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Member Since 13 Nov 2012
Offline Last Active Dec 26 2014 04:02 PM

Posts I've Made

In Topic: Real-Time Kiln Advice (Kiln Curently Firing)

28 August 2014 - 12:25 PM

I can try it again with the MRs (I think that's what John is suggesting?) but I don't think two B2s are the proper size for the kiln - that's how I ended up with these MR-100s in the first place.

In Topic: Real-Time Kiln Advice (Kiln Curently Firing)

28 August 2014 - 10:20 AM

In case that wasn't clear - here, let me make it even less clear.  This is my idea:




The lid would still sit on the metal frame, there would just otherwise be empty space over there on the right. 

Important to note:  I understand I need to build a proper kiln; no more of this conversion craziness.  But it appears we are moving - far, far away - next summer.  I want to stick with this one until that time, when I do build a proper kiln (from someone else's plans!) at our new home.

In Topic: Real-Time Kiln Advice (Kiln Curently Firing)

28 August 2014 - 10:03 AM

Howdy, guys.


I have just returned from a firing workshop at Watershed Center for the Ceramic Arts.  We fired two propane-fueled Venturi-burner downdraft kilns, one with salt.  Phew, did I never need that experience.  I have such a better understanding now, of so much.  Too much to mention.  But yes, I believe I had been focusing too much on turning up the burners instead of fiddling with the damper and waiting.  And now I understand what a reduction atmosphere looks like, when peering into the kiln.


Really, though, I don't think I have been doing that much wrong.  I really believe it's a burner issue.  Simply the heat coming off of them is enough tell me sum'n ain't raight.  I could grab hold of those burners at the workshop, even at the height of the firing.  I can't touch mine within seconds of ignition.


Here's what I would like to do:  Re-build my kiln so that it's a proper downdraft, sized to run on two B-2 burners, situated on either side of the chimney.  (As I already have one, and the high-pressure regulator, etc.)  It's 19 cu. ft. right now.  I'm guessing I'll need to make it about 2/3 of this size? (Unsure as of yet how to do the specific calculation; looking for a formula for BTU requirements with my 3" thick IFB walls.  Will figure it out though.) 

Having run through various scenarios (including turning the kiln on its side - which would make it front-loading - making the now-walls shorter, then building a sprung-arch top), I'm wondering if I couldn't just do this:

Leave it just how it is, but move the far wall (the one that now has burners) closer to the chimney, however many inches to get the cu. ft I need.  Does this make sense?  Just re-build that one wall, making the kiln more box-shaped than its current rectangle shape.  This would leave part of the roof and various metal parts of the kiln hanging out there are the end, but I think otherwise the concept will work?  I'd have a little 29"h x 27.5"w x Y"d flat-topped downdraft kiln.

Would love to hear comments on this, the latest of my hair-brained ideas.

In Topic: Real-Time Kiln Advice (Kiln Curently Firing)

25 June 2014 - 02:07 PM

Just in case anyone is hanging on the edge of their seats:


I spoke with numerous potters; no one was willing/able to help me.  So I gave it a go alone again.


The temperature stopped rising at 2175 (an additional two tanks and new regulator gave me 200 degrees!  Woo!) - I held there for quite a bit, then shut it down.  I reached anywhere from Cone 4 to Cone 6.  Still that same flame that just goes through one shelf and out the flue.  Still only one shelf with any reduction.  I used twice the amount of soda as I had in the past (2 kg in this 19 cu ft kiln), and there's really no evidence of having added more than before.  I believe the majority of it is going up the chimney (which, at that point, is less than 1" open at the damper).


In any event. This system, I believe, is fried. Done.  The amount of heat radiating from the two burners - and the gauges just behind them - is absurd.  I can't fathom the inter-workings to be still functioning properly.  (The heat in the burners is almost immediate upon lighting, as that blue flame is in the throat [but not to the orifice].)


Currently in the Frustrated stage, scheming about building a wood kiln.

In Topic: Real-Time Kiln Advice (Kiln Curently Firing)

19 June 2014 - 09:44 AM

Hooked up the four tanks, kept old regulator:  Same reading on pressure gauge - about 5.2.  (Marc expected 7-8.)


Replaced old regulator with new:  Pressure gauge reads 6.4 with one burner running, drops to 5.8 with both running.  


Marc has explained that the gauges should not drop when turning on an additional burner - and that it does do this, it indicates a volume issue.  He is trying to avoid switching me to high pressure, saying I've already spent too much money, and switching to high pressure would be much more.  But currently he has no ideas for me, other than using one regulator per burner.  But he wants me to fire it this way before trying the two-regulator option.


I'm currently trying to track down two retired ceramics professors who apparently live within 1/2 hour of me.  Because I'm not attempting this again alone.


I have to say, building a little wood-fired kiln (that Manabigama is so cute!) is looking better and better every day.  (With the given that I'd actually help fire someone else's before building my own.)