Hulk

Hi Dot,
Welcome to the Forum!
Crazed wares, almost certainly weaker*, and liquids can be a concern, particularly where the fired clay's absorption rate is "high"...
For sculpture (and other non-food ware), however, crazing may be ok?
Reversing crazing, that may not be possible.
My understanding is that crazing occurs when the clay and glaze COE** are different enough, and that can only be corrected by changing the glaze and/or clay.
If the clay matures at a higher cone (than 04, in your case), the fit may change when fired higher, but not necessarily a better fit!
Check back for more responses...
 
*A well fitted glaze makes for stronger ware
**Coefficient Of Expansion
Co-efficient of Thermal Expansion (digitalfire.com)
see also Mr. Hansen's articles on glaze crazing, glaze fit, glaze compression 

Wheel vendor hp ratings may not be equal.
The Skutt hp ratings are "continuous duty"...
The "pounds of centered clay" ratings also may not be equal.
Last sentence on Skutt's "Motor" webpage*: "Most people will be fine with a 1/3 HP motor, but, if you are throwing big stuff you might want to step up to the 1/2 HP or 1HP motor."
I'd agree with that, err, with edit to "...lots of big stuff for a long time, you might want to step up..."
My 1/2 hp model, maybe it's "broken in" by now, after six years?
Both are good wheels!
*The Motor - Kilns | Ceramic Pottery Kiln, Glass Kiln, Pottery Wheels | Skutt
 
Added: Looks like Skutt has changed their product line; I'm not seeing which models have the 1/2 or 1 HP motor.
My Stephen Hill (~2016) is fitted with a 1/2 hp motor; its twist is something to respect, for sure...

Well I ended up emailing Rob Battey as suggested. Think I’m going to end up with the L&L e23T-3 with quad elements and vent sure system. Thanks again all!

Thanks again everyone, I ended up going electric for now!

I Have only been in An Olympic gas kiln for the past 30 years. We installed a tankless H2O system, and our pressure is now been upgraded to commercial levels. I can easily overfire the Little Beast. I've had a couple of cone 11 cones puddles. I’m Doing a bisque Fire Now with a full load of heavy and big fermentation crocks. I started at noon yesterday  and Will finish up at about 03:30. At 1800 Now.
William
The Kracked Pot,
Washington NC

It a tricky one to decide, will the initial cost to get an electric kiln up and running save you money in the long term with lost ware and time you could be doing something else. 
 
I have semi automated a gas kiln adding a controllable valve onto the pipe but that is not the easiest thing to do. It just meant instead of turning it up every 20 minutes the computer did that for you. There was no brains really, the first firing I did have to turn it up via the computer and record what was set and run a simple program to repeat that for me the next firings.

Bill and Neil, it seems I have to ask myself how much time I want to spend while firing. Based on the information, I am going to talk to a potter who knows a bit more about gas kilns than I. Thank you very much.

High Bridge Pottery, they said because the gas kiln does not come with a controller, I have to watch the temperature rise very closely. Because I am firing pieces I have spent more than 10 days on, they wanted me to go safe. The 3 responses above are telling me I can bisque in a gas kiln, and I am willing to learn how to do it. Before deciding which kiln to get, I am going to get bids from contractors. Thank you very much.

I haven't seen that, and would be interested if you have a ref.
But I have seen occasional references to needing to let the pot dry sufficiently between glazing one surface and the other.
... this seems to be more of an issue with dipped glazes than painted ones.

Yes, mostly ought to be fine. One color can influence another a bit I suppose on occasion but folks use liner glazes different than their exterior glaze all the time. Folks often dip their tiles … 3 second, 5 second dip …. 1 coat, 2 coats. So using test tiles and brush applying each side has its drawbacks.
With respect to glazing the outside and not the inside or Vice versa this can create an unbalanced stress in the clay as the glaze often squeezes the clay so to speak. This tiny bit of compression can increase the strength of the ware significantly. So one side glazed and the other not can cause unequal stress in the ware. End result - more fragile ware occasionally breaking suddenly when someone puts hot coffee in a cold mug for instance. Fully glazed well matched - glaze and clay- generally enhances the durability of the ware.

Any relevance?
https://digitalfire.com/material/gerstley+borate
... at the bottom of the page, discussing substituting  Gillespie Borate  for Gerstley Borate ...
Clearly, the Floating Blue itself is firing greener than usual. And the Gillespie Borate version is much bluer. You may be used to something in between these two. The green tones could likely be restored by a reduction in the cobalt and increase in the iron oxide.

Min - Rather than use roof flashing I use thin plastic sheeting. (I was working at a large corporation, years ago, and they were transiting away from thin plastic sheets, to protect desk tops, to a formica desk top, so I collected lots of thin plastic sheets.)
While the plastic sheets are nice, when I mold round forms, (as opposed to a square pouring box) I sometimes forget that they need to be held down, at the bottom of the shape, as well as strapped together, at the top of the shape, to prevent the whole thing lifting up. (and covering my shoes and pants with a thin layer of plaster splatter.)

