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Programming Bartlett V6-Cf To Reduce Pinholes

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I thought I would start a new subject line rather than continuing to hijack the other one. I am trying to learn how to do some basic fine tuning of my glaze firing. I am going to start by trying to correct a pinhole issue I am having with one of my more popular glazes. I think the problem is that the temperature is dropping too quickly once reached and "freezing" the glaze before it has time to smooth out and heal over. I have a Bartlett V6-CF controller on my Olympic Kiln and I glaze fire to cone 6.

 

With help from people over on the other subject of firing schedules (thank you!) I read through the Bartlett manual again. I read it when I first got it but didn't understand most of what I was reading so bad me for not reading it again. It seemed easiest to simply cut and paste the info from the Bartlett Manual so I don't get it wrong.

This is their firing schedule for cone 6:

post-22921-0-14497100-1463520185_thumb.jpeg

 

Then I found this towards the back of the manual concerning a pre programmed vary fire program called User 6.

post-22921-0-74220400-1463520259_thumb.jpeg

 

They have something called a 16-S (16 segment program) under the menu section on the controller.

 

I played around with the controller and was able to turn on this special, 16-S, user 6 cool down program. I do have a question concerning their Important Notes section. I am using the preprogrammed slow glaze cone fire program and the preprogrammed user 6 slow cool program. I don't see anywhere to do the segment adjustment they are saying to do. What am I not getting?

post-22921-0-54005200-1463521572_thumb.jpeg

 

Once I get the programming figured out my firing schedule should look like this if I am understanding it correctly:

Slow Glaze

Cone 6, 2232F

150 degrees per hour to 250 degrees

400 degrees per hour to 1982 degrees

120 degrees per hour to 2232 degrees

Add on the Vary-fire User 6 Program (user 6 cone 6 cool down)

Temperature starts at 2232 degrees F then cools at its natural rate to 1900 degrees F

Then cools at 150 degrees F until it reaches 1500 degrees F at which point it then cools at its natural rate the rest of the way down to kiln opening temperature.

 

Am I getting this right? Will adding this onto my slow glaze schedule help reduce pinholes?

 

T

post-22921-0-14497100-1463520185_thumb.jpeg

post-22921-0-74220400-1463520259_thumb.jpeg

post-22921-0-54005200-1463521572_thumb.jpeg

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If you are using the pre-programmed slow glaze followed by the pre-programmed User 6 cool down, then it should work as you describe. The Important Note identifies an idiosyncrasy of all the self-programmed User x profiles in the Vary-Fire section. The first segment of any user program must be for an increase in temperature from wherever it happens to be when that profile starts. You cannot have a target temperature that is lower than the current actual temperature in the first segment. You can ramp down in segments 2 and later, but not in segment 1. If the target temp in ramp 1 is lower than current actual, the controller will just skip it. Soooo... in the pre-programmed User 6, segment 1 is programmed to have a target temperature of exactly where it is for the pre-programmed cone fire schedule just ending. The segment 1 command is go to 2232 as fast as possible (ramp rate 9999) and then immediately (no hold) go to segment 2. It's already there or maybe a bit above. That means segment 1 will effectively be skipped, and it will then follow segment 2 to cool as fast as it can (ramp rate 9999 again) to 1900, no hold, and then ease into segment 3 for the long slow drift down to 1500.

 

The meaning of the important note applies to a customized User 6 cool down that you might want to create to replace the factory pre-programmed User 6. Let's say you want to go from a standard cone fire to ^6 (2232) and then do some different magic with a slow ramp down to 2000, a quick ramp down to 1900, a slow ramp to 1700 with a hold, and end with a medium fast ramp down to 1500.  (I just made that up for discussion purposes, don't ask me what different magic it might do, I dunno).  That would appear to be 4 segments. However, because the S-16 click-over from cone mode to ramp mode will always ignore segment 1, you would have to program this special magic as 5 total segments, just put bogus enter enter enter into segment 1, and then program your new magic as segments 2 through 5.

 

As for solving the pinholing, this slow cool might or might not do anything. This special cooling ramp contains an immediate natural cool to 1900, with the slow cooling for microcrystalline development in the glaze occurring after that. In the previous discussion, the pinholes are resolved either by a hold at maximum temperature or a slower than usual ramp up into maximum temperature so that the pinholes have time to heal over while the glaze is still fully molten.

