kayleyvdb Posted November 6, 2020 Report Share Posted November 6, 2020 Hi all! I recently mixed up a batch of plainsman G2934 with 5% zircopax and 20% G2926B for a satin white glaze. I measured the specific gravity and then flocculated the glaze. The test tile looked perfect, but the pieces I glazed don’t. here’s the inner rim of a bottle - the areas where the glaze was the thickest pulled away and now the inner rims are raw and the glaze is dripped. Any idea on why this happened? I’m going to guess the glaze was too thick or too flocculated... though I was really careful with my measurements. Now I’m left wondering if there’s anything I can do to try to smooth out these drips. It’s okay if there’s a little exposed raw clay but the globs of glaze gotta go. Would a second firing help? Any tips appreciated! Link to comment Share on other sites More sharing options...
Chilly Posted November 6, 2020 Report Share Posted November 6, 2020 My experience with this is it's not worth the effort to fix this vase. Test tiles will behave different to test vases. Make another sample vase or ten. Use them as tests. Dip vase #1 for 1 second, vase #2 for 2 seconds, vase #3 for 3 seconds. Add 10 drops more water. Dip vase #4 for 1 second, vase #5 for 2 seconds, vase #6 for 3 seconds. Add 10 drops more water. Repeat. Change numbers above to suit batch size of glaze and size of test vase. Link to comment Share on other sites More sharing options...
kayleyvdb Posted November 6, 2020 Author Report Share Posted November 6, 2020 @Chilly This is the advice is was afraid to get. It’s an entire kiln of wholesale items. :( Thanks for the tip! I’ll definitely do more tests next time I try a new glaze. Link to comment Share on other sites More sharing options...
Min Posted November 6, 2020 Report Share Posted November 6, 2020 It would be a royal pain to do but if you had the time and patience you could use a dremel with a diamond bit and try grinding the drips down. You need to have water dribbling on the area as you are grinding so you don't wear out the diamond bit. After grinding I would refire to cone 5 1/2 to (hopefully) smooth out the ground areas. It is very slow going so probably not worth the effort. How porous the bisque is plus how long you dip/pour the glaze is going to make a difference in thickness. If you see any cracks in the raw glaze as it dries on the pots then chances are it will crawl during the firing. If you poured the inside of the pots then dipped the outside the double thickness on the rim could have been the cause of the thick glaze layer. If this is how you glazed them then going forward I'ld wax the liner glaze down about an inch before dipping the outside. Link to comment Share on other sites More sharing options...
kayleyvdb Posted November 6, 2020 Author Report Share Posted November 6, 2020 @Min grinding the glaze down might actually be worth it, to be honest. The shape of this piece isn’t easy for me to throw consistently and it’s a big batch. Thanks for the tip! I already have a dremel... heading out to buy diamond bits now! Link to comment Share on other sites More sharing options...
Hulk Posted November 7, 2020 Report Share Posted November 7, 2020 After grinding, polishing may suffice; perhaps start with 220 grit, then 400 - where each step removes the scratches from the courser grit; for a polished look, try 1000. Link to comment Share on other sites More sharing options...
Chilly Posted November 9, 2020 Report Share Posted November 9, 2020 On 11/6/2020 at 5:44 PM, kayleyvdb said: grinding the glaze down might actually be worth it On 11/6/2020 at 4:43 PM, Min said: water dribbling on the area as you are grinding Make sure it's thoroughly dried out before re-firing. Link to comment Share on other sites More sharing options...
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