Venting a kiln yourself

[neilestrick]

7 minutes ago, nafeeza said:

I used the preprogrammed schedule for cone 5 on medium. 

Try it on slow, or do a custom program like a mentioned before, with 100F/hr for the last 400 degrees.

[Bill Kielb]

2 hours ago, neilestrick said:

Try it on slow, or do a custom program like a mentioned before, with 100F/hr for the last 400 degrees.

Not sure, it’s a 2100 watt 1/2 cu ft test kiln.  Ought to heat like a rocket ship, no?

[neilestrick]

4 hours ago, nafeeza said:

I used the preprogrammed schedule for cone 5 on medium. 

Scratch my last advice. Do full speed for the last 300 degrees. I just remembered that's what I had to do on that other kiln.

[neilestrick]

2 hours ago, Bill Kielb said:

Not sure, it’s a 2100 watt 1/2 cu ft test kiln.  Ought to heat like a rocket ship, no?

Not necessarily. I had a near identical Paragon test kiln in the shop recently that was essentially brand new. It gave a FTH code on every firing setting, including custom programs. I put in a new controller (Sentry Xpress 3 button), new relay, new elements, new thermocouple and wire, etc. Everything! Nothing helped. What I figured out was that the controller wouldn't adapt to the needs of the firing. Unless it was programmed to go full power, it would continue to cycle the relay every few seconds even though it needed to stay on full power towards the end of the firing. With the relay cycling, even doing it quickly, the elements wouldn't put out enough heat to get the job done. The solution was to do a custom program with the final 300 degrees set at full power. That kiln is only rated to cone 8, so it doesn't have a lot of power to start with.

[Bill Kielb]

1 minute ago, neilestrick said:

Not necessarily. I had a near identical Paragon test kiln in the shop recently that was essentially brand new. It gave a FTH code on every firing setting, including custom programs. I put in a new controller (Sentry Xpress 3 button), new relay, new elements, new thermocouple and wire, etc. Everything! Nothing helped. What I figured out was that the controller wouldn't adapt to the needs of the firing. Unless it was programmed to go full power, it would continue to cycle the relay every few seconds even though it needed to stay on full power towards the end of the firing. With the relay cycling, even doing it quickly, the elements wouldn't put out enough heat to get the job done. The solution was to do a custom program with the final 300 degrees set at full power. That kiln is only rated to cone 8, so it doesn't have a lot of power to start with.

Hmm, interesting. Too bad they didn’t let you at the relay cycle timing. Might help, but it appears she can’t go 27 degrees an hour from the FTL error so something is decreasing the available power.

[neilestrick]

@nafeeza I also strongly recommend doing a controlled cooling if you want the firing to mimic that of a larger kiln. Add in a cooling cycle of 175F/hr from peak temp down to 1500F and the results will be pretty similar to what you'd get from a larger kiln.

[neilestrick]

Just now, Bill Kielb said:

Hmm, interesting. Too bad they didn’t let you at the relay cycle timing. Might help, but it appears she can’t go 27 degrees an hour from the FTL error so something is decreasing the available power.

The relay cycling is preventing the elements from reaching max output. They're just not on long enough at a time.

[nafeeza]

2 hours ago, neilestrick said:

Not necessarily. I had a near identical Paragon test kiln in the shop recently that was essentially brand new. It gave a FTH code on every firing setting, including custom programs. I put in a new controller (Sentry Xpress 3 button), new relay, new elements, new thermocouple and wire, etc. Everything! Nothing helped. What I figured out was that the controller wouldn't adapt to the needs of the firing. Unless it was programmed to go full power, it would continue to cycle the relay every few seconds even though it needed to stay on full power towards the end of the firing. With the relay cycling, even doing it quickly, the elements wouldn't put out enough heat to get the job done. The solution was to do a custom program with the final 300 degrees set at full power. That kiln is only rated to cone 8, so it doesn't have a lot of power to start with.

This might be a dumb question, but how would I set the kiln to full power? 

