Anyone Know Of Us Kiln Manufacturers That Do Anything Like This?

[mregecko]

http://www.northernkilns.com/cgi-bin/trolleyed_public.cgi?action=showprod_GASONWHEELS

 

Looks like a pretty nifty little downdraft kiln. I've been thinking about doing an Electric -> Downdraft Gas conversion project, but this is essentially one that's build specifically for the task... And it's on wheels, which would be great in a studio setting for me (move outdoors and monitor it for firing, then store it indoors).

 

Sadly, I'm in the US and they're in the UK. I'd love to find something similar in the states (I trust someone else's kiln-work much more than my lack of kiln modification experience).

 

Cheers,

-- Will

[High Bridge Pottery]

Wow, £4000. That seems a lot of money but it does look like a great kiln. Probably worth it.

[Wyndham]

That's a lot of $$$. Try to do it with an electric that's just a shell, I've seen some good youtube vids that work well.

Wyndham

[neilestrick]

You could build a much larger kiln yourself for $6700US, and I wouldn't trust those rubber wheels to last very long being that close to the kiln. One potential problem is the kiln shelf they're using to separate the flue from the kiln. It's going to warp over time, and when it does it will crack the bricks that it's mortised into. Used to happen all the time on the old Alpine kilns that used kiln shelves as bag walls. They warped and cracked the door jam they were set into. I switched them to a brick bag wall when I was manager there.

[mregecko]

It is definitely on the spendy side.... But still cheaper than front-loading stationary downdrafts (though smaller). For sure paying a premium.

 

And yes Wyndham, I'm still considering doing my own electric to gas conversion... I've watched all of Simon Leech's videos on it, and read every thread I could find about it here and on Clayart.

 

I also ordered Nils Lou's book (Art of Firing) and Mel Jacobson's book (21st Century Kilns) and plan to devour them.

 

But, at the end of the day, I'm still 100% new to working on kilns. Never cut a brick, have no tools for it, etc... If I had to pay a premium for something like this, it might be worth it to me.

[mregecko]

Neil, yes the inflated rubber wheels DID seem odd to me... I'd much rather have a set of hard castors or something shielded from the heat somehow.

 

And I'm not worried about size. Smaller is actually probably better for me in a city studio (to a point). But at $6700 you could definitely be looking at 12-ish cu ft front-loaders... If I could house them.

 

And that's a good note about the chimney's bagwall too. I was curious about that. We've all seen kiln shelves warp over time, but I thought it was more from gravity while they are hot (a sagging effect). I didn't know they'd warp in a vertical position. Good to know!

[oldlady]

mregecko, call Ward burners and talk to an expert.  also Steve Branfman who was going to come down here and convert an old Paragon with the wiring stripped out until I found that the local LP gas co would only give me a 1000 gallon tank for any kiln.  who can afford that?????  I saw a video once of a wood firing done in a series of old ten sided top loaders that ran up a hill on their sides.  shelves were resting on the interior bricks without any posts.  a modern anagama encased in metal but fired with wood.  I got to that video from web links. i originally  was looking at the website of Ayumi in New York state and just wandered around.

 

(a welder could rig up a great base for wheels under whatever you design.)

[neilestrick]

Kiln shelves do warp from gravity and weight, but they also warp from uneven heating. The hot side expands more than the cold side, causing a warp in the shelf. Over time they don't go back to totally straight when they cool.

[Mark C.]

That kiln is a very small one with only 1 burner which will add to its unevenness for firing. Single burner kilns are by their very nature more uneven that two or 4 burner models. One could make that puppy easy with an old electric but be prepared for all the woes you read about on these.

Mark

[neilestrick]

That kiln is a very small one with only 1 burner which will add to its unevenness for firing. Single burner kilns are by their very nature more uneven that two or 4 burner models. One could make that puppy easy with an old electric but be prepared for all the woes you read about on these.

Mark

 

I've built and fired a couple of one burner models without any problems, however they were all power burners. In my opinion, venturi burners don't work well on these little kilns, and the round design is not great, either. The ones I built were rectangular, with a firebox one one side. I think these electric-to-gas style kilns would work much better with oval kilns, so you could put in a firebox at one end.

[Mark C.]

 

That kiln is a very small one with only 1 burner which will add to its unevenness for firing. Single burner kilns are by their very nature more uneven that two or 4 burner models. One could make that puppy easy with an old electric but be prepared for all the woes you read about on these.

Mark

 

I've built and fired a couple of one burner models without any problems, however they were all power burners. In my opinion, venturi burners don't work well on these little kilns, and the round design is not great, either. The ones I built were rectangular, with a firebox one one side. I think these electric-to-gas style kilns would work much better with oval kilns, so you could put in a firebox at one end.

 

I agree with you on that power burner  issue on a these small kilns as it puts out more heat and evens things out oin a small space.

Mark

[Guest JBaymore]

I don't think that it is so much that it puts out more heat energy.... but that it does a better job of mixing in the kiln chamber.  Induces turbuklence, and can supply 100 primary if needed.  Flame stratification on  the cheapie venturi burners that those hex conversion kilns or even the commercial hex gas kilns tend to use are SO reliant on secondary air.  And that secondary needs space and time to actually mix into the flow to burn. And it doesn't have it before it contacts pots... or is out the flue at the top.  Uneven temperature, uneven oxidation/reduction, and inefficent use of gas heat energy.

 

best,

 

................john

[neilestrick]

Flame stratification on  the cheapie venturi burners that those hex conversion kilns or even the commercial hex gas kilns tend to use are SO reliant on secondary air. 

 

And yet those kilns have little to no chimney height to actually create the draw needed to provide that secondary air. Power burners are perfect for kilns with no chimney! For the price of the 2 to 4 venturi burners they typically use on the little round kilns, they could build a single power burner with the same or greater output. The real cost of burner systems is in the safety equipment- solenoids, flame sensors, etc.- not the burner itself.

 

The other great thing about power burners is that you can drastically change the orifice size without messing up the burner. So if you don't have enough power, you can fix it by increasing the orifice size (as long as you have enough gas volume coming in, of course). And if you find you need more air, you can put on a larger blower.

 

I think that many of the folks who convert the round electrics into gas think that because the round raku gas kilns work well, it should also work for a cone 10 reduction kiln. But the truth is that any crappy burner setup can get a raku kiln to temperature. 1850F degrees is easy. But as you get into higher temperatures the lack of insulation in those kilns becomes a real issue, as does the uneven temperature and atmosphere.

[Guest JBaymore]

Well said, Neil.  Dead on.

 

best,

 

...............john

[mregecko]

I have so many questions to ask about burners and air supply! But am going to wait until I get in the kiln books I ordered (Monday). Hopefully I can answer some or all of them myself.

[timbo_heff]

There is also the Olympic Torchbearer:

It is an updraft but a really cheap way to have a brand new cone 10 gas kiln at  home

[neilestrick]

There is also the Olympic Torchbearer:

It is an updraft but a really cheap way to have a brand new cone 10 gas kiln at  home

 

Those tend to have the same problems- uneven firings and poor consistency. I do know a couple of people who use them fairly successfully, but there's a huge learning curve from what they tell me.