Platter issues

[oldlady]

ron, since your clay is so wet, try rolling it out early in the day and setting it aside for several hours until you can feel that it is dry enough to work correctly.    flipping it off whatever you use to run it through the slab roller and onto a piece of drywall and covering it with another drywall piece will make it go faster.    it is a real pain to do so but it will work.   do not worry about getting it too dry, a wipe with a damp sponge will soften it back up if you overdo the drying.

i know exactly what you mean.  my clay has changed and not anything like the stuff i bought before 2016.  i am using the second last bag that has been sitting around drying out for all that time.   it is finally working right.   i have no idea what i will do once the last bag is gone.

put some bleach into your reclaim so it will not smell so bad.  it doesn't take much.     use reclaim for throwing until you regain confidence in your ability to use it well.

[terrim8]

I've had some issues with various plainsman's clays too lately - some too dry, some too wet. Wonder if they are having production problems?

[Mark C.]

 This is the whole method used in my studio for making large forms on plastic forms-its my birthday and I am drinking coffee so I'll take the time to tell you what I have learned on this.

Recalaim needs slip from your throwing splash pan to help it .It is not as good for this type of work as new clay unless you wedge or mix (clay mixer) some fines in it(fines are from your splash pan)pour the water off and scrap them into the reclaim.Mix and age for a spell.

We make lots of oval large platters in various sizes here from thrift store plastic forms. I have-8 10 made right now in bisque or green form.

Recalim clay is whats called short (cracks and does not throw tall) as its lacking in fines often and since you are having cracking issues I would avoid it. We use relaim  for platters in the peter pugger but always add the slip from splash pan and age it a few weeks. Then use the slab roller.

Clay slab thickness is also critical-to tyhis cracks to thick it's to heavy for function.

1st coat the form with mold soap (yes you can use oil ,wd 40-laundry soap-valvoline 30 or 5w 80 ,murphys oil soap-your grandmothers hair oil, old transmisssion fiuld,grease from squirrel poop or whatever as people use all kinds of crazy stuff) wet  a dampened sponge  and dip in mold soap (from axner) I avoid oil products myself and use water based mold soap as its washes off easy as well.

I do love the 80 weight oil in my roto tiller transmission as well as my 4x4 gear box on two of my trucks. I also like wd 40 to remove stickers from surfaces as its a great cleaner, and I am fond of squirrels and leave their poop alone.

Roll oll out slab and drape into form trying not to flex the slap much as clay has memory and will not be happy bending to much. as it will remenbver this and crack more. Cut off excess clay with a tool around plastic form Let dry in slump form for a bit. running your fingernail under edge is also helpful as it drys.When its firm we have a tool that cuts a clean round edge as it tracks around plastic edge. Its a metal tool from local supply house made of metal. When clay is dry enough to support itself from form the platter is removed and edge sponged and signed and dried on ware board.

The only troube is using reclaim clay that is to short and that stuff will crack easy.

Pay special attention to slab thickness as well.

After that paltters are not babied and dry in sun or in studio heat deopending on the season

For thrown platters well that's another story.

PS these platters are all a mix of Daves porcelain and 1/2 & 1/2 both cone 10 clays from laguna-the 1/2 & 1/2 is for strength as large slabs with straigh porcelain crack and warp to much. This mix is what I came up with that works of large slump forms-1/2&1/2 is 1/2 daves porcelain and 1/2 WSO

we mix up this mix in our peter pugger for slab work

I also had ordered long ago a speacial ton of Daaves porcelain with white small grog for slab work that also works.

Your clay I assume is cone 6? and I assume is groged stoneware?Using the right clay will help you as well.

The only material I get from plainsman is Alberta slip usually use 3 bags a year so I'm not up on thier clays

I do not pass the clay thru the slab roller but once as it got two rollers that are both powered and the less I move the slabs the less they remember (clay has memory)

If you are moving them thru twice  keep them flat and roll them 1/2 turn if that makes sense not a full 180 but 90 from the orginal run

 

[ronfire]

I do use the slab roller and change orientation of the clay as it thins down to aprox 1/4". I then lay the form on the clay,fold the excess canvas over the mold and flip the whole thing over. I do not have to pick up the clay , just goes on right from the roller canvas lightly work the clay into the form and trim the edge. I then run my thumb  under the edge to make sure it does not catch on the mold.

Contacted plainsman to see if there is a better cone 6 clay to use. I have a bag of cone 10 Laguna clay that as given to me that worked well for the platters but not sure what it will do if only glaze fired to cone 6.

 

[Mark C.]

Cone 10 clay is no good at cone 6 so forget it as it will weep.See what plainsmen has

[Mark C.]

You want some tooth or grog in the larger slab clay to holod up to the stress of slab work.Cone 6 is limited for sure in this area.

[ronfire]

Well I think I solved the problem

I roll out the clay on the slab roller and let it dry out on the canvas until it is leather hard and then place it in the form and gently work it into the platter shape. So far I have gotten 5 out of 5  with the reclaimed clay that has been sitting for almost a year with lots of mold colour to it.

I think the trick is to let the slab dry mostly out before using it.

I recycle all my clay, slip and let the solids settle out of my water before discarding the water and saving the clay sludge.

[oldlady]

you are welcome.

[ronfire]

3 hours ago, oldlady said:

you are welcome.

Sorry oldlady, meant to say thanks. Was trying to send the above post as a reply to your PM but could not find it back. Now to see if they will fire ok. I place them on 1/4" clay rollers to allow movement . Seams to help with the larger pieces.

I have 6 platters to bisque next load and think I will try them on edge, had good luck with dinner plates this way.

 

[Sorcery]

On 3/27/2020 at 7:33 PM, ronfire said:

the clay on the slab roller and let it dry out on the canvas until it is leather hard and then place

They say all the drying shrink is done by leather hard.

This plus any more water will want to fall with gravity to the bottom of the form. Causing great uneveness of moisture.

Reclaim....reclaim is what we make it.

Short reclaim isn't processed correctly.

Your reclaim sounds fab!

Happy for your success!

Sorce