Thanks Peter for the links! I actually have been thinking about exploring slow cooling as well as putting things in saggars to get reduction effects.  I am sure I can figure out ways to get glazes I like in an electric kiln… just won’t be quite as straight forward as doing it in a gas kiln…

If you are leaning that way have you explored slow-cooling in an electric kiln? Which can have a dramatic effect on some glazes.
PS Some eye candy.

https://ceramicartsnetwork.org/daily/article/Super-Cool-Slow-Cooling-in-an-Electric-Kiln

 
https://cone6pots.ning.com/forum/topics/slow-cooling

 
https://ceramicartsnetwork.org/daily/article/Tips-for-Increasing-or-Decreasing-Crystallization-in-Glazes
... same glaze fired in a gas kiln: with the "natural" slow cooling of a gas kiln & with a "crash" cooling similar to that usually given by an electric kiln.

https://digitalfire.com/schedule/c6dhsc
https://digitalfire.com/picture/bestenazoh

https://digitalfire.com/picture/3348

 
A  discussion on iron reds in this thread
http://ralpotterystudio.blogspot.com/2010/08/new-glaze-tests-710.html
... a fairly mixed bag, including

Previous firings of this glaze at cone 6 or less without slow cooling produced dark browns. This is one that really requires slow cooling to get the red appearance, but proves you can get red reds at cone 6.

Hi Steph and welcome to the forum.
Linda Arbuckle pdf with a good recipe on page 4. What is helpful from this pdf also is the troubleshooting tips on page 3. 
https://www.lindaarbuckle.com/handouts/slips-and-engobes.pdf
Which brands and colours are burning off? 

The Ceramic Shop online sells some parts.  You can get the wheel pulley, part 13, as well as a new wheel head which comes with the bearings, which I was told are parts 1 and 2.

karo, hope the wheel is still available for you to buy.   looks are only important to a fashion model.

as i get older, i wish i had a "wheelie bin".    wanna trade for my circular dragitouttothestreet one?

A roof top satelite dish make a good drape mold for a birdbath.    Denice

Trimming feet for almost everything, hence I leave clay for that at the bottom, also, wiring off, quite often, leaves a step.
I'll wire off when the top portion is stiff enough to handle, then set the pot on a plaster bat to dry out the bottom.
So, once set up to trim, after the first pass, I'm using the needle tool to establish level (height) and round (width) foot ring.
The needle tool goes right in - it doesn't follow the contour of the work.

Well Pres, that sounds slick!  I think I need a visual!

QotW: How do you level the bottoms of thrown pieces?
I have been working on some chalices lately, trimming the bowls and the stems before joining and got to remembering how . . . . in the day I would use a needle tool to the level pieces up, whether the were thrown off the hump or on a other wise. In the first days of learning to throw I threw on the venerable Randolph motorized kick wheel with the cup heads where a plaster bat would fit for throwing. They were marvelous as the next day things would be dry enough to remove and trim and then move on. Then came working with metal wheel heads, and trimming of and removing the pots from the wheel or working on a wooden bat. Seems I always got things a little wonky and out came the needle tool to even small things up. Then at Penn State someone introduced me to the hack saw blade held perpendicular to the pot held by both hands to level the pot. . . Wow!  To this very day, any throwing with leveling needed is done in the same manner. Double that if throwing off the hump, as I whip out 20 cups in an hour and worry about level in the trimming. Same works for plates as 12" of surface with a cutting wire is not always level!
QotW: How do you level the bottoms of thrown pieces?
best,
Pres

Here is a picture…
IMG_0370.pdf

Do you know what the specific gravity of the glaze is that you did the one dip of? How long did you did it for? Have you tried a much thinner coat of the same glaze?
Amaco does publish a colour chart with all their Velvet underglazes fired to 05, 5 and cone 10. If you scroll down to the blacks it looks like both the Jet and Velour Blacks survived cone 10. From the little inset blurb about clay and glazes used it appears that HF9 was used on both the cone 5 and cone 10 samples. If you try this commercial glaze please do check with Amaco on this as this is actually a cone 5 glaze.
https://cdn.shopify.com/s/files/1/1023/7667/files/Velvets_Underglaze_all_temps_brochure.pdf 

the word "dust" is misleading.   ordinary household dust is bad enough but pottery making involves many chemicals, well, minerals, that are toxic to the lungs.  when in the powder state, silica is the main culprit and handling it carefully while wearing a respirator provides the safest way to use it in a home studio. 
keep a damp sponge near any handbuilding area and use it all the time.  no work surface should be covered in dry clay.   and tossing tons of water at the piece  while working at the wheel is just silly.  only your hands need enough  water to control the clay.  cleanup is so simple if you do not make a mess in the first place. 
sloppy working conditions are not necessary in any studio.  keep it as clean as you would like your lungs to be when you die.