a few more questions re Advancer shelves...

[neilestrick]

Here are some rough numbers on buying Advancers vs Corelite shelves. These are all just estimates, since firing costs and other factors will vary greatly. Let's say you've got a 27x27 round electric kiln like a KM1227 or E28T that costs $20 to fire. A typical kiln load of mixed work will have 6 layers of shelves if you make a lot of mugs and small bowls. Advancers are 5/16" thinner than a Corelite shelf, so you're going to save just under 2" in height with every load. That means you're getting about 7% more work in per load, or in other words one less firing needed every 14 loads, or an average of $1.40 per load. If you fire a lot of taller pieces and use fewer shelves, like only 3, that number is going to go down to a point where the space savings is negligible. Round Corelite half shelves actually weigh about the same as Advancers, so you're not getting any savings there. 

A 26" half round Corelite shelf costs $55, and an Advancer costs $185, so $130 difference per shelf, or $1560 for the 12 half round shelves needed to fill our kiln with 6 rows of shelves. $1560 divided by the $1.40 savings per load means it will take 1,114 loads for the shelves to pay for themselves. That's within the expected life of a round kiln, so the shelves will pay for themselves within the life of the kiln. But if you're a hobbyist that fires two loads of pots per month (4 firings- 2 bisque & 2 glaze), it will take 23 years. This is also assuming that you actually are able to take advantage of the space savings in every load. For many loads you won't.

I think the biggest issue with buying Advancer shelves is the up-front cost. For me to buy enough Advancer shelves for my large electric (21 cubic feet), it would cost me over $4500, plus crating and shipping which would be about $500 more. Corelite shelves would cost me $884, and I can get them locally. $4000 is a big deal.

I've had a set of 14"x28" Corelites for 7-8 years now, and they're still as flat as the day I bought them, and I've never flipped them. I would save about $500 a year on firing costs by using Advancers, which to me isn't worth it. Selling 14 more mugs every year would give me the same money, and the $4000 could be used for marketing or studio improvements that would be much more profitable in the long run.

So are Advancers worth it from a financial standpoint? They'll certainly pay for themselves over the life of the kiln. Will they pay off quickly enough to make the up-front investment worthwhile? For a production potter, yes, especially if you've got a large, tall kiln where the height savings really come into play and you fire several times per week. For a semi-production potter like me, probably not. For a hobbyist I would say no, especially with the risk of breakage.

Do I want Advancer shelves for my kilns? Absolutely! They're totally sweet!

[neilestrick]

About 12 years ago I bought some of the knockoffs that have the slits in them, and they were junk. They all warped at cone 10, and continued to warp more at cone 6. I don't know if they're still the same formula that they were back then, though.

[liambesaw]

I'm gonna give the knock offs I can get locally a try since they're cheaper than the corelite ones.  My solid mullite ones are not good.  They break.  I've had them crack in half in less than a year so if the knockoff advancers are durable, it will be a savings for me there.

[Bill Kielb]

3 minutes ago, liambesaw said:

I'm gonna give the knock offs I can get locally a try since they're cheaper than the corelite ones.  My solid mullite ones are not good.  They break.  I've had them crack in half in less than a year so if the knockoff advancers are durable, it will be a savings for me there.

If you are using solid mullite then you will save mass and energy. Saving space by height is a tough one because it’s rare folks pack that tight to assume the gain in area can be realized.  In the studio we have too many different height wares.
 

The Corelites are great but glaze still sticks to them which is a pain or means kiln wash and they don’t tolerate a bunch of grinding. I think you will like the freedom and energy change from mullite.  Best case 40% lighter, worst case 20%. Imagine the difference in firing a kiln loaded 60% vs 100%. Very significant. What happens actually is your firings begin to match the schedule more closely as your kiln now effectively has more power.

The end result is more on schedule firings and less standby losses waiting to get to temperature and a funny side benefit is you can get more firings out of a set of elements before they can’t make temperature and must be replaced. Payback realistically is mostly energy saved and dependent on cost per kWh. Payback in the studio is energy but top of the list is grinding time, labor and material to kiln wash, opportunity time as they are drying (what a pain!) 

[liambesaw]

8 minutes ago, Bill Kielb said:

If you are using solid mullite then you will save mass and energy. Saving space by height is a tough one because it’s rare folks pack that tight to assume the gain in area can be realized.  In the studio we have too many different height wares.
 

The Corelites are great but glaze still sticks to them which is a pain or means kiln wash and they don’t tolerate a bunch of grinding. I think you will like the freedom and energy change from mullite.  Best case 40% lighter, worst case 20%. Imagine the difference in firing a kiln loaded 60% vs 100%. Very significant. What happens actually is your firings begin to match the schedule more closely as your kiln now effectively has more power.

