Jump to content

kraythe

Members
  • Content count

    33
  • Joined

  • Last visited

About kraythe

  • Rank
    Member

Recent Profile Visitors

578 profile views
  1. Glaze Application Questions.

    Another question, if I am using a glaze with cobalt inside a bowl and want to seal it with a non toxic glaze can I apply the clear over the cobalt and fire once and be sure the clear will not mix with the cobalt layer?
  2. Stopping Glaze Drip Beads? This is probably more of an application question than a chemistry question but I am getting a problem where I have glazes with Specific Gravity around 1.45 that are forming beads of glaze on the rim of cups and other wares when dipping or pouring the glaze I am wondering if there is something I can add to the glaze to stop that. Id hate to thin the glaze further and I don't have the equipment to spray safely. So I am wondering if anyone can help me out with tips on chemistry, specific gravity or application technique. For dipping I will wax the foot then dip up to the foot for 6 seconds or so then lift the piece out. For pouring I am filling the inside of the piece with glaze then pouring while rotating the rim. Removing Tong / Finger Marks? When dipping my pots in the glaze I often get marks for where the tongs or fingers were holding the piece and I would like to fill them in a way to not be obvious that they were there. I have tried a small squeeze bottle to drip the glaze but that invariably results in a small bump that doesn't go away in the firing. Any suggestions of how I can do this without making the marks on the piece? Seal over toxic materials with clear? Another question, if I am using a glaze with cobalt inside a bowl and want to seal it with a non toxic glaze can I apply the clear over the cobalt and fire once and be sure the clear will not mix with the cobalt layer?
  3. Apologies for the thread spam but I have another question for you experts. I currently have glaze recipes that call for silica 200 mesh but I only have 350 mesh and I was wondering if that is a valid substitute or if I will be messing the glaze up. So what effect will the smaller mesh size have and does it really matter?
  4. I am sick of my current clay because the supplier wont tell me jack about it and I cant get it to fit any glaze without crazing so I was browsing through the Laguna site looking for an alternative and then I looked at some of their cone 10 clays and some have COE down to 4.6. How on earth can you glaze to that clay. Every glaze recipe I know STARTS at 6.0 and goes up from there and the most common is in the 7's. Clearly I am missing something. Can someone help me out here ?
  5. Best Cone 6 Porcelain?

    I wish I knew. They wont tell me crap about this clay, not whats in it, nothing. They just say its COE is 6.0 to which I call Bullsh...op. They wont event tell me what the recipie they have for it to not craze has in it so I cant use that as a base glaze. Basically I am sick of this clay and interested to moving to something else. I am used to working with midfire porcelain but not opposed to going to stoneware if I can find one with a nice texture or even high fire porcelain.
  6. Best Cone 6 Porcelain?

    I am using a cone 5-6 porcelain from my local supplier and I have had crap luck getting anything to fit without crazing from 5.9 COE glaze though 7.1. It's all a matter of degree how bad. My wife said the pots were crackling long after being unloaded even though I waited until I the kiln parts could be unloaded by hand to unload. I am using an olympic 1827g gas kiln.
  7. It very well could be too thin. I perhaps even slightly overfired. Had a really hard time seeing the cone through my tiny peepholes so I only went by my pyrometer. Perhaps I should have let it sit at that temp for longer. When I opened up the cone 6 was curled all the way over to floor. Even the thinnest application with a few second dip crazed. The glaze that came out rough was an FeO2 based tea duct glaze and even where it was double appied, had to pour because I made Amal batches, it was still rough texture and not glassy smooth.
  8. I finished my test run from my kiln and literally every clear glaze came out crazed, despite having some supposedly anti-craze glazes. I don't know what to use for this clay body I am using and I have about had it up to the neck with trying to find something to fit it. So I am looking for recommendations on good clay bodies for cone 6 porcelain that will actually fit some glazes. I am even open to going to cone 10 porcelain. I have limited time to do pottery and want something that I can actually fire to be functional pieces. I am open to suggestions. Thanks.
  9. I have been trying my hand at glazing for the first time as a hobbyist and I fired perhaps 20 pieces. Some of the glaze crawled like mad, other glaze crazed but my tea dust and a third clear did something unexpected. The glaze looks good and not crazed but it still feels rough to the touch I am wondering why that may be. Not enough glaze one the piece? Should I have done more than one layer to solve that? Thanks for the help.
  10. I am looking for a pyrometer for my olympic torchbearer kiln that has a connector to computer so that I can directly monitor temperature and track it in the computer. Any suggestions of something that wont break the bank?
  11. Again, to be clear I have not necessarily WANTED to make a clay body, I just want something that I can glaze to reliably. I have used premixes with lousy results and a couple of self mixes though who knows if I got those right, I am just learning the chemistry here. What I find annoying is when a supplier wont tell me basic information about a clay body and when I ask they shrug and say "just experiment" which is, in my opinion, annoying.
  12. Greetings, I already know the basics of SG if I have a measure amount of glaze and the amount of water. But what if all I have are dry ingredients? Lets say I have a dry glaze that I have planned out. I want to make perhaps 200g of it to make a small batch for testing, is there any way I can know exactly how much water to use in order to get a specific gravity of 1.45 for pouring (since I wont have enough to dip) on test pieces. As my understanding goes the SG is the weight of the water + the weight of the mass of ingredients. So my thought is that if I am going to have 200g of ingredients and then I would need 80 g by weight of water to hit the target SG. Is that the case? If not how can I hit the right SG from dry measure to wet. thanks in advance.
  13. I don't disagree, I wish this one would work better. But It doesn't. Reality intrudes. And if I ship it online the shipping will be as much as the clay. Unless you know a maker of a nice Grolleg based cone 6 porcelain with 6.5 to 7 expansion who doesn't kill for shipping. If so, please do tell and I will try them.
  14. The same problem will be there, If I don't know hats in it, don't know the expansion, it will be a pain. BUt maybe other clays will be more cooperative, I am amenable but driging to San Antonio for clay is a bit much. I don't make my living through clay. Its ah hobby is all.
×