Seaweed glaze running and blistering

[annie92499]

I am really new to pottery, and so far having a blast. I am using Amaco clays, and Amaco Potter's Choice glazes (to scared to experiment yet!). Everything has gone beautifully and I've been delighted with their glazes, but I'm having reoccuring problems with their Seaweed glaze. It runs really badly, and usually blisters all over the outside. None of the other glazes do this, they couldn't be more picture perfect.

 

I've only used Amaco clays that they recommend for the PC glazes, Buff, Brown, and Speckled, and it has run horribly on all 3. On a bowl the sides will be thin and translucent and the bottom will be beautiful green. The top almost doesn't have glaze on it, it's all run to the bottom. And the outside it usually blistered badly and I'm lucky if it's not stuck to my shelf (it happened on the 1st piece, now I don't let it get closer then 1-2" from the bottom and it will run to the bottom but not enough to stick to the shelf).

 

I asked a local potter I know who uses PC glazes and she said, "That's just Seaweed, it ruins shelves, don't use it."

 

I love the Seaweed though! It's gorgeous! And I really want to layer it, but I'm scared to ruin my shelves. I saw other people on here use it, do you do anything to it? I have followed the directions to the letter and it's gone crazy every time. Surely I must be doing something wrong because they could not sell it and make money if it just ruined everybodies shelves!

 

I would really appreciate your advice on where I am going wrong with my Seaweed.

[weeble]

What cone are you firing to? It sounds like your kiln is firing a bit hot. Some glazes react ok to extra heat, some don't. Bubbling and running are a good indicator that its too hot.

[Lucille Oka]

The test I did with PC 42 was rather nice. I applied the glaze to a mature cone 04 bisque, #65 Porcelain and layered it on 2 coats of PC 59, on a textured, sprigged Sake cup. I put three coats on the interior and two coats on the exterior. I wanted to see just how much it flowed but I didn't want to risk a shelf just in case it flowed too much. I also glazed it alone on a flat textured tile which came out beautifully just like the Amaco flat tile. I fired the glaze to witness cone 6 no bloating of any kind it is just lovely. To what temperatures did you fire PC 42?