The end result is more on schedule firings and less standby losses waiting to get to temperature and a funny side benefit is you can get more firings out of a set of elements before they can’t make temperature and must be replaced. Payback realistically is mostly energy saved and dependent on cost per kWh. Payback in the studio is energy but top of the list is grinding time, labor and material to kiln wash, opportunity time as they are drying (what a pain!) 

Meh I can count on one hand the amount of times I've had to grind a shelf, but the rest sounds good.  Biggest savings will be not having to replace them as often!  I only have an 18 inches tall kiln so I'm usually max 3 shelves unless I'm doing plates or something.  Doubt the extra inch will do much for me lol

[Bill Kielb]

2 minutes ago, liambesaw said:

Meh I can count on one hand the amount of times I've had to grind a shelf, but the rest sounds good.  Biggest savings will be not having to replace them as often!  I only have an 18 inches tall kiln so I'm usually max 3 shelves unless I'm doing plates or something.  Doubt the extra inch will do much for me lol

I think you will like them. In the studio there can be lots of grinding! Funny you brought up plates, If ya ever fire a kiln load of plates or low  height objects - schedules tend to run much longer as well. Especially if packed with lots of heavy mullite shelves. If you get em you will have to let us know what you think.

[Mark C.]

OK Kiln shelve dot com carries advancers (thats who I have bought at least 40 from since the 90s)-gtreat shelves-

look here-https://kilnshelf.com/kiln-shelves/advancer-for-top-loading-electric-kilns/

Baileys carrys the Thermo-lites-also great shelves-

https://www.baileypottery.com/c-168-21-516-f.html

Baileys also carries the cheaper knock offs nitrated bonded SIC shelves for electrics

herehttps://www.baileypottery.com/store-dept-gas-electric-kilns/store-kiln-furniture-and-accessories/store-kiln-furniture-and-accessories-kiln-shelves.html?gclid=EAIaIQobChMIz7mS-Mzb5gIVgYbACh2hlQvdEAAYASAAEgJiHvD_BwE&p=2

Axner carries the knock offs as well here

https://www.axner.com/nitride-bonded-silicon-carbide-kiln-shelves.aspx

 

One thing I will mention is a general lack of knowledge in the kiln furniture area for many potters-they just call them shelves and have no idea of what tney are made of this is especially true with folks who fire electrics only.

I have posted many a post on shelves and the various types-search for them to learn about shelves

So a few points I did not cover in my post to original poster-the glass smooth advancers as well as the Bailey Thermo lights-(you can tell these se shelves as they are very costly_) resist

all glaze drips-that means glaze does NOT STICK to them ever. The surface of shelve is glassy smooth

The chinese shelves (cheaper knock offs) do to some degree absorb glaze  as the surface is a bit rougher and grainy.

Also if you are firing to cone 10 the knock offs will warp over time-Mine tester ones are now cracked and banana curved -I like to test shelves like i tested the Baileys for you a few years ago and posted the results-Now that Bailey is in the quality shelve market the price has dropped from both distributors as there is competion. For many decades Advancers whgere the only shelve of this quaility and the price kept rising-I always bought in groups of 10 for price breaks but now thats long gone. These 12x 24 (a stanadrad size in gas kilns for 60 years) was 100 when i fisrt bought Advancers and climed to over $200 per shelve now its dropped with two manufactures .

One lastr note all of these shelves do not like thermo shock and as potters youi shoulkd know this term. Its when you quick cool or shock a item from cold to hot or hot to cold.

Just put one of your pots  ( a junker pot )over a gas burner and turn on the gas and watch what happens -its uneven heating where the bottom of pot is hot and the top is cold bingo thermo shock-pot breaks-well this is an extreme lesson but quik cooling and uneven cooling  (as well as a few other principles that one needs to know like flameproof body )with these tight grained shelves is not something you should do to them.They are tighter grained than your typical mullite based low fire kiln shelve and cannot take thermoshock as well.

 

 

 

[Mark C.]

15 hours ago, neilestrick said:

Here are some rough numbers on buying Advancers vs Corelite shelves. These are all just estimates, since firing costs and other factors will vary greatly. Let's say you've got a 27x27 round electric kiln like a KM1227 or E28T that costs $20 to fire. A typical kiln load of mixed work will have 6 layers of shelves if you make a lot of mugs and small bowls. Advancers are 5/16" thinner than a Corelite shelf, so you're going to save just under 2" in height with every load. That means you're getting about 7% more work in per load, or in other words one less firing needed every 14 loads, or an average of $1.40 per load. If you fire a lot of taller pieces and use fewer shelves, like only 3, that number is going to go down to a point where the space savings is negligible. Round Corelite half shelves actually weigh about the same as Advancers, so you're not getting any savings there. 

