Marcia Selsor Posted July 23, 2016 Report Share Posted July 23, 2016 My friend who has the same kiln as mine is having problems reaching temperature. I am going to visit her next week to tweak her kiln.I thought some others here might be interested. The two 1/2 shelves are on half bricks tied together with about 5-7 inch posts for stability. Added a chimney after seeing the German and Scottish raku kilns. The burner is 1 1/2 inches away from the kiln wall to start with primary air disc barely open. By 1000 F I back it out a little more and increase the gas and air a little. The pressures is always a little below 5 psi.I was firing obvara today. three batches in 2.5 hours. I am beat and today is our anniversary. I will need (really bad) to freshen up! Link to comment Share on other sites More sharing options...
Dick White Posted July 23, 2016 Report Share Posted July 23, 2016 Why do you start with the primary air nearly closed? I have mine set at about 1/4" and leave it that way. I start with pressure at about 1.5psi, and bring it up to about 4psi by the end. Each firing takes about 30-40 minutes. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted July 23, 2016 Author Report Share Posted July 23, 2016 Dick, I have recently gotten several emails about firing raku kilns. As is true with just about all things in clay, there are many ways to do things. I start it that way to go slow and gentle, and turn it up around 1000.I also pull the burner farther away from the kiln relying on secondary air. Surprising what those little chimney parts do. I was firing a tumble stacked load of pots. I don't use much gas on my firings.I can tumble stack because there is no glaze. My firings take about the same. with time in between to remove each pot one at a time.I had 13 in this batch. Marcia Link to comment Share on other sites More sharing options...
Sofusryge Posted July 25, 2016 Report Share Posted July 25, 2016 Why the chimney? It must make it difficult to determine when to pull the wares from the kiln, or is it detachable? /Sofus Link to comment Share on other sites More sharing options...
Marcia Selsor Posted July 25, 2016 Author Report Share Posted July 25, 2016 I use a pyrometer. The chimney is detachable. I find it improves the draft especially if you have some breeze.. They are used widely in Europe. the photo below is from my workshop in Scotland with the Scottish Potters Guild last May. I have taught raku workshops in Spain where they also use a section of stove pipe for the chimney. A german manufacturer who makes raku kilns with chimneys and a very well designed stacking system of perforated shelves. Marcia Link to comment Share on other sites More sharing options...
Bob Coyle Posted July 26, 2016 Report Share Posted July 26, 2016 I had luck increasing the length of the chimney on one raku kiln that was not firing hot enough when using a ventui. I no longer try to fight city hall, and just use a blower. Works fine for a 55 gal barrel kiln with 1 inch Kaowool and one propane burner. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted July 31, 2016 Author Report Share Posted July 31, 2016 I don't have to fight the city. I have used my Marc Ward burners for about 20 years. They work really well. Marcia. Link to comment Share on other sites More sharing options...
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