Real-Time Kiln Advice (Kiln Curently Firing)

[Kristin_Gail]

I'm sorry - it isn't reducing any longer. Fingers numb, difficult to type. But there was a soft 4" flame coming out a large soda port at the top-ish of the side of the kiln when it was reducing. I believe I was not moving the damper in small enough increments, or waiting long enough between movements, in previous firings. I found that I could just barely get that flame coming from the port if I had the damper open 1.75" with all three primary airs (counting the pilot, which I would *love* to turn off if I could) open about a pencil's thickness.

 

It was going at about 100/hr before I started reducing, and about the same throughout (I reduced from about 1625 to 1850). It went faster for a bit afterward, but now it's slowing way down. 80/hr. At 1900 - this is the temp where it always seems to *almost* stall.

[Kristin_Gail]

Besides the regulator covered in condensation, the tanks are now freezing up. Assuming they were completely filled 4 hours ago, I've used more than 1/4 of one and more than 1/3 of the other. Strange they're going at different rates - never seen that before. Wondering if one wasn't filled properly.

 

Canada in late May = damn cold.

[Guest JBaymore]

Your gauge for adjusting the reduction in the kiln would be a BOTTOM spy port at almost the exact level of the exit flue.  You want to adjust the damper (and burner settings) so that when you pull out the plug there, as the plug comes out of the hole, a little tail of flame follows it.... but does not remain coming out there.  Technicall what you want is the balance such that the chamber pressure (under flow) at the flue level in the chamber is neutral to the atmospheric surrounding the kiln.  No flame is backing out.... no air is getting sucked in.  In that case the entire chamber will be filled with the products of combustion.... and getting somewhat equal reduction (not to mention equal heat transfer).

 

From what you just said (and what is actually going on is not all that clear to me) I am guessing that at the moment your "stall" in this range is because you are in oxidizing conditions now........ and you are pulling un-necessary cold air thru the kiln.  But that is a total guess.

 

So are you saying that the chamber atmosphere is basically totally "clear" except where you see a longer yellowish flame getting "sucked" over the bag wall in thru only one portion of the chamber?

 

best,

 

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

[Guest JBaymore]

Exterior condensation is not an issue.  Normal.  My 500 gallon tank when I am firing my 40 cubic foot kiln gets that sometimes.

 

Are the tanks actually freezing up.... or are you just seeing condensation freezing on the exterior surface?  What is the main tank pressure showing on the guage (before the primary regulator)?   (Hopefully you hjave one.)  And how does that compare to what it ususally reads?

 

best,

 

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

[Kristin_Gail]

Yes, I think that's what I'm saying, about the atmosphere of the kiln being clear and the yellow/orange flame is coming through. Hopefully you could see the video?

 

Earlier today, when the tanks were down to 25% full, the water column gauge only went to 4 with the levers completely open. (usually it's just above 5.) That's what I called freezing. Now the tanks are frozen/frosted on the section that still contains propane. But the gauge is still reading 5. Besides the water column gauge just behind the burner, there are no other gauges. There's a hose from each tank, they both go into the not-really-adjustable regulator, then out they split again into the two hoses going to the burners.

[Kristin_Gail]

Changing primary air dials, damper, passive damper, in various directions, waiting for what seems like a long time in between adjustments, leaves me with either falling temperatures or slowly rising to a stop at 1970.

 

In two previous firings, I've reached this spot and put in a bit of wood, which got me to cone 6. But I understand that's not what this kiln was meant to do. And I need to learn how to fire it properly.

 

We've come to the conclusion it's partly a matter of pressure - and outside air temp? Last time, the tanks did *not* develop frost. And last time I was able to turn the pressure from 5 to a max of 5.75 when the temp reached 1970. This got me to Cone 6. However, this time the gauge is maxed out at 5 - there is no option to go .75 higher.

 

Looking forward to firing it again with someone by my side who actually knows what they're doing.

[Kristin_Gail]

According to my ten-pages-per-firing-nutso-notes, it was 36 degrees outside when I began both Firing #1 and #2, and both times the pressure was maxed at just over 5. Stuck at 1972F both times. Both times finished with wood.

