Preventing warping?

Hi, I guess this would depend on how big a piece is, but I just turn the flat piece out on a ware board ( it's absorbant, partical board) then lay another ware board on top of it. Sometimes, I leave the piece on the canvas when I do this. Then I flip it over once in a while. It takes longer to dry but usually it doesn't warp. I hope this helps. Sandi

Yep, thats the way i do it as well just so both sides dry evenly.. Hugs Eddie

----- Original Message ----- From: "Bubbles_" Newsgroups: rec.crafts.pottery Sent: Monday, June 05, 2006 2:11 PM Subject: Preventing warping?

[Try drying them on a scrap piece of gypsum wallboard (like Sheetrock). If there's no raised detail, you can stack them with wallboard pieces interleaved, but if there is, just lay them out flat and turn them over after a day or so. I've had good luck with the green kind, used for bathrooms. I think the paper's less likely to deteriorate with a little moisture, otherwise there's not much difference.]

Andrew Werby

Great tip for those in countries that us gyprock (like Canada, where I once lived), but over here, they just gypsum direct on the walls, for pete's sake! GRRR!!! Makes hanging pictures a university course subject! AGH!!! /end rant

I don't think I have seen anything even resembling gyprock here in Switzerland - or else that would be a really fab tip. Thanks!

Marianne - always keeping an eye out for smart stuff to use!

Hi Sandi and huggable Eddie!

I do do that most of the time, and it really does help, but sometimes the piece is only flat on one side. What do you do then?

Also - pieces that haven't warped during drying sometimes still warp under firing - even under glaze firing (which is the sure bummer! hehe!)

In bisque, you can allways put something flat on top of the piece, but during glaze firing, that is seldom an option. Thereof also my question if firing higher without glaze, and then firing a little lower with glaze on the piece, might help avoid warping during high firing (1250 C)

Marianne

Slow drying, covered with something flat so that the corners do not turn up. Then for bisque and glaze fire on a bed of grog. Seems to help, the grog allows for movement as it shrinks and I think helps. Its about all I can offer though, good luck.

Thanks AnneMarie. I don't have grog, but I do have sand. I suppose it must be that it facilitates shrinkage better. Will make a note of it in my firing book!

Marianne (ie. your alter ego ;-)

Are you sure about that? I swear I just saw a truck load of the stuff recently on the drive through that area. Maybe it was farther south... I even saw a place that looked way too much like Home Depot (but named something else).

Anyway...

You want something stiff (won't bend since clay has a memory) but that is light enough that you can sandwich the tiles between the 'boards' to flip them over so each side gets dry in equal measure.

This thread was just posted on Clayart and what I read that most stood out for me was waxing the edges (sides not top or bottom) of the tiles since that is where things dry out too quickly relative to the rest of the tile. Good luck!

You have to work with the clay.

• Water flow down hill

• Clay shrinks as it dries

Try fliping them over occassionally and (time permitting) slooooooooower drying periods.

Try using thin foam around the raised areas but still use the sheetrock both on top and on the bottom. Sometimes a built up form will cause warpage no matter what you do. Because the extra clay in the built up piece dries at a much slower rate. Try taking some of the excess clay from the back (flat) part, sort of hollow out any large areas. Sandeann

Bubbles_ wrote:

Ahh - so you get it from M-Park or Coop Bau und Hobby?

I have had a bit better luck sandwiching the tiles between two wooden bats and flipping as you have suggested :-)

I'm not really wanting to use wax, as in my teeny workshop, I don't want to muck around with melting it and so forth. Though maybe I can just put strips of plastic around the edges and stroke them on to seal.

I think my new drying shelves are helping lots as well. Hubby made them and they are just a frame with the shelf itselv made of stretch-wire - kind of like the see-through walking surface some smaller bridges have - so that the ware also dries from underneath. Before I set ware on the drying shelves, though, I let it dry on a bat covered with plastic which I air out a bit when I am in my workshop - and sometimes I turn it upside down (on a bit of foam rubber, if the edges are uneven) on the bat as well. When it is properly leather hard, I set it on the drying shelf.

Thanks! :-)

Marianne

Thanks!

Marianne