A 26" half round Corelite shelf costs $55, and an Advancer costs $185, so $130 difference per shelf, or $1560 for the 12 half round shelves needed to fill our kiln with 6 rows of shelves. $1560 divided by the $1.40 savings per load means it will take 1,114 loads for the shelves to pay for themselves. That's within the expected life of a round kiln, so the shelves will pay for themselves within the life of the kiln. But if you're a hobbyist that fires two loads of pots per month (4 firings- 2 bisque & 2 glaze), it will take 23 years. This is also assuming that you actually are able to take advantage of the space savings in every load. For many loads you won't.

I think the biggest issue with buying Advancer shelves is the up-front cost. For me to buy enough Advancer shelves for my large electric (21 cubic feet), it would cost me over $4500, plus crating and shipping which would be about $500 more. Corelite shelves would cost me $884, and I can get them locally. $4000 is a big deal.

I've had a set of 14"x28" Corelites for 7-8 years now, and they're still as flat as the day I bought them, and I've never flipped them. I would save about $500 a year on firing costs by using Advancers, which to me isn't worth it. Selling 14 more mugs every year would give me the same money, and the $4000 could be used for marketing or studio improvements that would be much more profitable in the long run.

So are Advancers worth it from a financial standpoint? They'll certainly pay for themselves over the life of the kiln. Will they pay off quickly enough to make the up-front investment worthwhile? For a production potter, yes, especially if you've got a large, tall kiln where the height savings really come into play and you fire several times per week. For a semi-production potter like me, probably not. For a hobbyist I would say no, especially with the risk of breakage.

Do I want Advancer shelves for my kilns? Absolutely! They're totally sweet!

I tend to agree with Neil on most points above except if your electricity cost are to the moon as mine are that changes the equation some. That said I use thin mullite shelves in my 10 cubic foot bisque only kiln as  the space saving is minimal and tumble stacking can help with any size difference. The shelve weight for loading on ones back cannot be a cost factor as much  as they are so much lighter so if you say have a top loader and your back is toast and you can afford them -it makes sense . One last point is the resale on them is always high as they keep value as they never wear or warp or age. I have bought over 20 advancers used in past 10 years (all 12x 24 ) and I paid $110-$140 for them all in groups of 10 or 12. so they keep a good resale value where as mullites have next to zero value over time-just a thought for you considering the upgrade.

[Bill Kielb]

9 minutes ago, Mark C. said:

I tend to agree with Neil on most points above except if your electricity cost are to the moon as mine are that changes the equation some. That said I use thin mullite shelves in my 10 cubic foot bisque only kiln as  the space saving is minimal and tumble stacking can help with any size difference. The shelve weight for loading on ones back cannot be a cost factor as much  as they are so much lighter so if you say have a top loader and your back is toast and you can afford them -it makes sense . One last point is the resale on them is always high as they keep value as they never wear or warp or age. I have bought over 20 advancers used in past 10 years (all 12x 24 ) and I paid $110-$140 for them all in groups of 10 or 12. so they keep a good resale value where as mullites have next to zero value over time-just a thought for you considering the upgrade.

I think Liam has sourced knockoffs that are less than core lights and sold locally. 

[Mark C.]

21 hours ago, Bill Kielb said:

I think Liam has sourced knockoffs that are less than core lights and sold locally. 

Tacoma Art center  or Seattle Pottery for him are the two local places he can get shelves-Tacoma being a bit of a drive south.

We also have a local source that carries a fewi

[liambesaw]

4 hours ago, Mark C. said:

Tacoma Art center  or Seattle Pottery for him are the two lacal places he can get shelves-Tacoma being a bit of a drive south.

We also have a local source that carries a few

Yep, Seattle pottery is 49 for a half shelf of their nitride bonded silicon carbide.  I think 69 for 12x24.  They have a pricier version but they're 23 inch and won't fit my kiln, and they only have full shelves of those.

Gonna just give them a try next time I pick up clay (probably late Feb).  I'm thinking more of durability and less of the other benefits, as I've been disappointed with mullite shelves in general.

[LeeU]

Thanks all, for the expanded info. I'm excited about getting new shelves next year! Probably the nitrated bonded SIC from Bailey. 

[Kakes]

@Mark C. @Bill Kielb and everyone else who responded, thank you so much for taking the time to share your knowledge. I am deeply appreciative. (Sorry for the delay in my response - it's been a long holiday season.) I"m suffering from sticker shock but I'm tempted by the Advancers, mostly by the possibility of never having to deal with kiln wash again and the never warping. BUT - it seems like there are other options that might come close which I hadn't known about til now (thanks again for all this great info! this forum is the best!!)  I will mull over my choices and report back. 

Btw, is there a way to link to a person here without quoting an entire post?

[neilestrick]

3 minutes ago, Kakes said:

Btw, is there a way to link to a person here without quoting an entire post?

If you want to quote part of a post, just quote and then delete the part you don't want, or select the part you want and hit the little button that says Quote Selection. If you just want to tag someone, use @(username).

[Kakes]

@neilestrick got it, thank you.