For Firing #3 it was 55 degrees outside when I began, and I could get the pressure to 5.75. Which was just barely enough to get to Cone 6.

It's about 40 outside now (Firing #4), and 5 was the max on the gauge, 1976 max temp.

 

Is there a way to add the B2 to the mix? Use all three of them at the end?

[neilestrick]

So, then what happened?

[Mark C.]

Its like  the end of the novel is torn off -who knows how it ends??

Got up to temp?

kiln stalled?

Ran out of gas?

Fell asleep?

gave up on ceramics as its to easy?

Mark

[neilestrick]

Zombie apocalypse?

[Kristin_Gail]

Ha!  I was so cold when I was typing, I must not have made sense.  I turned everything off after watching it be terminally stuck at 1976 for an hour or so.  I didn't know of any other options to heat it to Cone 6 besides adding wood, and I didn't want to go that route.  So I guess, in the end, I just did a bisque.  Possibly with part of the kiln in reduction for part of the firing.

 

My last post above was my post-firing evaluation:  I'm convinced that, if it had been twenty degrees warmer outside, I would have been able to turn up the burners just a smidgen and would have made it there - but slowly.

 

Marc has told me before that I won't be able to use the kiln in the winter.  I told him I wouldn't want to be out there if it was below freezing, anyhow.  I didn't realize it had to be above 50F.

 

My synopsis to a friend today was that the inability to reach temperature is a function of the kiln/chimney/burners/atmospheric conditions (one or all, would love to know).  But the quality of the firing - the atmosphere within the kiln, etc. - that's all my fault, a result of inexperience.  

 

I really don't know what I could have done to make it get any hotter.  Although I am, obviously, open to suggestions.

 

Husband wants to fire it up again once it gets warmer.  I don't want to do so unless I have someone experienced with me.  Will be working this week on sweet-talking the instructor from the craft college - although he lives more than two hours away, so I think I'll be into it for more than a batch of cookies.

[Mark C.]

Marc has told me before that I won't be able to use the kiln in the winter

 

Refresh my memory on which part of the artic you live in??

Its almost JUNE and winter is stlll around?

Wait I get it you are in the southern half of the globe-near patagonia?

 

On a more real note that little kiln should fire right up to cone 6 its just a burner/propane isssue.

I do not think adding wood is your only way to get hotter-maybe a better burner setup .

 

On my salt kiln I use 4 of those MR 100s and its larger than your setup stacking area wise. I choose those burners as salt is eating them up big time and they are cheap and I do not care when they go as I spray salt right next to them.

I use low pressure natural gas-a very different fuel than propane-actually less BTUs.

Mark

[Stephen]

What about John's experiment with the one burner high pressure system from your old kiln? 

[Kristin_Gail]

Honestly, it's crazy.  The feels-like temperature was 36F yesterday.  May 27.  

 

If I reach a certain temp with the B2, then switch to the MR100s, I would still be using the MR100s when I reached this magic 1970 number.  So I don't understand how it will help - unless the MR100s will not backburn when started at such a later point in the firing, and therefore burn better.

[bciskepottery]

So, is it time for an informal "fund-raiser" among students participating (actively/lurkingly) to this thread to send one of our esteemed kiln firers (hey, John B.) on a road trip to Canada for an endless winter experience in helping fire/troubleshoot the kiln? Or, do we wait for Season 2 of Real Time Kiln Advice to hit netflex so we can binge?

[Kristin_Gail]

Yes, now that would be entertaining.  Spend a couple thousand bucks to get someone up here (John's the closest!) so they can take one look at it, shake their head, and say, "Ohmygawd I cannot believe I just drove all this way.  Take the damn cover off the chimney!" or someone equally as ridiculous.

 

Husband wants to drill a third hole in between the burner ports, plug it up through 1970, then open it and add the B2, on a 20-lb tank. 

 

Or I can do John's experiment.

 

Or I can build a power burner.

