a few more questions re Advancer shelves...

[Kakes]

Hello, I just spent a couple hours reading up on Advancer shelves including all the posts here that came up on the search. I still have a few questions I'm hoping some of you might be able to answer  before I bite the bullet and spend the $$$.

I fire large stoneware slabs (up to 20") flat on small stoneware rods (1/4" diameter) to prevent cracking. Warping doesn't matter so much. Will they do anything different on Advancer shelves? Could I stop using the rods?  Right now I have the regular solid cheap shelves - forgot what they're called. 

Also, I have a downdraft vent on my kiln (skutt). Is this ok with Advancers? 

Trying to decide whether to wash the shelves -- I only use stoneware, which seems like it's ok not to wash. Do the shelves need to be flipped? (I hate messing with kiln wash, especially the clean up of shelves.) 

And finally, do I need to wash the ends of my kiln posts? I've never done this before, but I thought I read that it's a good idea with the advancers.

Thank you!

[Dick White]

We have been using Advancers and the less expensive Bailey version in our gas kilns at the college for many years. They do not need to be coated with kiln wash as any glaze runs just pop off with a stiff putty knife or the flat side of a worn green grindstone. As they are not washed, there is no up or down side; they go into the kiln however they are picked up from the rack. Yes, the ends of the posts need a light coat of wash as they will slightly fuse to the shelf. They have remained perfectly flat all these years, unlike regular shelves. There will still be some need to ensure the flat slabs can expand and contract, as we have seen some porcelain plucking as with other types of shelf. We use a bit of alumina hydrate in the foot wax - the wax burns off but leaves the alumina to act as little ball bearings for the ware to roll on. We also use them in our front-loader electrics, but must be very careful to mount them where they are between elements. The main "hazard" with them is you must not let them get wet. The water will be absorbed and must dry out very slowly; if not, the shelf will be like a piece of wet greenware in a bisque firing. Except that the steam explosion will blow out the side of the kiln. I have never heard anybody regret buying them.

[liambesaw]

I think the other risks besides water are they need to cool really slow, and they also conduct electricty very well, so only use in a kiln where there's no risk of an element popping or slumping.

[Bill Kielb]

Just one thing to add to @Dick White as everything he mentioned we find absolutely true and easily resolved as he detailed. All silicon carbide based shelves conduct electricity so use in an electric kiln needs just a touch more care than standard shelves with respect to potential electric shock.
At a minimum, ensuring  they not touch the elements is a basic necessity when loading and firing.  But perhaps more important  an awareness that they could cause electric shock if the shelf was touching an element and the kiln was on and a person touched the shelf.

Careful use in your own kiln should likely be no issue with reasonable use. Using these in a studio kiln, we would probably install a lid switch so power was disconnected to the elements whenever the lid was opened just to be extra safe.

we have never regretted getting these for sure, even the knock off shelves which are not as straight and a touch thicker but much cheaper.

 

[Kakes]

2 hours ago, Dick White said:

We have been using Advancers and the less expensive Bailey version in our gas kilns at the college for many years. They do not need to be coated with kiln wash as any glaze runs just pop off with a stiff putty knife or the flat side of a worn green grindstone. As they are not washed, there is no up or down side; they go into the kiln however they are picked up from the rack. Yes, the ends of the posts need a light coat of wash as they will slightly fuse to the shelf. They have remained perfectly flat all these years, unlike regular shelves. There will still be some need to ensure the flat slabs can expand and contract, as we have seen some porcelain plucking as with other types of shelf. We use a bit of alumina hydrate in the foot wax - the wax burns off but leaves the alumina to act as little ball bearings for the ware to roll on. We also use them in our front-loader electrics, but must be very careful to mount them where they are between elements. The main "hazard" with them is you must not let them get wet. The water will be absorbed and must dry out very slowly; if not, the shelf will be like a piece of wet greenware in a bisque firing. Except that the steam explosion will blow out the side of the kiln. I have never heard anybody regret buying them.

Thank you for your answers, Dick White. When you say "be careful to mount them where they are between elements.", do you mean that they shouldn't line up with a row of elements? Is this generally true with kiln shelves? I thought I just had to be careful of the thermocouple. I'm using a top loading electric kiln. This is my first year and I'm learning by doing!

