Hulk

Hi LilClayLady!

Is that kiln max temp rating cone 6?
Here's the documentation I found:
Item # B23HT-240 On Cress Mfg. Co.
If so, it might be more serviceable for low fire. Likely it will struggle to reach cone 5 once new elements have started to wear/degrade.
Likely it wouldn't take many firings to lower the actual max.
As for being worthwhile, the condition of the unit* and how it matches up with your expectations could matter more than its age.
*bricks, casing, wiring, stand, everything, including the control mechanism.
My kiln is over thirty years old, it's a cone 10 though, so suitable for cone 5/6 work. Its bricks and lid are going, so I'll likely upgrade when the elements wear out. It might take another fifty firings to wear'm out. The seller included a full set of posts, brand new shelves, boxes of cones, and some glaze materials - so far, it's been a fair deal.

My first question about such a phenomenon is whether the pot was washed before glazing.  Washing a piece with a damp sponge puts some moisture into the pot that allows for a smoother application of the glaze, often taking care of some pin hole bubbles that get in underneath the glaze rising to surface.  I always wash the pot with a damp sponge, or dip the pot in clean water before glazing.  How I determine which method to use depends on the number of pots I am glazing. The dip wash is fast, and works well if glazing a lot of pots as the first dipped ones will dry enough to glaze as evenly as a few fresh sponge washed pots.
 
best,
Pres 

Hi LilClayLady!

Is that kiln max temp rating cone 6?
Here's the documentation I found:
Item # B23HT-240 On Cress Mfg. Co.
If so, it might be more serviceable for low fire. Likely it will struggle to reach cone 5 once new elements have started to wear/degrade.
Likely it wouldn't take many firings to lower the actual max.
As for being worthwhile, the condition of the unit* and how it matches up with your expectations could matter more than its age.
*bricks, casing, wiring, stand, everything, including the control mechanism.
My kiln is over thirty years old, it's a cone 10 though, so suitable for cone 5/6 work. Its bricks and lid are going, so I'll likely upgrade when the elements wear out. It might take another fifty firings to wear'm out. The seller included a full set of posts, brand new shelves, boxes of cones, and some glaze materials - so far, it's been a fair deal.

Hi LilClayLady!

Is that kiln max temp rating cone 6?
Here's the documentation I found:
Item # B23HT-240 On Cress Mfg. Co.
If so, it might be more serviceable for low fire. Likely it will struggle to reach cone 5 once new elements have started to wear/degrade.
Likely it wouldn't take many firings to lower the actual max.
As for being worthwhile, the condition of the unit* and how it matches up with your expectations could matter more than its age.
*bricks, casing, wiring, stand, everything, including the control mechanism.
My kiln is over thirty years old, it's a cone 10 though, so suitable for cone 5/6 work. Its bricks and lid are going, so I'll likely upgrade when the elements wear out. It might take another fifty firings to wear'm out. The seller included a full set of posts, brand new shelves, boxes of cones, and some glaze materials - so far, it's been a fair deal.

They're quite heavy so they don't move around a lot. I put mine on the back seat of a convertible mini and drove about 300 miles from the borders of Scotland to the islands and it never moved. If it can take those roads, it can take anything

@Min, I googled custom large cookie cutters. . . . .one promising site is: https://www.cheapcookiecutters.com/collections/custom-cookie-cutters. You can check the same way, many sites showed up, it would mean checking reviews etc. Lots of times a lead in of best rated helps with searches for quality.
best,
Pres

Hi Gracie and welcome to the forum.
What I think is happening is your clay is porous to a degree that water is seeping through the clay through the crazed glaze (those fine cracked lines) and leaving soluble salts deposited in the craze lines on the surface of the pot. You could try thoroughly drying the vase out and adding a sealant to the inside of the vase. Another alternative would be to use a jam jar or some some thing to hold the water inside the vase and leave it as it is. Is this a pot you made or one that was bought or gifted to you?

I use local Anchorage clay, it’s considered a mediocre red earthenware here, no one really uses it. You’ve got to be discriminating when collecting to get the good plastic stuff and I add 1.5% veegum to help it play nice.
Interestingly, at 04 it’s a bright orange, porous, but strong earthenware..  at 03 it is darker, completely vitreous (<1% absorption), and really strong. Like, I drop it on the floor and it bounces kind of strong. At cone 3-1/2 it’s a bloating slumpy mess. 
This is as opposed to the clay I got from Sheep Mountain a couple hours away. Threw like a dream right out of the bucket. Firing was a different story. Went from earthenware to ceramic foam in one cone. And I mean foam, frothy bubbling foam. 
Love the Rabbit holes. 

