent nephews a raku fire show and reallly want them to have something safe they can use daily from the experience like a mug. I see some horsehair raku makers on etsy with lined vessels and thoight maybe its stoneware which is raku'd first then fired to cone with liner after but the description says they are raku'd last. Ugh my poor brains!!  Thanks again!!

 

[Retxy]

 

Aha!! Testing...

[Callie Beller Diesel]

You can make functional pieces that are raku if you clarify your definition of functional to exclude food/liquid use. 

My teenage son is nerdy as heck, so if I was a thinking about something that he or his friends would like, I’d think about dice rolling towers, or stands/containers for video game controllers or game cartridges or USB sticks. Maybe an analog phone speaker that has room for the charging cord.

If your nephews aren’t into all things video/table top/card games, the phone speaker idea would still probably work, but as long as you find something related to their existing interests, that’s going to increase the odds of them using it. 

[Retxy]

On 2/22/2023 at 7:50 PM, Callie Beller Diesel said:

You can make functional pieces that are raku if you clarify your definition of functional to exclude food/liquid use. 

My teenage son is nerdy as heck, so if I was a thinking about something that he or his friends would like, I’d think about dice rolling towers, or stands/containers for video game controllers or game cartridges or USB sticks. Maybe an analog phone speaker that has room for the charging cord.

If your nephews aren’t into all things video/table top/card games, the phone speaker idea would still probably work, but as long as you find something related to their existing interests, that’s going to increase the odds of them using it. 

Thank you so much Callie! One of my nephews is into bonsai, so that's easy but will still require some waterproofing. Made of Australia had a liquid quartz which they claim will make raku waterproof but I can't justify the cost and also can't really see the difference between their liquid silica and plain ole waterglass/ sodium silicate. I'm going to try some of that and see. Thanks for the awesome ideas!!