[Kakes]

2 hours ago, Bill Kielb said:

Just one thing to add to @Dick White as everything he mentioned we find absolutely true and easily resolved as he detailed. All silicon carbide based shelves conduct electricity so use in an electric kiln needs just a touch more care than standard shelves with respect to potential electric shock.
At a minimum, ensuring  they not touch the elements is a basic necessity when loading and firing.  But perhaps more important  an awareness that they could cause electric shock if the shelf was touching an element and the kiln was on and a person touched the shelf.

Careful use in your own kiln should likely be no issue with reasonable use. Using these in a studio kiln, we would probably install a lid switch so power was disconnected to the elements whenever the lid was opened just to be extra safe.

we have never regretted getting these for sure, even the knock off shelves which are not as straight and a touch thicker but much cheaper.

 

Thank you, Bill. Should I turn off the electricity to the kiln when loading or unloading with these shelves? I have a kill switch which I've always just left on. Is this a bad idea generally?

[Bill Kielb]

23 minutes ago, Kakes said:

Thank you, Bill. Should I turn off the electricity to the kiln when loading or unloading with these shelves? I have a kill switch which I've always just left on. Is this a bad idea generally?

Never a bad idea to shut off the kiln with your disconnect. Here in the states very few kilns come with lid safety switches yet many EU kilns require them. Most kilns use mechanical relays to turn the elements on and off and as such when they fail they generally disconnect power or refuse to turn on the elements. On very limited occasion though, they fail by fusing together and therefore the element connected to them is powered even if the control is not running a program. So as a result, if you were to touch an element with a fused relay failure you would get shocked. If your conductive shelf was touching that element and the relay failed fused then touching the shelf presents a risk of shock.

I believe most kiln manufactures already  protect themselves by suggesting to remove all power to the kiln while loading / unloading,  limiting their liability and protecting themselves from the occasional fused relay failure. Heck, just put a note in the operation manual suggesting to remove all power.

So to answer your question, always a good idea to shut off your kiln while loading / unloading and a good safety precaution if you have bonded nitride shelves. Great that you have a disconnect to do this with!

[neilestrick]

If a relay was fused in the on position, the kiln would be too hot to unload anyway.

[Bill Kielb]

10 minutes ago, neilestrick said:

If a relay was fused in the on position, the kiln would be too hot to unload anyway.

Depends on how many elements are active actually. It is usually accompanied by an error to which  I have seen this happen and folks had their hands in the kiln trying to figure it out.  The point is, it’s still a shock hazard. The other side of that is when one set of the double pole relay is fused  and the other opens so no heating but don’t touch that element, it’s live!

 

[neilestrick]

35 minutes ago, Bill Kielb said:

Depends on how many elements are active actually. It is usually accompanied by an error to which  I have seen this happen and folks had their hands in the kiln trying to figure it out.  The point is, it’s still a shock hazard. The other side of that is when one set of the double pole relay is fused  and the other opens so no heating but don’t touch that element, it’s live!

 

Well that's just not smart. If you're doing repairs on a kiln, you should never touch the elements with the kiln plugged in, and there's absolutely no reason to touch the elements anyway until you've checked out everything in the control box with a meter, and have then unplugged it.

Whether one element or two or three, if the element was full on for more than 5 minutes there would be more than enough heat coming off it that you would know it was putting out heat, and you wouldn't get near it with your hands. If it was on for 10-15 minutes it would be glowing.

I have seen one side of a relay fail, which would cause an error code, which takes us back to you should never touch an element with the kiln plugged in, etc. The odds of touching an element that has power to it are very, very low. However, I agree that all of these scenarios, however unlikely, can be avoided by simply disconnecting power to the kiln when you're loading and unloading it.

[liambesaw]

Is the only danger of electrocution? Or is it possible to damage your elements as well?  Not sure which is worse (just a joke)

[Bill Kielb]

19 minutes ago, liambesaw said:

Is the only danger of electrocution? Or is it possible to damage your elements as well?  Not sure which is worse (just a joke)

There is a small danger that if you really lean the shelf  against enough of the element and it is connected well that it will short that portion and make the element run a little hotter. Even if  there was a way for the shelf to short one leg to another the machine is protected from overload so blown breaker, no fire. Other than that,  electric shock is the biggie.
 

The proper advice is turn it off, all kiln manufactures tell you to do that (see L&L below)  because the possibility exists. Speculating on probabilities is fine and speculating on whether it is 12 hours later and cool is fine but really people do what they do, usually by accident or don’t know better or have not been taught of the risk.