Have logged many hours on a triple beam, but didn't own one when fitting the studio - inexpensive 2000g digital works fine for me, for glaze batches and up to 4.4 pound clay balls.
I've an analog multimeter; it shows variation better than a digi, and although there's an argument for accuracy, at the range I'm working in (cheap instrument and basic electrical stuff), it's more than fine and what I'm used to. I have my Dad's Simpson, but never use it.
We have digital bath scales, inexpensive and easy to read, just remember to calibrate Every Time it's moved, and replace batteries, hmm, that it's quiet puts it over a spring scale, just.
What we have that's still analog likely a shorter list!
Floor pump for bike tires, integrated analog pressure gauge. Repeatability is what matters, meh.
Car tire pressure gauges, all analog.
Everyday calipers, analog/vernier over cheap dial indicator types, whether mech or digi. I have a large vernier, very high quality, and a few small quality dial indicator types, also analog micrometer set. I don't mind vernier or mech dial indicators for thousandths o' inch, nor analog micrometers, having worked with all for hours countless.
Thermometers, all we have are liquid bulb and capillary type, excepting the cars' displays are numeric.
No doubt there's more, not remembering just now.
Digital doesn't always mean better, nor necessarily mean the sensing strategy is any different, more accurate, or better.
That said, some new stuff is cool.
Some old stuff is still cool too.

Have logged many hours on a triple beam, but didn't own one when fitting the studio - inexpensive 2000g digital works fine for me, for glaze batches and up to 4.4 pound clay balls.
I've an analog multimeter; it shows variation better than a digi, and although there's an argument for accuracy, at the range I'm working in (cheap instrument and basic electrical stuff), it's more than fine and what I'm used to. I have my Dad's Simpson, but never use it.
We have digital bath scales, inexpensive and easy to read, just remember to calibrate Every Time it's moved, and replace batteries, hmm, that it's quiet puts it over a spring scale, just.
What we have that's still analog likely a shorter list!
Floor pump for bike tires, integrated analog pressure gauge. Repeatability is what matters, meh.
Car tire pressure gauges, all analog.
Everyday calipers, analog/vernier over cheap dial indicator types, whether mech or digi. I have a large vernier, very high quality, and a few small quality dial indicator types, also analog micrometer set. I don't mind vernier or mech dial indicators for thousandths o' inch, nor analog micrometers, having worked with all for hours countless.
Thermometers, all we have are liquid bulb and capillary type, excepting the cars' displays are numeric.
No doubt there's more, not remembering just now.
Digital doesn't always mean better, nor necessarily mean the sensing strategy is any different, more accurate, or better.
That said, some new stuff is cool.
Some old stuff is still cool too.

Thank you for sharing Gep!
It's one thing to gain experience and knowledge through experience, another to systematically apply same and improve, and yet another to clearly, concisely and successfully communicate how you are doing it. Nice work!

Thank you for sharing Gep!
It's one thing to gain experience and knowledge through experience, another to systematically apply same and improve, and yet another to clearly, concisely and successfully communicate how you are doing it. Nice work!

Thank you for sharing Gep!
It's one thing to gain experience and knowledge through experience, another to systematically apply same and improve, and yet another to clearly, concisely and successfully communicate how you are doing it. Nice work!

@ATauer Some good info HERE.

The boards are* supplied by Minarik.
Registration is required to get the docs, here: minarikdrives.com
Mine exhibits same capacitor thing, however, within a few minutes, it's drained off.
My wheel has the pcmxp ("ssx") board; Skutt also uses the mm23001c board (as standard - it's perfectly suitable).
Minarik Drives
   XP Series
   User Manual
fifty page document has a chapter on calibration (trim pots); it's seven pages, however, several sections refer to other chapters for background info, etc. 
I bumped up the MAX SPEED and changed the IR COMP setting.

*or were; my Skutt will be coming up on five years old.
I haven't looked at their website, nor Minarik's, for several years.
...don't know why Skutt doesn't have the manual or at least some excerpts available. Oh well, their support is super, my bet is they would be helpful - I was able to find the doc myself - it was a Saturday, so.