 

Or I can re-build the chimney, narrower (okay, this one has never been suggested, but you never know).

 

Or ... Can I somehow make the MR100s run on a high-pressure system?

 

Or ... I think the possibilities are endless, eh?

[Guest JBaymore]

Sorry... we had matsuzaki Ken-san doing a workshop today at the college.  Been gone all day til now.

 

What size propane tanks do you have on that kiln again? 

 

best,

 

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

 

PS:  Ther are lots of options... don't give up . ..... but don't rush either.

[bciskepottery]

Sorry... we had matsuzaki Ken-san doing a workshop today at the college.  Been gone all day til now.

Serious case of workshop envy starting in 5, 4, 3, 2, 1 . . .

[Kristin_Gail]

Nope.  No rushing, no giving up.  I'm in for the long haul on this one!  It's fun.

 

I have two 100-lb tanks.

 

And now I'm off to watch Ken Matsuzaki videos.

[Mark C.]

Did you ever decide that your regulator was high volume and adjustable?

Mark

[Kristin_Gail]

The regulator, we decided, was some basic one used on RVs?  I'll go back and find the link.  It is slightly adjustable - I opened it up and dialed it down as far as it could go.  I believe Marc said it went from 10-12?  

 

Here's the regulator:  http://www.jmesales.com/product/gas-flo-low-pressure-two-stage-lp-gas-regulators,11045,7914.htm

 

And here's the page where we went 'round about on the regulator issue:  http://community.ceramicartsdaily.org/topic/5746-troubleshooting-this-converted-kiln-o-mine-taller-chimney/page-2

[Mark C.]

I'm not sure about round and round-this is from that old thread-

John said

 

(I'm thinking that unless you want to change out the orifices, that you should look more at a low pressure (11" Water Column) HIGH VOLUME regulator.  Regulators have two ratings...... delivery pressure and total gas volume that they can pass in a unit of time (minute / hour).  The issue here is likely volume... not pressure (see my comments above).

So I'm also  thinking that a new regulatior is something you can try-and its cheap.

They have a threaded knob on top to adjust the flow and it a high volume deal-low pressure.

I'd order one up and see what that does-since you are off the beaten track you need to mix it up-we all know what you have is not working

No need to do the same again-I suggested another ransome burner but 1st and for far less $ a regulator may help and if you later get another burner you still need a high volume regulator.

Mark

[Kristin_Gail]

I just re-read the regulator section of that thread, and it sure seems as though it was a consensus to change to that specific regulator. But why didn't I? If I remember correctly, I thought someone said it wasn't the right one, as it says right on it "high pressure." But now I can't find this comment, so I was obviously confused. Also, in the middle of the discussion, I called Marc and he said just to turn up the regulator I already had.

 

Here's the suggested regulator: http://www.amazon.com/Bayou-Classic-5HPR-40-Adjustable-Regulator/dp/B0033JF0GE

 

I'm certainly more than happy to give this a go.

[TJR]

O.K. I am not getting the reference to Canada. Are you IN Canada?

Weather today is 28 degrees Celsius.82.4 F.

We don't fire propane in the winter as the tanks freeze up. But it's not winter all the time.

Lets have some more pics of your kiln.

I still say crank those primaries down to one quarter inch.

You do not have to build your chimney narrower. That is what the damper is for.

As John stated, make one change at a time.

TJR.

[Kristin_Gail]

Yessir, I'm in New Brunswick.  It will be warmer today - 72!  Balmy.  It's generally winter here from mid-October through mid-May.  Spring for a few months, autumn for a weekend or two.  Never summer.  (In comparison to my previous life as a Midwestern American and Ontario-dweller.)

 

Really, more photos of this thing?  I can do that.  I tried to take a video of the entire system, from tank to chimney top, but am having memory issues on the iPad.

 

Chimney rebuild reference was meant to be a far-reaching idea of the list of possibilities - just kidding, really.  Although I'm pretty much open to anything.

 

But yes, one change at a time.  

 

Curtis might just have a regulator for me, you never know.