I can’t remember seeing anyone turn off their kiln to load or unload actually. I think silicon carbide bonded  nitride shelves carry some additional risk but if you use them in an informed way little if any additional risk.. Maybe we should stop using silicon carbide in our glazes? (Just kidding)

[liambesaw]

Well the saint gobain page on advancers just says to not use them if a kiln has slumping or bulging elements, I'll go with that!

I would love to get a set of cheapos, since they're about the same price as the 1" mullite shelves, but I have so many mullite shelves that magically cracked in half that I think I'm set for a few years.  I'll probably retire them as they continue to spall and replace them as they go.  I am a bit sad that saint gobain seems to be the only brand gutsy enough to make octagon and decagon  ones at 20 inches, because of course they're the most expensive (170 for a half shelf, 260 for a full!!!) I'd have to be able to come to grips with the fact that they're 6 times the price and will never make financial sense.

[Bill Kielb]

9 minutes ago, liambesaw said:

Well the saint gobain page on advancers just says to not use them if a kiln has slumping or bulging elements, I'll go with that!

I would love to get a set of cheapos, since they're about the same price as the 1" mullite shelves, but I have so many mullite shelves that magically cracked in half that I think I'm set for a few years.  I'll probably retire them as they continue to spall and replace them as they go.  I am a bit sad that saint gobain seems to be the only brand gutsy enough to make octagon and decagon  ones at 20 inches, because of course they're the most expensive (170 for a half shelf, 260 for a full!!!) I'd have to be able to come to grips with the fact that they're 6 times the price and will never make financial sense.

Did you check Axner for the knockoffs. At one time I think I could find our shapes there. Not super smooth, pretty flat but not like the pressed stuff but really good I think. I  calced it out one time and even with those, we reduced the kiln mass a significant percentage. I think at least 20% if not 40% actually. I used to joke I am tired of firing shelves, they look basically the same every time why am I wasting energy  to heat shelves?

Oh, none of my kilns have elements that come out, when they start I take a torch and put them back and pin as necessary. Takes a couple minutes of effort.

[liambesaw]

27 minutes ago, Bill Kielb said:

There is a small danger that if you really lean the shelf  against enough of the element and it is connected well that it will short that portion and make the element run a little hotter. Even if  there was a way for the shelf to short one leg to another the machine is protected from overload so blown breaker, no fire. Other than that,  electric shock is the biggie.

Do you think electricty in our kilns is ever sad that it can't reach ground?  I kind of figured it wouldn't short or burn up, I can't imagine SiC being MORE conductive than the actual element, but I've been a dummy before!

[Bill Kielb]

8 minutes ago, liambesaw said:

Do you think electricty in our kilns is ever sad that it can't reach ground?  I kind of figured it wouldn't short or burn up, I can't imagine SiC being MORE conductive than the actual element, but I've been a dummy before!

I agree, liquid dripping glaze is often pretty conductive anyway. Hard to short out meaningfully regardless so pretty remote possibility. Don’t put any shelf against your element, the element will overheat anyway. Contactor and lid switch adds a lot of practical safety to any kiln actually for typical users. Wonder when they will require them here.

as to sad, maybe angry (Pixies)

[liambesaw]

9 minutes ago, Bill Kielb said:

Did you check Axner for the knockoffs. At one time I think I could find our shapes there. Not super smooth, pretty flat but not like the pressed stuff but really good I think. I  calced it out one time and even with those, we reduced the kiln mass a significant percentage. I think at least 20% if not 40% actually. I used to joke I am tired of firing shelves, they look basically the same every time why am I wasting energy  to heat shelves?

Oh, none of my kilns have elements that come out, when they start I take a torch and put them back and pin as necessary. Takes a couple minutes of effort.

I have checked axner before, but with the "special packing fee" and the shipping they're almost as expensive as advancers from my local pottery supply.  The price sure looks good before the add-on fees though!

[liambesaw]

Whoa I just checked and SPS has generic 21 inch half shelves for 50 bucks...  Ok, I'll have to start buying them as mine wear out then, that's only twice the price of a normal half shelf.  Wish they had full shelves

http://www.seattlepotterysupply.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=sps_ecat&Product_Code=31268&Category_Code=NBSCS

[Bill Kielb]

Just now, liambesaw said:

I have checked axner before, but with the "special packing fee" and the shipping they're almost as expensive as advancers from my local pottery supply.  The price sure looks good before the add-on fees though!