The boards are* supplied by Minarik.
Registration is required to get the docs, here: minarikdrives.com
Mine exhibits same capacitor thing, however, within a few minutes, it's drained off.
My wheel has the pcmxp ("ssx") board; Skutt also uses the mm23001c board (as standard - it's perfectly suitable).
Minarik Drives
   XP Series
   User Manual
fifty page document has a chapter on calibration (trim pots); it's seven pages, however, several sections refer to other chapters for background info, etc. 
I bumped up the MAX SPEED and changed the IR COMP setting.

*or were; my Skutt will be coming up on five years old.
I haven't looked at their website, nor Minarik's, for several years.
...don't know why Skutt doesn't have the manual or at least some excerpts available. Oh well, their support is super, my bet is they would be helpful - I was able to find the doc myself - it was a Saturday, so.

The boards are* supplied by Minarik.
Registration is required to get the docs, here: minarikdrives.com
Mine exhibits same capacitor thing, however, within a few minutes, it's drained off.
My wheel has the pcmxp ("ssx") board; Skutt also uses the mm23001c board (as standard - it's perfectly suitable).
Minarik Drives
   XP Series
   User Manual
fifty page document has a chapter on calibration (trim pots); it's seven pages, however, several sections refer to other chapters for background info, etc. 
I bumped up the MAX SPEED and changed the IR COMP setting.

*or were; my Skutt will be coming up on five years old.
I haven't looked at their website, nor Minarik's, for several years.
...don't know why Skutt doesn't have the manual or at least some excerpts available. Oh well, their support is super, my bet is they would be helpful - I was able to find the doc myself - it was a Saturday, so.

Museum putty holds tighter; wax, also gel, are nice for clear/translucent objects, where putty would show more.
We found the putty well suited for the tall slender opaque vase, which has leverage. 

Hi, 
It is really really old. Could have contained 1 or two bronze bushings. Can't really tell. I think it may be too far gone to try to repair. Just getting the old bushing(s?) out would be a project. I don't have a metal lathe.


 

Well, I am officially a potter now, sort of. Still a long way to go but the foundation is there. We have a retail store that has done well and I finally left my corporate job to pursue pottery further (and our store). We have a shelf in the store to sell my wares and it does around 1k a month, I know it's not much but that is passive, it just sits there. looking forward to this next chapter in our lives!
My sponge holders have come a long way!

Another option, though hugely tedious, is to keep the mold moving, after you have filled it with slip. That way the bubbles are kept moving and can't settle in the plate wall.
You don't need to do it for the full 30 minute set period, but a few minutes, to move all the air bubbles, will usually suffice.  Filling the mold only half way, during this period, is the most effective. Once you've swirled the mold a few times then fill it to the top.
Years ago I delivered a few molds to a customer who used a "roto-caster" to cast large cement table bases. By keeping the mold in rotation they were able to cast large cement pieces with thin walls. I realized it might also work with casting slip and air bubbles. It does. 

Hi Bam,
Tony Hansen's digitalfire.com site has entries on each oxide, including colorants.
Ceramic Oxides (digitalfire.com) and an article on colorants Colorant (digitalfire.com)
I like Susan Petersen's book The Craft and Art of Clay, particularly the glaze section, which includes an entry on each important ingredient (including colorants) and clear discussion of unity.
I use cobalt carbonate, copper carbonate, rutile, tin oxide, chrome oxide, iron oxide, uhm, oh yeah, zircopax.

It's hard to tell from the pictures but if you look closely at the edge of the cracks is the glaze cut sharply across and not rounded into the cracks? Reason I ask is it looks like a cooling dunt to me. If the edges of the crack are sharp and not rounded over it means the crack happened while the kiln cooled, not on the heating up. Where in the kiln were the pots? top or bottom shelf pots worse? how fast did you cool the kiln? Is the outside of the pot glazed? Could you break one of those open and show the profile of the pot up close?
+1 for what Roberta said, gorgeous glaze!

@kristinanoel Your glaze is gorgeous!  Is it the same glaze you have been using?  And do you have the same glaze on the outside of the pot?  I ask this because of an experience I had last fall.  I put one glaze on the interior and a different one on the exterior.  A combo I had never used before and what happened looked just like your photo.  
Roberta

Thank you to both Pres and Marc! Your comments were very helpful, I should be fine since I won't be working with clay on the professional level.