[Bill Kielb]

7 hours ago, nafeeza said:

This might be a dumb question, but how would I set the kiln to full power? 

Not sure actually, I think his experience or workaround was to set a last 300  degree segment at 999 degrees per hour or max rate (full power). I think I got that right!  To me, if this actually works it is a workaround for a misbehaving controller. it’s more likely you are under powered for some reason. Whether that be relay or element or bad connection to one of the elements. Most kilns we see with this very spec will go 570 degrees per hour with a standard relay interval time of 14 seconds  so I am not sure why yours is different.

Worth a try though and would be interesting as test kilns like yours (1/2 cu ft) with a little over two thousand watts of power usually are more than adequately powered.

Finally you will need to guess where cone six bends. The simple answer to this is in the Orton chart. To get your cone to bend at a specific temperature is mostly dependent on the speed your kiln will go in the last 250-300 degrees of your firing. Orton knows this and provides three columns. If you can go about 108 degrees per hour in this last segment then the cone will bend at or near the temperature in that column. If your kiln goes slower during this period then cone six (or 5)  will be achieved at a lower temperature, closer to the first Orton column but as you might guess take a longer amount of time. That’s what is meant by heatwork, time + temperature.

The last 250-300 degrees of the firing is where most of the heatwork is done on your glazes, clay and of course cones (which are made of glaze). Like cooking a pizza, 5 hours at 180 degrees begets an awful pizza. But 15 minutes at 425 gets a nicely cooked one.

Since he ran into this condition in the past, it’s worth a try for sure.  Definitely not a dumb question!

[neilestrick]

12 hours ago, nafeeza said:

This might be a dumb question, but how would I set the kiln to full power? 

You'll have to do a custom program. It's worth trying a regular firing on slow to see if that works, but if not do a custom program. Step one could be 250/hr to 1800. Step 2 should be full/9999 to your peak temp. Step 3 should be 175/hr to 1500. The manual will tell you how to do a custom program.

@Bill Kielb The controllers I had were cycling much faster than 14 seconds, more like 5 seconds. And I don't think they were misbehaving, as I had two different controllers do it and they were purchased more than a year apart. I think it's just how they are.

 

Sentry Xpress 4.0 Manual.pdf

[Bill Kielb]

3 hours ago, neilestrick said:

You'll have to do a custom program. It's worth trying a regular firing on slow to see if that works, but if not do a custom program. Step one could be 250/hr to 1800. Step 2 should be full/9999 to your peak temp. Step 3 should be 175/hr to 1500. The manual will tell you how to do a custom program.

@Bill Kielb The controllers I had were cycling much faster than 14 seconds, more like 5 seconds. And I don't think they were misbehaving, as I had two different controllers do it and they were purchased more than a year apart. I think it's just how they are.

 

Sentry Xpress 4.0 Manual.pdf 2.03 MB · 1 download

Interesting. Well you had it, so definitely something she should try. The cycle time is really more like the time it takes two outputs coming on two successive times. Just a mechanical relay limitation parameter. When you move to SSR’s it changes to a much lower minimum.
 

Comparatively this is the same size and same power as most other test kilns so I am at a loss why it just can’t go really fast. It will be interesting if that solves her troubles which would really point to the controller mismatching the thermodynamics or heating of the kiln so badly that it just doesn’t really work.  Good workaround though if it works.  Probably not something  that took a bit of testing. 
Not sure what to pick as a peek temp but that can always  be approximated. It would be fun to know what these kilns are capable in speed at the top end.

[nafeeza]

@Bill Kielb I should’ve also mentioned that this is a discontinued kiln that’s probably why I got it at a bargain price lol others probably noticed it wasn’t up to par.

 

as of right now, I have my kiln going on a schedule that includes a segment on full speed and another with a cool down. So I will keep you guys updated on how it comes out!

[Bill Kielb]

1 hour ago, nafeeza said:

@Bill Kielb I should’ve also mentioned that this is a discontinued kiln that’s probably why I got it at a bargain price lol others probably noticed it wasn’t up to par.