Axner was bought by Laguna so I think we were able to get creative and ship with a clay order. Always could be a vacation to Disney to see some pixies and stop at Axner. I stopped and got the tour when I was there just to look at the shelves several years ago. Nice people!

[liambesaw]

1 minute ago, Bill Kielb said:

Axner was bought by Laguna so I think we were able to get creative and ship with a clay order. Always could be a vacation to Disney to see some pixies and stop at Axner. I stopped and got the tour when I was there just to look at the shelves several years ago. Nice people!

My uncle is a glass furnace engineer for saint gobain, wonder if he can get me a discount haha (not likely)

[Bill Kielb]

1 minute ago, liambesaw said:

My uncle is a glass furnace engineer for saint gobain, wonder if he can get me a discount haha (not likely)

Really, Really nice  shelves 1/4” maybe 5/32 nds ! Super smooth! I would try hard for that one. C’mon uncle!

[Dick White]

6 hours ago, Kakes said:

Thank you for your answers, Dick White. When you say "be careful to mount them where they are between elements.", do you mean that they shouldn't line up with a row of elements? Is this generally true with kiln shelves? I thought I just had to be careful of the thermocouple. I'm using a top loading electric kiln. This is my first year and I'm learning by doing!

It is my opinion and practice that shelves should always (if possible) be arranged so that they are between rounds of the elements. You want the elements to be heating the wares on the shelf, not the edge of the shelf. This is particularly important at red heat and above. At those temperatures, the heat is transmitted by radiation, not by convection. The elements are the source of the heat in the kiln, and should be exposed to the ware.  And yes, you need to build around the thermocouple(s) too.

[Mark C.]

On 12/27/2019 at 10:41 AM, Kakes said:

Hello, I just spent a couple hours reading up on Advancer shelves including all the posts here that came up on the search. I still have a few questions I'm hoping some of you might be able to answer  before I bite the bullet and spend the $$$.

I fire large stoneware slabs (up to 20") flat on small stoneware rods (1/4" diameter) to prevent cracking. Warping doesn't matter so much. Will they do anything different on Advancer shelves? Could I stop using the rods?  Right now I have the regular solid cheap shelves - forgot what they're called. 

Also, I have a downdraft vent on my kiln (skutt). Is this ok with Advancers? 

Trying to decide whether to wash the shelves -- I only use stoneware, which seems like it's ok not to wash. Do the shelves need to be flipped? (I hate messing with kiln wash, especially the clean up of shelves.) 

And finally, do I need to wash the ends of my kiln posts? I've never done this before, but I thought I read that it's a good idea with the advancers.

Thank you!

Kakes I fire about 60 advancers in a few GAS kilns about 50-60 fires a year(glaze fires and as many bisques as well)-I had a friend who used them also in his electric with a vent.He fired porcelain so he washed his with our high alumina homemade wash-do not use commercial wash (its crap)He fired to cone 9 in that electric.

1st off since you are using an electric I'm assuming you are firing mid range as you do not mention temps at all. This is a key factor on advice from me.Let us know what temps you are firing to?

Lets assume you are a cone 5-6 er .The advancers and stonewares do not stick or Pluck. I fire to cone 11 and use all porcelain so I wash my shelves you will not have to.Porcelain will stick and pluck. Now as to the slabs and youre rollers as thats whats working for you now. The same will be true with any shelve as its the flat slab mass thats dragging across the surface. any surface The only gain with advancers is they are dead flat. That may help you some but the only way is to try one without the rollers-my guess is the rollers are needed.

Now the big gain with advancers is the space savings-if you fire alot they pay for themselves very fast in terms of space saved

yes you can use a vent but keep in mind they do not like thermo shock but most electrics do not thermo shock wares or shelves at all.They are more even temps than gas kilns.Sinve you are fioring large slabs you will also never thermo shock thema s they would also break so thats a non issue.

No need to flip an advancer as they stay perfectly flat forever and cone 6 is really not that hot for them-mine at cone 11 for 60 fires a year since the 90s are still flat as the day they came.

