Pre Heat Greenware To Dry Out Days Before Firing

[Jenn Candiano]

It is currently 27 degrees in NY and I can not tell if my green ware is completely dry. I loaded my kiln today for a firing in 2 days and I am thinking of preheating it for 2 hours to dry it out. Is this possible and worth it? 

I am also trying to avoid an extra 2 hours in firing. 

 

 

[ayjay]

It is currently 27 degrees in NY and I can not tell if my green ware is completely dry. I loaded my kiln today for a firing in 2 days and I am thinking of preheating it for 2 hours to dry it out. Is this possible and worth it? 

I am also trying to avoid an extra 2 hours in firing. 

Yes, it's known as candling.

 

It's very worthwhile if you don't think your greenware is dry. I usually candle for a while even if I think everything is dry - keep the temperature below the boiling point of water.  (100°C or 212°F)

 

Why do you want to avoid an extra 2 hours firing if you're not planning to fire for another two days? 

[Chris Campbell]

If you are not firing for two days then take one piece into the house and let it come to room temp ... then you can easily test it for dryness by holding it to your cheek ... see how cold it feels. Very damp and cold ... or just sort of ... or not at all.

That said, it never hurts to candle a load you care about.

[Mark C.]

Dry the pots any way you want only if you care about them?

I suggest candling -for me its worth it for me as everything I make has some value down the line if it makes it thru the process.

[Denice]

I  mostly hand build so I often candle overnight,  my time making them is worth a lot more than what little extra electricity I use.     Denice

[oddartist]

I always candle for a few hours no matter how dry things seem and I'm never had a piece explode.

[Chris Campbell]

Just how off the chart wrong am I??

In all my years in pottery (30) I've candled a load under ten times. I load when things are dry and fire. No problems.

It's the way I was taught ... is there anyone else who does this?

[Stephen]

sounds right if possible. I have been trying to build inventory between shows every two weeks and this has meant tight turn around to keep my shelves somewhat stocked. My main seller is mugs so they are getting depleted between shows and I need to glaze and take instead leaving to dry while I'm gone.

 

I am working hard to get where you are though as that's the way we had always done it in the past and like you we had no issues when just letting everything dry properly. I will say I have been throwing one day, handling the next morning and letting them sit all day and then candling that night for 10 hours and then slow bisque and have had zero issues. This has also worked fine for other forms including platters so it is working for me in this tight situation, at least so far.

 

Now I have a load in right now that candled last night so we will see if my streak of good fortune continues. 

[Chris Campbell]

That sounds right if you are trying for fast turn around on utilitarian wares. My work was mostly even sided thin objects so that could be why I could do it.

[ayjay]

Just how off the chart wrong am I??

In all my years in pottery (30) I've candled a load under ten times. I load when things are dry and fire. No problems.

It's the way I was taught ... is there anyone else who does this?

 

you can easily test it for dryness by holding it to your cheek .

 

When I hold a piece to my cheek to test for dryness I encounter my beard, I'm guessing that you don't have that problem.

 

It's just belt and braces for me Chris, I already know it's dry: it costs me 1 kw of electrickery for my usual candling routine, it's nothing - 12 pence, and the kiln is then preheated so my bisgue fire costs proportionately less.

 

In my 50 years as a Carpenter, nothing has ever collapsed, fallen off the wall, come apart or failed in any other way because of poor fixings etc - my  belt and braces mentality is the reason for that and it works for pots too.