 

as of right now, I have my kiln going on a schedule that includes a segment on full speed and another with a cool down. So I will keep you guys updated on how it comes out!

Hopefully this works. Since this is a used kiln it may have had firings on it. If you have success, then great it is solved. If not, I have have read most of this kilns tech manual (which actually is an Orton control) and have saved your wiring diagram and some other pertinent info that likely would allow this to be solved. Discontinued or not, it has  enough energy to fire so there are some simple checks that can be done.

Hopefully it works for you, if not we likely can get it to so no worries.

[nafeeza]

@Bill Kielb @neilestrick 

hey guys! So I woke up early this morning excited to check the kiln only to see it’s still getting the ftl message  

[Bill Kielb]

2 hours ago, nafeeza said:

@Bill Kielb @neilestrick 

hey guys! So I woke up early this morning excited to check the kiln only to see it’s still getting the ftl message  

Can you take a few pictures and and are you able to measure the resistance of your elements?

[neilestrick]

3 hours ago, nafeeza said:

@Bill Kielb @neilestrick 

hey guys! So I woke up early this morning excited to check the kiln only to see it’s still getting the ftl message  

Any idea how hot it got? Odd that it made it to cone 5ish on medium speed but not on full speed. Could be elements, could be a sticky relay or bad thermocouple. Can you post some pics of the elements and thermocouple?

[nafeeza]

I don’t know if I’m supposed to pull the elements out to see it because I can’t really see them from inside the kiln. 

I think it got close to cone 5 on full mode because my glazes still came out good again. 

@neilestrick @Bill Kielb

[Bill Kielb]

1 hour ago, nafeeza said:

I don’t know if I’m supposed to pull the elements out to see it because I can’t really see them from inside the kiln. 

I think it got close to cone 5 on full mode because my glazes still came out good again. 

@neilestrick @Bill Kielb

 

 

I believe it’s likely your elements and or could be made worse by a marginal connection and relay. If you have someone that can measure them, they need to be 13.1 ohms. If they are in the 14-15 ohm range they are worn and need to be replaced. If any connection  to the elements and relay are worn due to heat it will also take away precious power from you firing.

To squeeze a few more firings out of these That are worn we typically slow down the top segment of the firing as the criteria is if the kiln has not increased by 27 degrees in an hour and the segment has run for at least four hours.  So you might get a couple firings with a 60 degree per hour top segment setting. 

At this point you have little power to spare so checking the elements is the thing to do for sure. We still don’t know if they all glow actually so I would encourage that first. Program a single segment firing to 500 degrees at 999 speed and see if top and bottom glow. If you are comfortable with removing power and opening up the control box to provide pictures of the relay connections and element connections we could easily see if they are burnt and worn.

I should mention if they are measured as is without removing any wires they should measure about 6.55 ohms because they are parallel connected. If they measure connected this way 7-8 ohms they need to be replaced. Just to add if you measure them with all wires connected and it measure 13 ohms or more, one of them is bad.

[nafeeza]

@Bill Kielb I just turn my kiln on to 500 and nothing is actually glowing 

 

when I first got this kiln I got a number from the paragon website for a kiln specialist. I originally contacted him about venting the kiln because I always thought that was the problem. I’ll try contacting him again about the worn elements. Not even sure if anyone will come out during this pandemic but maybe once this is all over. 

[neilestrick]

26 minutes ago, nafeeza said:

@Bill Kielb I just turn my kiln on to 500 and nothing is actually glowing 

 

when I first got this kiln I got a number from the paragon website for a kiln specialist. I originally contacted him about venting the kiln because I always thought that was the problem. I’ll try contacting him again about the worn elements. Not even sure if anyone will come out during this pandemic but maybe once this is all over. 

You may need to go hotter than 500. Set it at 1000F.

[Bill Kielb]

35 minutes ago, nafeeza said:

@Bill Kielb I just turn my kiln on to 500 and nothing is actually glowing 

 

when I first got this kiln I got a number from the paragon website for a kiln specialist. I originally contacted him about venting the kiln because I always thought that was the problem. I’ll try contacting him again about the worn elements. Not even sure if anyone will come out during this pandemic but maybe once this is all over. 

