"Sycronised Cracking" The failure

We all post our successful pot pictures, Lets get down and dirty guys and gals and show our total failures

Here is one for you. The whole kiln load was perfect except for this big ol bandit on the middle shelf. This is the only pot that was claimed by the kiln gods the rest was perfect

Just like loosing a tree, it always sucks when it happens. Any idea what caused it to crack?

Hello Andy,

Sorry for the bad text.
Better text still follows

regards
Peter

Been there;
Done That;

You need the T-shirt Andy!

Why is it always the biggest, nicest one worth the most money??

D.

I have always said that you produced crackin' pots

Tony

Hello Andy,

there are several kinds of cracks. This is a crack that occured during the firing process. But it might as well have happened during
the drying process. Cracks like this can also occur when the pot is put into the kiln.
One could write an entire book on all the mistakes that can happen.

regards
Peter

I can't see it very good in the picture , but it does look pretty wide at the top which makes me think it cracked on the way up in firing ( possiblyfinely cracked in bisque but with all the cracks I think it would have been noted) , BUT it doesn't look as if any glaze flowed into the cracks or rounded the edges, SO, I'm going to guess it cracked during cooling.
When mine crack it's usually during drying, or cooling.

D.

Dale

I have the t shirt my friend just don't like wearing it too often I agree with you though and think it is a cooling crack, and yes why does it have to the biggest and most expensive

Peter

There were no visual cracks in the drying process and it "rung like a bell" after the bisque firing. Thanks for the advise and information though I appreciate it.

Tony

Not funny

Rick

I think its in cooling. Possible draft from somewhere

Thanks for all your input guys

Regards

Andy

Andy,
Although its been a while since I have had any cracks in my pieces, I am sure with my new gas kiln I will be experiencing quite a few ( ), as can be expected with the learning curve. I lost probably two full (electric) kiln loads total in the early years, and it really taught me alot. The ruined piece forced me to reevaluate the pot, the processes I used to form it, and its firing.

I am guessing here, but it makes sense to me that this crack may have come from too big of a heat differential in the top portion of the pot. Whether this was from it cooling or heating too quick is what I would look into...

Your pots still rock mate!
Rob

Andy,



Was this dark spot intentional or did it happen during the firing?

If it happened during the firing, your problem could stem from contaminated clay. This looks like a burn out of some sort. I have seen this type of coloration from large iron particles burning out of a clay body.

Cheers,
Paul

Paul

I thought about this but I cant remember if I used oxides under the glaze or not. All that barium carbonate has addled my brain I am afraid

Regards

Andy

Looks like copper to me. I'm wondering if you had that same decoration on the other side that is cracked almost identical? If so, I'm still thinking it could be a prob from cooling speed where the copper is?
Andy, how thick are your kiln walls? 3" ?
Do you fire down your gas kiln?I think I remember you telling me once that you didn't. I ONLY fire down my electric kiln during inversion because it's fairly easy but I no longer high fire with the electric kiln, gas one only, and it's a PIA to fire-down my gas kiln so,
I have a technique I've used for several years to slow cooling on my gas kiln without firing down. I'll PM you as it takes some explanation.
Dale

Andy,
It is fun to see some pots that just went wrong-- we all have them. Here is one that turned into a big slump because I forgot to wad up the bottom I appreciate your honest and open approach to this site and enjoyed your new video. Here is one of my recent failures and was a commission that I have to start over But... it happens.

Opened the kiln a few moments ago and found this. Now to figure out why so I can try to prevent it from happening again.

AAARRRRRGGGHHHHHHHHHHH Hate it when that happens!!!

Rob

Thanks for showing your pot with warp factor 9. Like you said it happens to us all. I bet Kitoi is not best pleased at present

Regards to you both