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Your testing this in your test kiln right? If so you need to also need to add some type of controlled cool on the way down so that you can also add that controlled cool to your bigger kiln so the results will be the same.

 

Something like 300F/hour will suffice. So I would try downramping from 2232 by 100F an hour and then hold for 15-30 minutes at 2132, then do 300F/hour until 1500F. Something like that. You might be over cone 6 with this schedule because of all the extra heatwork, so add cones in the firing to see what you get. Might need to adjust the downramp to 200F from 2232F. So you go down from top temp over a half hour instead of a full hour.

 

Edit: I would probably start with a downramp of 200F from 2232F then hold for 15 minutes at 2132F. I think if you slow cool by 100 thats an entire hour between cone 5 and 6 your definitely going to be at cone 7 probably. So that is a bad schedule. 

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When using the user 6 program as part of the 16 segment option with a Cone Fire going up, segment 1 of user 6 is not used. It does not matter what you put in for segment 1. The controller will skip it and go directly to segment 2. But if you're combining User 5 going up and User 6 for a 16-S, then segment 1 of user 6 must be an up ramp or it will be skipped.

 

Yes, I use Slow Glaze to cone 6, then add on user 6 with a rate of 175/hr to 1500F. I prefer this because my glazes get to spend a little more time and the high end, and it gives me equal results from all of my kilns. If you crash cool to 1900F, that segment of the cooling could be radically different between large and small kilns, which can give different results. Plus the crash cooling will do nothing to help the pinholing. You need more flow to fix the pinholes, which means more time at the high ned.

 

Put up a picture of the pinholes. Is it a commercial glaze or one you mixed?

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I thought I would start a new subject line rather than continuing to hijack the other one. I am trying to learn how to do some basic fine tuning of my glaze firing. I am going to start by trying to correct a pinhole issue I am having with one of my more popular glazes. I think the problem is that the temperature is dropping too quickly once reached and "freezing" the glaze before it has time to smooth out and heal over. I have a Bartlett V6-CF controller on my Olympic Kiln and I glaze fire to cone 6.

 

With help from people over on the other subject of firing schedules (thank you!) I read through the Bartlett manual again. I read it when I first got it but didn't understand most of what I was reading so bad me for not reading it again. It seemed easiest to simply cut and paste the info from the Bartlett Manual so I don't get it wrong.

This is their firing schedule for cone 6:

attachicon.gifimage.jpeg

 

Then I found this towards the back of the manual concerning a pre programmed vary fire program called User 6.

attachicon.gifimage.jpeg

 

They have something called a 16-S (16 segment program) under the menu section on the controller.

 

I played around with the controller and was able to turn on this special, 16-S, user 6 cool down program. I do have a question concerning their Important Notes section. I am using the preprogrammed slow glaze cone fire program and the preprogrammed user 6 slow cool program. I don't see anywhere to do the segment adjustment they are saying to do. What am I not getting?

attachicon.gifimage.jpeg

 

Once I get the programming figured out my firing schedule should look like this if I am understanding it correctly:

Slow Glaze

Cone 6, 2232F

150 degrees per hour to 250 degrees

400 degrees per hour to 1982 degrees

120 degrees per hour to 2232 degrees

Add on the Vary-fire User 6 Program (user 6 cone 6 cool down)

Temperature starts at 2232 degrees F then cools at its natural rate to 1900 degrees F

Then cools at 150 degrees F until it reaches 1500 degrees F at which point it then cools at its natural rate the rest of the way down to kiln opening temperature.

 

Am I getting this right? Will adding this onto my slow glaze schedule help reduce pinholes?

 

T

I think you could help the pin holing problem by changing your last ramp to cone 6. Instead of 120 F ramp   go to 80 F ramp than go to cone table and hit cone 6.  The controller will then calculate the temperature required to go at a 80 deg F ramp to cone 6.  You may also find that with this slower ramp you don't need the cool down.

The final temperature will now be around 2218 F instead of 2232 F.  You can verify this after the firing by hitting the review button.  If you review the program before firing it will say 80 F ramp cone 6

David

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It took me awhile to get back to this but after reading here and the manual some more I think I need to try programming my Bartlett V6-CF using the vary-fire program and the using cone fire option in the last segment. I am going to try to work on the pinholing issue first. I basically used the same schedule as the Slow Glaze Fire EXCEPT that I slowed it down to 80 degrees from the original 120 degrees for the final ramp up to cone 6 in segment 3. This number was mentioned previously, is this a good ramp rate per hour? Too slow too fast? Will doing this give the glaze time to flow and minimize pin holes?

