JENS MALMGREN I create, that is my hobby.

Exploration into smoke and fire



Today it was time for the raku burn sessions. No rain was expected until the afternoon and it was wind still so this was a nice day for raku firing. I planned three sessions. For each session the kiln is first loaded. Then it is brought up to a temperature of 920 degrees so that the glazing would start melting; the kiln is opened and the goods are moved over to pots filled with sawdust and the lids are closed. When a piece is taken out from the kiln the glazing is cracking and when the item is put in a pot with sawdust all parts not covered with glazing and the cracks is turned black because of the smoke and a shortage of oxygen.

10:00 (10AM) Moved the rests of the coal from the biscuit burn into the fireplace, cleaned the bottom of the oven.

Started to load the oven in such way it should be easy to take out things while it was still burning.

It was also important to let the items stand in such way the heat airflow would pass the items in an optimal way. I checked the glazing that there was no risk for dripping on the oven plate. All these choices to make can be “suffocating”, if I do this or that what happens then?

10:35 (10.35 AM), Started the fire outside the opening of the kiln.
10:40 (10:40 AM), I shoveled in the fire into the opening of the kiln.
11:00 (11 AM) 497 degrees Celsius.
11:06 (11:06 AM) 600 degrees Celsius.

Preparing pots with sawdust.

11:15 (11:15 AM) 700 degrees Celsius.

The raku tong is also perfect for administrating a fire.

11:45 (11:45 AM) 942 degrees Celsius. Too hot!
11:47 (11:42 AM) 902 degrees Celsius. Too cool.
11:50 (11:50 AM) 925 degrees Celsius. Good temperature.
11:55 (11:55 AM) 930 degrees Celsius. Too hot!
11:58 (11:58 AM) 903 degrees Celsius. Too cool. Now it is time to open the kiln and put the items in the pots.

12:05 (12:05 PM) 406 degrees Celsius. All items in the pots.

Secret pots. How did it go?

Between the first and the second I decided to apply more glazing to the items for the second burn. Later it should turn out that this was a really bad decision. The glazing got to thick and started to boil and bubble, also a combination with that it got to hot maybe.

Next burn.
13:25 (1:25 PM) 184 degrees Celsius.
13:30 (1:30 PM) Rain. 675 degrees Celsius.
13:35 (1:35 PM) No rain. 705 degrees Celsius.
13:45 (1:45 PM) 780 degrees Celsius.
14:03 (2:02 PM) 921 degrees Celsius.
Managed to hold the kiln between 920 and 940 degrees Celsius during 10 minuts.
14:04 (2:04 PM) Now we take out the goods from the kiln and put it in the pots.
14:08 (2:08 PM) Everything in the pots.
14:18 (2:18 PM) How did it go?

Final burn
14:47 (2:47 PM) Kiln loaded and closed.
14:50 (2:50 PM) 250 degrees Celsius.
14:52 (2:52 PM) 740 degrees Celsius.
14:54 (2:54 PM) 800 degrees Celsius.
14:55 (2:55 PM) 850 degrees Celsius.
15:10 (3:10 PM) Everything in the pots. 15:20 (3:20 PM) How did it go?

16:00 It started to rain heavily.

Here is a sample of a garlic sculpture before raku.

Here after raku burn.

Tried chemical cleaning. Sprayed the items with K2r.

I also tried sanding the items and this gave a nice result. The glazing shiny surface is gone but the cracks are visible and I got to terms with the result. I am excited how nice experience this was. Wow!

In future posts I will display the results of successful items of the first burn.


I was born 1967 in Stockholm, Sweden. I grew up in the small village Vågdalen in north Sweden. 1989 I moved to Umeå to study Computer Science at University of Umeå. 1995 I moved to the Netherlands where I live in Almere not far from Amsterdam.

Here on this site I let you see my creations.

I create, that is my hobby.