Babs

Is this toxic workplace making functional pots? 60% lead Bisilicate??? Your making a low fired clear glaze for hopefully non functional ware? Get out of there. Read up on lead posioning. Guess employer not providing sjowering facilities or total protective covering. The occupants of the lead town are called leadheads by the ignnorant. Their brain functions affected to extent the children score WAY below the norm in all aspects of the educational testing. One example only of how lead affects the body. This is from exposure in the wide open. You are in a confined area. Dont tell me you are mixing the powders in a non protected area. Whole place washed down every night.. Laundering at home? You are pousoningbyour family

Ok so grog allows the moisture out freely and so ok.ish.

May become popular as energy prices soar. Did you have to adjust your glaze recipes? @oldlady uses this single firing technique.

The factor of porosity would be key. If the sculpture absorbs moisture , freezes, water expands, you will get a cracking and shearing off. So firing to vitrification would be the way to go. The properties of the clay body which allows you to construct your sculpture best would have to be considered. I think I read of clay additives which when dried allow the forming of minute cracks around each piece whilst being great to increase tolerance of thermal shock may lead to cracking in instances such as yours. @glazenerd may be of help

If the lead is in a fritted form, apart from unsafe env. lead or no lead, would it make a difference?

Absolutely needs reporting!!!! Will affect everybody!! Please be responsible and blow the whistle. Your family will be at risk if you launder at home or wear your clothes home. Children in a town here are tested for blood levels of lead and are not allowed to play in the yards, mums clean houses surfaces 3-4 times a day because of wind borne lead. Don't just get out of there , report it. What ceramics are being made?

Is the glaze recipe available? Does it contain fritted lead? If your employer is not educating you re all dangers when working with lead there is lack of due diligence and could lead to serious health issues. You could be carrying lead home on your clothes and hair. It is absorbed through the skin. Can damage the brain. Hope the ceramic objects are not functional. Lead could leach out of glazes and poison the user. Be careful. Very serious.

you can print silk screen stencils directly from computer , think you need inkjet p for this.

A one of! How valuable is your time? I've noticed ythat newspaper print does transfer onto clay, Could you print, folk will know what printer inks work best, a copy of your image, place on clay, dampen and roll, remove, then paint it with underglazes? Just a thought.

You can make the playgrounds so safe kids wont play in them

If hand building, you could monoprint onto flat clay using a silk screen. Proper registration would get you crisp results.

Damper open creates a draw in from airitakes around burner ports of cold air , so temp will drop??? Yes. Heat will leave kiln esp if the gap under bottom shelf to the flame chamber exists.

Need to run a meticulous logbook for every firing. Time ,hours on,psi reading, temp rise, positionif damper, air intakes.and importantly results of glazes used. Total length of firing. A photo of kiln stacking would be good too . Once you've found your cool spots you can place glazes which don't mind that there. The sculptor may have been only fIring to a low cone. Aftwr you get your bagwall in, don't think your focus needs to be as much on the stacking, but gas, air and damper positions

Indeed. I am thinking the perforated floor and space beneath is equivalent of the space below the lowest shelf in most kilns designs. (NO perforated floor). No bag wall, reopening damper, heat flame sucked across bottom of kiln, temp drop. One big pot or lots of shelves , no matter, keep a log, check everything and write up results hourly.

Yeh well, aussie here, I built a vent above the stack and suspended a flue pipe above the short stack with enough room to operate a damper. It reached up a few fluepipe lengths into the hood then to outside I was firing inside a shed so needed to draw the fumes up into the hood a ways. Fibre kiln. .fired fast up, (only used tge pilot lights for first couple of hours), and dropped down very fast unless sorted.

I am not seeing the flu anywhere. What are your flames looking like as they enter the kiln Think you need to get the bagwall in level with bottom shelf. Direct suck out the bottom if not. Readjusting the airintake after reduction. Reduction all the way, some bodies wont like it, some glazes wont be as attractive... John Eagle had a great article in Journal of Australian Ceramics 2008.

Thinking, maybe, because that floor IS perforated, rhe bottom shelf is ok to be lower as in first photos

From your initial post, are you aware of cone labelling..08 is lower than cone05, like negative numbering . Just saying. I am reading that you thInk differently.

What controller do you have? Whenyou stopped it and restarted it, what ramp did u notice it was displaying? I am thinkinh like Bill, miutes instead of hours entered. Can you flick thro the ramps to see what u entered?

Can you get an old kiln brick and slice it to make a bag wall which will run along level with the bottom shellf? That's all you need. I didn't stagger shelves but space around them and down the middle I did have. Can you contact the prev owner, or put a shout out for anyone with experience with this type of kiln? Remembering, I also put the shelves smack against the outlet side of the kiln...my thinking was to not allow the flame to shoot down there and out of the kiln fast. Change one thing at a time I guess.

There's always a block and tackle!!! At least with top loader the weight is quite close to your body. I worked with a front loader at school, aside from the physical grunt I prefer looking down on my loading,so top loader it is. The feet come off the floor a bit as I shrink.

Well adjusting the air flow to produce reduction has made the air circulate to the outlet in a less direct path????less suck straight up the chimney so heat interior rises????? But requires more adjustment to bring about reduction????? Just thoughts from s.one missing their gas kiln:-) I guess you could put an old shelf over most of the floor to block off the suck????

I feel you need a bag wall along the kiln level with the lower shelf after you raise it a bit. It isn't weird that the temp goes up when you alter the air intake and close off the damper. Playing with this can be key to temp rise after other adjustments made. How high is your stack? Lots of years since i fired with gas but these points come back as pertinent.

Who are the makers? May not need an expensive test. Contact the owner or maker. Portakiln?? Should be a descriptive label s.where. That sag will worsen with age, dropping bits onto your ware, and you'll end up inhaling it. I ended up propping up the top of my kiln with an old shelf, mine was a top loader. Better to get a piece of ceramic fibre board as you may have to dismantle to realign or replace bricks. Is the first photo the door?it doesn't look too bad. Find out if you can paint or spray it with something to stabilize it.