DanaH Posted August 15, 2012 Report Share Posted August 15, 2012 Hello everyone! I am new to the forum but I have a question that I can not find the answer to. I make tiles and I just tried to make a press mold of some of the tiles that I recently made. The molds turned out beautifully. I pulled clay straight from the bag (Laguna's B-mix), pushed it into the mold and pounded the heck out of it. I then cleaned up the back and waited for it to pop out. The tiles turned out great until I fired them. I had a mix of tiles that I put through the molds and some that were only hand carved...the tiles that I popped out of my molds cracked. Every single one of them. Huge cracks! The other hand carved tiles came out just fine. So, I'm curious...what happened? I was wondering if it was a compression problem, but it is clay straight from the bag. Maybe plaster getting into the clay? If that is the case how do you use your molds without getting plaster into them. I have done searches online to see that everyone else's molds seem to be working, but not a lot of information on what could be happening to my tiles. If anyone has any ideas, I would love to hear them! Thank you! Thank you! Link to comment Share on other sites More sharing options...
Mark C. Posted August 15, 2012 Report Share Posted August 15, 2012 Hello everyone! I am new to the forum but I have a question that I can not find the answer to. I make tiles and I just tried to make a press mold of some of the tiles that I recently made. The molds turned out beautifully. I pulled clay straight from the bag (Laguna's B-mix), pushed it into the mold and pounded the heck out of it. I then cleaned up the back and waited for it to pop out. The tiles turned out great until I fired them. I had a mix of tiles that I put through the molds and some that were only hand carved...the tiles that I popped out of my molds cracked. Every single one of them. Huge cracks! The other hand carved tiles came out just fine. So, I'm curious...what happened? I was wondering if it was a compression problem, but it is clay straight from the bag. Maybe plaster getting into the clay? If that is the case how do you use your molds without getting plaster into them. I have done searches online to see that everyone else's molds seem to be working, but not a lot of information on what could be happening to my tiles. If anyone has any ideas, I would love to hear them! Thank you! Thank you! I would like so more info to answer well What size are these tiles 12x12 inches?? 4x4s?? 18x18? that would help me with an answer How thick are they?? 1/4 inch 3/8th??3/4 inch??? Mark Link to comment Share on other sites More sharing options...
neilestrick Posted August 15, 2012 Report Share Posted August 15, 2012 I would like so more info to answer well What size are these tiles 12x12 inches?? 4x4s?? 18x18? that would help me with an answer How thick are they?? 1/4 inch 3/8th??3/4 inch??? Mark That plus how did you stack them in the kiln? Firing schedule? Give us everything! Link to comment Share on other sites More sharing options...
DanaH Posted August 16, 2012 Author Report Share Posted August 16, 2012 ok, my tiles are 6x6 and I would say about 1/4" thick. I bisque fire to 05 and then fired to cone 5. I fire them flat on hi-fire tile setters to keep them from warping during the firing process. All of my other tiles fired fine, they are the same clay being fired at the same time as the "molded" tiles. Two of the molded tiles had hairline cracks during the bisque and I thought the others were ok, but maybe not. Upon glaze firing, they all cracked, some of them in half(the molded tiles). Does that help? I hope so! Thanks! Dana Hello everyone! I am new to the forum but I have a question that I can not find the answer to. I make tiles and I just tried to make a press mold of some of the tiles that I recently made. The molds turned out beautifully. I pulled clay straight from the bag (Laguna's B-mix), pushed it into the mold and pounded the heck out of it. I then cleaned up the back and waited for it to pop out. The tiles turned out great until I fired them. I had a mix of tiles that I put through the molds and some that were only hand carved...the tiles that I popped out of my molds cracked. Every single one of them. Huge cracks! The other hand carved tiles came out just fine. So, I'm curious...what happened? I was wondering if it was a compression problem, but it is clay straight from the bag. Maybe plaster getting into the clay? If that is the case how do you use your molds without getting plaster into them. I have done searches online to see that everyone else's molds seem to be working, but not a lot of information on what could be happening to my tiles. If anyone has any ideas, I would love to hear them! Thank you! Thank you! Link to comment Share on other sites More sharing options...
clay lover Posted August 17, 2012 Report Share Posted August 17, 2012 I have had this sort of cracking along the lines of the orriginal chunks of clay that were pressed into the mold, but only doing small, 3x3 sprig molds. even when mashing mightily with my thumbs as each chunk was added, still having internal seperations in the not damp enough clay. "Straight out of the bag" at my place could be also too dry to throw, so that is no guarantee. Try using really sort squishy clay and see what happens. How are the handcarved ones done differently, dampness wise? Does the mold suck moisture out of the clay really fast? and the carved block is cut from the bag of clay in 1 hunk? Link to comment Share on other sites More sharing options...
DanaH Posted August 17, 2012 Author Report Share Posted August 17, 2012 For the molded tiles, it was a fresh bag that I had just purchased and seemed pretty moist. I then cut a slab from the clay that was a little thicker than the finished tile. I then mushed it in, to make sure all of the raised areas had clay. It took about 10 minutes for the tile to release out of the mold. I don't know if that was quick or slow (this is my first time making and using molds). My hand carved tiles are using the same clay that I roll out to the same thickness. 1/4". I wait until they are leather hard to carve and then place them on a piece of dry wall to dry. All of the tiles are 6x6. Thanks! I appreciate the responses! Dana I have had this sort of cracking along the lines of the orriginal chunks of clay that were pressed into the mold, but only doing small, 3x3 sprig molds. even when mashing mightily with my thumbs as each chunk was added, still having internal seperations in the not damp enough clay. "Straight out of the bag" at my place could be also too dry to throw, so that is no guarantee. Try using really sort squishy clay and see what happens. How are the handcarved ones done differently, dampness wise? Does the mold suck moisture out of the clay really fast? and the carved block is cut from the bag of clay in 1 hunk? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.