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David Woodin

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David Woodin last won the day on January 31 2015

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About David Woodin

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    Reno NV

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  1. I know it is a bad time to think about your problem, but you are mixing different base glazes together when you double dip. You could probably get the same effect using the same base but changing the colorants. there may be times that you have a Custer base and than a G200 or Nephline Sye base on top of it, for me this would invite trouble. There is no reason why you are stuck with different bases to get what you want. It will require some color testing but both glazes would be compatable. David
  2. The glaze Al/Si is not in food safe range. Food safe limits developed by John Hesselberth doesn't use Lithium. The glaze as written doesn't add up to 100 %, Dolomite should be 5.6. John Britt on page 111 says do not use on functional surfaces. (Mid range Glazes) David
  3. Your glaze firing program doesn't agree with the Barlett slow glaze program, the temperature of 2167 F even with a 20 min hold woudln't be cone 6 , some where around cone 5 and cone 5.5. You are getting cone 6 past 90 degree so your kiln must be going very slow. How many hours is the firing? Two of the glazes on the next page are within cone 6 food safe limits. Bright sky blue and Rasberry. So probably your clay is suspect. David
  4. You could take out the Zinc, it will still have the same AL/SI ratio, but it will be a different glaze and probably fire in the cone 7 range, it may be possible to use a frit to get more fluxing. The new glaze brought up to 100% would be neph sy 56.5, whiting 20.6, EPK 16.9, silica 6.0 David
  5. The test I showed would keep the same AL/SI ratio and should keep the same matte surface. The only way to tell if it would is to fire the 7 tests at cone 6. David
  6. The glaze you now have is not a cone 6 glaze and you fire to cone 6, to make it a cone 6 glaze you need more silica in the glaze. You could try a line blend to get the silica into the cone 6 range and keep the AL/Si ratio the same as you now have. The easy way to do a line blend is to mix A and B containers first (about 350 grams batch each NEPH 180.6 145.6 Whiting 65.8 53.2 Zinc 30.1 24.5 EPK 53.9 89.6 Silica` 19.6 37.5 If You have a 60 cc syringe you squirt the glaze into 7 small cups as follows: 1 2 3 4 5 6 7 cups each cup has this recipe in it A 96 80 64 48 32 16 0 Nep Sy whiting Zinc EPK Silica B 0 16 32 48 64 80 96 1 51.6 18.8 8.6 15.4 5.6 2 49.9 18.2 8.3 17.1 6.5 3 48.3 17.6 8.1 18.8 7.3 4 46.6 17.9 7.8 20.5 8.2 5 44.9 16.4 7.5 22.2 9 6 43.3 15,8 7.3 23.9 9.9 7 41.6 15.2 7 25.6 10.7 You also could just make the above separated batches. they will start getting into cone 6 range at 3 on. The 20 grid biaxial is a simplified curry blend, but it will have matte to shiney glazes at cone 6. The above line blend will be in the matte range you now like. Sorry for the confusion. David
  7. Unfortunately your glazes Silica is not in the cone 6 range. If you want to make some tests you can get it within the cone 6 range and probably get some more good glazes also. I would suggest a 20 grid biaxial test. If you are not sure how to make this test I could help you off line. My email is hdwoodin@gmail.com David
  8. For your slow bisque program, try changing the 100 F ramp to 1100 F, to 100 F ramp to 1200 F, this helps to burn out impurities, also follow the rest of the slow bisque program. David
  9. Your glaze is not quite in the food safe range, and whiting can cause outgassing. If you want to bring the glaze into the food safe range and use wollastonite in place of whiting than a better way to bring it into the food safe range is making a line blend, keeping the same Al/Si ratio. A 7 tile blend : A B Frit 3134 92.5 134.48 Custer 78.3 113.6 EPK 60.5 31.4 TALC 17.8 25.8 wollastonite 16.5 24.06 silica 84.4 20.65 Millilitres per sample need 60 cc syringe pet store should have them No 1 2 3 4 5 6 7 A 96 80 64 48 32 16 0 B 0 16 32 48 64 80 96 David
  10. L&l Vs Skutt

    The Skutt has tuned elements which help to make them fire evenly. This means the top and bottom elements fire hotter than the middle elements, also each row of bricks has two elements in it which give it plenty of capacity to reach temperature. David
  11. Lockerbie K Kick Wheel

    www.LagunaClay.com have parts including a motor kit for the Model K. It is a great wheel and lasts for years.
  12. Advice On Firing My L&l E23T To Cone 10?

    If you are still going to use cone 10 clay you will have to find out how low it can go wihout leaking, You may have to switch to cone 6. David
  13. How To Fire Cress 25P

    I think the thumb wheel is for the speed of the firing with 1 being the slowest. If there is no kiln sitter the kiln will not shut off by itself. You have to put cones in the kiln and watch the cones and shut it off manually. David
  14. Glaze Chemistry Class

    Take a look at www.matrix2000.co.nz a very good glaze course on line with help from the instructor for every lesson. David
  15. Kiln Quandary

    While the kiln is unplugged start checking beyond the power relay for shorts to ground or between the wires going to the element power terminal. You should be reading around 17 ohms at that terminal for the wires that go to the elements. You should not read anything to ground with your ohmmeter on a high setting on either wire to ground. David