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About tomhumf

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    Sheffield, UK

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  1. tomhumf

    Kiln bricks as props

    Ok thanks, I actually have a load of bits of shelf I kept when I cut my round shelves after kiln conversion. I will use those until I get some proper ½ " props.
  2. I need some short props for my next bisque firing. I was thinking of cutting some squares of soft kiln bricks as a temporary measure. There won't be much load on my little shelves. Will this cause any problems do you think? I know it's not a long term option with the fragile, dusty nature of them.
  3. tomhumf

    Why is glaze blue

    Thanks all, yes I've used titanium dioxide as an opacifier with other base glazes in electric kilns and it has just given a pure white. I will experiment with zirc and tin.
  4. tomhumf

    Reclaimed clay

    I was always under the impression it's best to thoroughly dry all the clay to be recycled. So it then all hydrates at the same time when you reclaim. Do some of you use all types of dryness and just mix to slurry to reclaim? I don't have a pugmill.
  5. tomhumf

    Why is glaze blue

    Hmm, maybe I'll try it on different shelves from any blues then. Would it be able to drift all through the kiln though, or just to those close by?
  6. tomhumf

    Why is glaze blue

    Materials Amt BPS Soda Feldspar 33.00 Quartz 26.00 BPS Calcium Borate Frit 14.00 China Clay 14.00 Talc 9.00 Bone Ash 4.00 Total:100.00 (g) + 7% titanium dioxide Hi, This recipe was meant to be a pure white! I did a test tile with very similar glaze which looked white. I'm wondering why it has gone so blue. It was fired in gas kiln in a fairly neutral atmosphere as far as I know. It was sat next to some cobalt glazed pots, is it possible it took the colour from them? Otherwise maybe it's the iron in the clay which is causing this? And then how to get a purer white, seems like 7% titanium is fairly high already and I wanted to see some of the body break through... just not the blue colour.
  7. tomhumf

    How did you learn to fire your own kiln?

    Hand torch is a great idea, I think I shall get one. I don't have a bag wall, my kiln is tiny and shouldn't really be trying to fire large plates... But I really want to. It fires pretty good apart from when stuff explodes.
  8. tomhumf

    How did you learn to fire your own kiln?

    I've recently converted an electric kiln to gas. Today I started firing it with cone packs I made the previous night. I had put holes holes in them, and they seemed pretty dry. Lucking after about an hour I looked in my burner port and saw debris in the bottom of kiln. Both my cone packs had exploded. I had to shut it off, wait until it cooled and brush off clay fragments from all my ware, and repack the whole thing. I've now made a load of cone packs that will be dry well before I need them. Last firing I had a load of dinner plates to bisque. I has struggled to get a low enough flame when candling the kiln. And after about 1 minute the rim of one of the plates near the flame path exploded. I pulled the flame back and continued thinking the rest were ok. I will be more careful, and keep large plates away from flames in future. I had stacked 6 plates in pairs on shelves with sand between them, to save on kiln space. Two plates were on shelves of their own because I was worried this might end badly. I do stack bowls with sand without problems. When I unloaded the kiln, all the stacked plates were cracked to bits, the plates on their own shelves were fine. So I won't stack plates like that again, I need to buy some more props and shelves. This probably doesn't help you at all, but is a reminder to me not to do stupid stuff again. Whatever you do, there will be mistakes. You've just got to learn from them.
  9. tomhumf

    Propane connectors for 2 bottles

    Thanks for that, I still haven't got round to buying one yet. They are out of stock on UK Amazon. I take it there is a one way valve on the tanks or something so the gas from a fuller one doesn't go into the emtier one?
  10. Hmm, maybe I'd be best to stamp leather hard, with just the impression then. Thanks guys, you're awesome!
  11. You mean bleed into glaze? I'm just thinking of stamping the bottom which will be unglazed, not sure I made that clear.
  12. I'm thinking of getting a rubber stamp made with my company name. Mainly for stamping boxes and stuff. Then I thought maybe I could use it for the bottom of mugs etc. Has anyone had experience of stamping bisque with rubber stamps? I would just want black lettering, so would just mix some black iron oxide with some water, and soak a sponge in it to dip stamp in? Thanks
  13. I decided to get a second gas bottle as my first was nearly empty, and I didn't want to get caught short mid firing. I'm using a single regulator to attach to my burner. I was up to about 1500F and the burner started loosing pressure. I actually lost a couple hundred degrees because I was away from kiln. I switched bottles and continued fine. Next firing I was able to use the first bottle to start off, on a low flame it worked ok. I'm pretty sure it's nearly empty now. Question is, can I connect them together somehow so I can use all the gas up in a tank, without it loosing pressure? I've seen some duel regulator things but they seem to just switch between tanks which wouldn't seem to avoid this pressure loss problem...
  14. tomhumf

    Help with raw glaze bubbles

    Thanks all. I can see firing higher could help, but already burning through more propane than I'd like so hopefully I can fix this with the glaze. The bubbles in question are all sealed over. There are a few tiny pinholes in other areas but I'm not too concerned about those, I'm not expecting a perfect finish with this body. I would have thought increasing the fluxes and reducing quartz a little would create a more fluid glaze that would get rid of the bubbles. Problem is the CaO and B2O2 levels are already over the suggested limits according to insight live. https://digitalfire.com/4sight/education/limit_formulas_and_target_formulas_206.html Perhaps this is contributing to the problem. I'm thinking maybe another flux like talc or frit3110, may be needed...mainly because I have those in stock.
  15. tomhumf

    Help with raw glaze bubbles

    Bubbles are worst on the inside. I've just read it could be to do with firing schedule. Maybe I need to hold at lower temps before glaze is melting while gases are escaping from body.

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