You have to look at it as it’s getting to 500, if it reaches that temperature it will shut off. Maybe to be sure, set it like Neil says to 1000 and look at it between 500 - 700 degrees. Both elements should be glowing red (Top and Bottom) if not, the one that doesn’t glow is definitely bad.

[nafeeza]

Hey again!

 

at around 700 degrees things started to glow. And it looks like the top and bottom elements are glowing 

 

I’m also going to order an ohm meter so I could check that. 
 

 

would it be a bad idea to keep using the kiln on full power during the last segment even tho it’s not reaching the correct temperature? Because my glazes seem to be coming out beautiful on that cycle. 
 

the bottom looks a bright red and I never got that before! The colors aren’t dull like they usually are. 
 

if It wouldn’t be a good idea to use it on cone 5 or 6, can I do low fires? Because I have a bunch of low fire glazes that I’d love to try! 

[neilestrick]

52 minutes ago, nafeeza said:

Hey again!

 

at around 700 degrees things started to glow. And it looks like the top and bottom elements are glowing 

 

I’m also going to order an ohm meter so I could check that. 
 

 

would it be a bad idea to keep using the kiln on full power during the last segment even tho it’s not reaching the correct temperature? Because my glazes seem to be coming out beautiful on that cycle. 
 

the bottom looks a bright red and I never got that before! The colors aren’t dull like they usually are. 
 

if It wouldn’t be a good idea to use it on cone 5 or 6, can I do low fires? Because I have a bunch of low fire glazes that I’d love to try! 

No danger doing that. But try doing full speed at the end to 2090F (cone 4), then add a 20 minute hold, which should get you to cone 5. Also do the 175F/hr to 1500 cool down. That way the kiln doesn't have to get as hot, and may prevent the error code.

[Bill Kielb]

13 hours ago, nafeeza said:

Hey again!

 

at around 700 degrees things started to glow. And it looks like the top and bottom elements are glowing 

 

I’m also going to order an ohm meter so I could check that. 
 

 

would it be a bad idea to keep using the kiln on full power during the last segment even tho it’s not reaching the correct temperature? Because my glazes seem to be coming out beautiful on that cycle. 
 

the bottom looks a bright red and I never got that before! The colors aren’t dull like they usually are. 
 

if It wouldn’t be a good idea to use it on cone 5 or 6, can I do low fires? Because I have a bunch of low fire glazes that I’d love to try! 

It is a bit concerning that these don’t glow sooner. This kiln needs its own dedicated circuit and all the connections, cord, plug, relay connections, element connections need to be well made. My suggestion is someone who is skilled should check all of these  as soon as practical. I would hate not to err on the side of safety and this has symptoms of voltage drop somewhere along the way between panel and elements. Better to be safe about it IMO.

After all we just saw a recent post for similar under power turn out to be a burning connector end. 

 

[neilestrick]

11 hours ago, Bill Kielb said:

It is a bit concerning that these don’t glow sooner. This kiln needs its own dedicated circuit and all the connections, cord, plug, relay connections, element connections need to be well made. My suggestion is someone who is skilled should check all of these  as soon as practical. I would hate not to err on the side of safety and this has symptoms of voltage drop somewhere along the way between panel and elements. Better to be safe about it IMO.

After all we just saw a recent post for similar under power turn out to be a burning connector end. 

 

I work on a lot of kilns that don't glow before 500F, especially on 120V kilns. I always set the program to 800F to give them time. Even at 600 F sometimes all you can see is a faint glow at the corners where the elements bunch up.

That said, @nafeeza  it's definitely worth checking all the connections in the control box. Also check to see if the power cord is getting hot during the firing. Take a look at the power cord and make sure it's a 20amp cord. The plug should have one prong turned 90 degrees to the other. I've run into a number of small 120 volt kilns where the owner changed out the cord so they could use it on their regular 15 amp household circuit. If the previous owner did that to your kiln, the cord could be overheating and causing a power drop.