 

I would greatly appreciate those of you that are familiar with this controller checking the schedule I have used to see if anything jumps out as bad.

 

Below is the info as it flashes back at me when I do the review program option after entering what I think are the correct criteria and setting the schedule to fire under USER 1.

 

USER 1

SEGS 3

RA 1 150

F 1 250

HLd 1 0.01

 

RA 2 400

F 2 1982

HLd 2. 0.01

 

RA 3 80

CONE 6

HLd 3 0.01

 

DELA 0.00

 

ALRM 9999

 

ERCD ON

 

FIRE 131

 

I am unsure on the HOLD (HLd) for each segment but the manual doesn't show as far as I can tell a hold on each segment under the slow glaze cone fire option, is this correct? Or do I need a hold for each segment? It required a number to be chosen under the Hold so I chose the smallest one of 0.01.

 

Also, I think by slowing it to 80 per hour (from 120 per hour) my length of firing will increase by 1 hour? Just wondering if that's how it will work.

 

Thanks a bunch everyone!

T

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I think you can push enter when setting hold and keep it at 0.00, no hold should be required. I guess one minute isn't an issue really but 0 should be ok.

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It took me awhile to get back to this but after reading here and the manual some more I think I need to try programming my Bartlett V6-CF using the vary-fire program and the using cone fire option in the last segment. I am going to try to work on the pinholing issue first. I basically used the same schedule as the Slow Glaze Fire EXCEPT that I slowed it down to 80 degrees from the original 120 degrees for the final ramp up to cone 6 in segment 3. This number was mentioned previously, is this a good ramp rate per hour? Too slow too fast? Will doing this give the glaze time to flow and minimize pin holes?

 

I would greatly appreciate those of you that are familiar with this controller checking the schedule I have used to see if anything jumps out as bad.

 

Below is the info as it flashes back at me when I do the review program option after entering what I think are the correct criteria and setting the schedule to fire under USER 1.

 

USER 1

SEGS 3

RA 1 150

F 1 250

HLd 1 0.01

 

RA 2 400

F 2 1982

HLd 2. 0.01

 

RA 3 80

CONE 6

HLd 3 0.01

 

DELA 0.00

 

ALRM 9999

 

ERCD ON

 

FIRE 131

 

I am unsure on the HOLD (HLd) for each segment but the manual doesn't show as far as I can tell a hold on each segment under the slow glaze cone fire option, is this correct? Or do I need a hold for each segment? It required a number to be chosen under the Hold so I chose the smallest one of 0.01.

 

Also, I think by slowing it to 80 per hour (from 120 per hour) my length of firing will increase by 1 hour? Just wondering if that's how it will work.

 

Thanks a bunch everyone!

T

You don't need a hold and can enter 0 instead.  I would enter a temperature for ramp 2 of 2018 and a hold of 0.05 minutes. You don't need ERCD on, if it is on and the elements are lagging behind temperature it can shut the kiln off.  Make sure you press review program and ramp 3 says 80 cone 6, before starting the kiln.  Also since this is your first time try to be around for ramp 3 , and make sure it is ramping up at 80 deg by pressing the  review seg button.  After the firing hit review and it will show the final temperature.  If the cones don't show quite enough heat work than you can play with a hold for ramp 3.  You should not need any more than a five minute hold.

David

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Thank you David. It's kind of scary to be doing this for the first time but need to learn it as I've relied on the preprogrammed slow glaze setting for too long. everyone here that programs their own schedules to get the exact result they want have inspired me to try as well.

 

A question why would you go to 2018 for ramp 2 instead of 1982? And adding the 5 minute hold here? Is there something that happens to the glaze at this temperature? Just curious and wanting to Learn!

 

Getting close! I think it's time to run a test load through and see what I get. I'm going to glaze up a bunch of stuff with the glaze I am having issues with and see if this schedule helps. If not at least I will have something to photograph to show what the issue looks like. So far I have been able to grind the little pimples and bumps down, reglaze and refire with good results. A few that failed in the refire I broke up.