Now lets talk money-since you are only firing to come 6 (this is what I'm guessing) you just needd the cheapest flat shelve you can get-advancers are great but the Bailey shelves from Germany tend to cost a small amout less and I have tested them for some years now and they are just as good as advancers in all ways. The corners are a bit more rounded on the German ones

But wait theres more-you can buy thru Laguna clay (Axner in the east or Laguna in the midwest (Ohio and far west) the cheaper Chinese knock offs-they are slighly uneven )meaning say they may be 3/16 at one end and 5/16 at another end-they are much cheaper and since you are only firin g to cone 6 they will hold up well for a long time(they warp at cone 10 over time but at cool cone 6 you should get lots of years from them. If you are in a commercial situtaion like me I woulkd spend the funds on the German ones thru Bailey but if its not your living the cheaper knock offs will work fine.The surface is more course on these cheap shelves and they are more irregular all the way around but they are cheaper by a long shot

If you told me how much in a year you fire this may affect my recommendations  as its a unknown -more info would help me-is it yiour living or a hobby??

The last question you had is washing the post ends and thats a yes some wash will keep them from sticking-always a good idea-so thats a YES wash the tops and bottoms-I dip mine.

The best wash I have found is this formula  - 1/2 alumina hydrate ,1/4 calcined EPK, 1/4 EPK-calcined means bisqued-you can do that in any form in any bisque fire your self or you can buy it bisqued and its called glomax. Mix with water to heavy cream consistency-I use a 3/8 nap paint rollor to apply a smooth flat surface-I heat my shelves in sunlight and when 1st coat is dry I roll the second coat-I use a knife to cut the slop on shelve edges whei it drys. I get years of use without rewashing (at least 75-100 glaze fires)This wash can be knocked off 100% as well if you want a clean surface again.

 

Now in terms of avoiding the stack on the elements level as Dick White said well thats all  very true in a perfect world

For me as I only do some slight bisquing in my 10 cubic elctris (say average 10 fires a year) I usually biuque in my 35 cubic car kiln

I tend to put as much pottery as I can cram into the kiln with zero regard to where the shelves line up,usually its  all say mugs or  glasses or whatever and seen no ill effects from that use . I do not glaze fire in electrics .I have never given the shelve to elements a second thought as the only thought is get as much in as possiable  as my electric rates here are to the Moon.This is a living for me so filling the kiln with zero wasted space is a key thought which is true with all my kilns.Been doing this for 40 plus years in my electrics and gas kilns .

Now as to all the talk about advancers or any recystalized silicone carbide shelve  and elements and electrucutioin-just a little common sense-do not let them touch the elements, If your elements are bulging out of the brick grooves fix them  as they need fixing anyways then use the shelves. No big deal

The last point is keep these shelves dry which you should be doing with all kiln furniture anyway. They are subject to explosion if fired wet and to fast for steam to escape.. I tend to wash my shelves then fire them in  a slow bisque cycle with pots first before a glaze fire-never blew any up but I know  a story about an idiot (potter)who hosed his shelves down with a garden hose and fired them in a glaze fire and blew op the whole load-but it was the guy not the shelves who was the problem-everyone knows a person like this in life.

I think I covered all your questions with the info you gave us.Hope this helps your decision making.

Mark

 

[LeeU]

 

4 hours ago, Mark C. said:

cheaper Chinese knock offs

I was saving my pennies for Advancers (due to a pesky-and sometimes painful-lack of lifting/holding strength in hands/forearms) but spendoolies are a big issue, given my low production volume and infrequent firings, compared to most potters here. I will absolutely look into the Bailey's (great company/people) and even the Chinese.  Thanks for the info. 

Oh-I just went to Axner & Bailey's sites.  I am now thoroughly confused. We have at Bailey shelves such as Oxide Bond, Corelite and Thermalite. At Axner we have Cordierlite, and Nitride Bonded Silicon Carbide.   Which--as an economy version similar to Advancers--are you referencing? Thanks.

[Bill Kielb]

4 hours ago, LeeU said:

 

I was saving my pennies for Advancers (due to a pesky-and sometimes painful-lack of lifting/holding strength in hands/forearms) but spendoolies are a big issue, given my low production volume and infrequent firings, compared to most potters here. I will absolutely look into the Bailey's (great company/people) and even the Chinese.  Thanks for the info. 

Oh-I just went to Axner & Bailey's sites.  I am now thoroughly confused. We have at Bailey shelves such as Oxide Bond, Corelite and Thermalite. At Axner we have Cordierlite, and Nitride Bonded Silicon Carbide.   Which--as an economy version similar to Advancers--are you referencing? Thanks.

I can attest to the knock offs from Axner. They have been  fired at cone ten for about two years with good result. Also visited a Potter in Orlando that used them prior to our purchase decision and he had many firings on his. Part of what convinced us to try them.