 

T

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Thank you David. It's kind of scary to be doing this for the first time but need to learn it as I've relied on the preprogrammed slow glaze setting for too long. everyone here that programs their own schedules to get the exact result they want have inspired me to try as well.

 

A question why would you go to 2018 for ramp 2 instead of 1982? And adding the 5 minute hold here? Is there something that happens to the glaze at this temperature? Just curious and wanting to Learn!

 

Getting close! I think it's time to run a test load through and see what I get. I'm going to glaze up a bunch of stuff with the glaze I am having issues with and see if this schedule helps. If not at least I will have something to photograph to show what the issue looks like. So far I have been able to grind the little pimples and bumps down, reglaze and refire with good results. A few that failed in the refire I broke up.

 

T

The top temperature for a 60 ramp rate will now be around 2218 F minus 200 deg = 2018 F.  Orton cone tables are for the last 200 deg F of the firing.  The 5 minute hold is to give the kiln a chance to level out the temperature before starting the final ramp. You can stay with 1982 but all that does is make for a longer total firing firing.  You can play around with the hold if you want.  As for a hold at the end of the firing I usually start  with a 3 minute hold and add to it if necessary.  If you are refiring ware than you may want to go slower on the second ramp, especially if refirng plates, 350F  works for me.

David

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I am not an expert at glaze chemistry, but as it happens I have an Olympic kiln and am also dealing with a pinholing issue.  I did a ton of reading on it, and learned a few things.  So here goes:  Boron glazes blister when overfired, so Digitalfire.com says you should trying firing slowly in the last 200 degrees before reaching maximum temp.  You can then reduce the soak because you will build up heat work.  Tony Hanson's article on boron helped a lot.  Does your glaze have a high amount of boron?  If so, try reducing the boron. My faulty glaze is high in boron, so I'm mixing about 5 100gram batches and reducing the boron by 2% in each one.  Also, is the glaze high calcium or talc?  These ingredients have high surface tension, which can cause pinholing.  I believe a slow cooling helps with this. Below is the ramp I'm working with to try to reduce pinholes.   I'm not going to cone 6 but may go back to a higher temp; I just replaced a new thermocouple that was only a month old.  It went haywire.

Good luck.  Glaze faults are really frustrating.

Janice in Warner Robins, GA 

P.S.  Call Olympic about how to program the V6CF.  Their support people are very good.

 

#/ Ramp per hour/To Temp /Hold (optional)  

1 100 200        

2 150 500      

3 400 2124        

4 100 2160      

5 100 2124 15      

6 999 1800            

7 50 1400                                   

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I am not an expert at glaze chemistry, but as it happens I have an Olympic kiln and am also dealing with a pinholing issue.  I did a ton of reading on it, and learned a few things.  So here goes:  Boron glazes blister when overfired, so Digitalfire.com says you should trying firing slowly in the last 200 degrees before reaching maximum temp.  You can then reduce the soak because you will build up heat work.  Tony Hanson's article on boron helped a lot.  Does your glaze have a high amount of boron?  If so, try reducing the boron. My faulty glaze is high in boron, so I'm mixing about 5 100gram batches and reducing the boron by 2% in each one.  Also, is the glaze high calcium or talc?  These ingredients have high surface tension, which can cause pinholing.  I believe a slow cooling helps with this. Below is the ramp I'm working with to try to reduce pinholes.   I'm not going to cone 6 but may go back to a higher temp; I just replaced a new thermocouple that was only a month old.  It went haywire.

Good luck.  Glaze faults are really frustrating.

Janice in Warner Robins, GA 

P.S.  Call Olympic about how to program the V6CF.  Their support people are very good.

 

#/ Ramp per hour/To Temp /Hold (optional)  

1 100 200        

2 150 500      

3 400 2124        

4 100 2160      

5 100 2124 15      

6 999 1800            

7 50 1400                                   

The last 200 deg of fireing is suppose to be at a specific rate, in your case 100 deg ramp.  This then means, segment 3  top temp should be 1960 and then ramp at 100 deg to 2160 deg, probably no hold is needed. 100 deg ramp is still quite fast that is why. the previous post said 80 deg ramp.  As far as testing for boron you could make a 100 gram batch of glaze without the material that adds boron and then add 2% of that material back in and put it on a test tile, keep doing this at 2% amounts, putting each on a test tile until you are back to the original amount.

David

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