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cabako

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About cabako

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  1. Seeing Cones

    Ok I ordered a pair of Pyramex S3560SFJ for $10 shipped on ebay, these are the green laser type glasses that filter out IR/NIR as well as UV. I guess under those I'll wear sunglasses that can cut down the visible light enough to see the cones. My peep hole is large enough that I can view inside from a few feet away. This seems like a definite challenge for those with traditional smaller peep holes.
  2. Seeing Cones

    I have polycarbonate safety sun glasses I use for work i was planning on using. Maybe doubling up If i need to. Clear polycarbonate blocks UVA/B light 100%. I also have polarized sun glasses, pol lenses also block all UV light.
  3. Seeing Cones

    I am doing an oil firing this friday or saturday to hopefully cone 10 in reduction. I have a 3-4 inch large peep hole forced /air entrance point. I have the cones in direct line of sight but they are towards the back of the kiln...not sure how this is going to work out. I plan to use only dark sun glasses to see in...
  4. Biodiesel Fired Kiln

    HBP thanks that makes sense now. Oddly enough its now about a gallon's worth of bio or 128,000 BTU needed for 8 hrs at 16k BTU/hr. I think I was undersized on the burner nozzle, probably a 1gph nozzle run at lower psi would work. But I think firing with veg oil is probably the way to go as its ~3x more energy per gal than the biodiesel and little electricity involved. The "burner" doesn't have to be inside I suppose. It just seemed the logical way to do it with the scrap Iron i could get my hands on. Eventually I would like to fab up stepped angle iron plates as others have used. Then it just drips in, heats up and vaporizes at the inlet. I think the next hard part will be getting all the oil oxidized. I'll be away for two weeks and won't be able to fire until mid sept probably. Tyler glad you are enjoying it!
  5. Contemporary Ceramics

    It looks to me like he might be using the pen to add nucleation sites onto the pot. This is where a crystal's center will develop and spread outward. Or yes he could just be using it as a pointer LOL
  6. Biodiesel Fired Kiln

    Here is a picture of the oil inlets, burner assembly and carbon i punched out of the inlet tube, it was completely solid. Odd thing is the firing was going fine until I turned the flow off. In any case, this setup works but needs to be improved, it is a very unstable setup and very dangerous as is. Metal oil lines are required and more oxygen entering the inlet tube would prevent carbon buildup. Anyway, the glazed pieces are still intact, I may try to re work and refire tonight...maybe... PS I don't know why my pics always turn sideways, apologies...
  7. Biodiesel Fired Kiln

    Here is a video of 4th test fire trying to reach cone 10. I started off the kiln to 350C with propane for 1.5 hrs, then switched to biodiesel for about 1.5 hrs until 1000C and then I ran out (only had about a half gallon of bio) and I switched to the waste veg oil. This video is during the WVO phase. I had a orton cone 6 and cone 10 placed in hopes to get a test Glaze fire. I tested out recycled filter media which was similar in property to custer feldspar. I made various test tiles with extra silica, clay, emulsifiers added. Got some very good consistencies & "glaze" application. I turned the kiln off shortly after this video as it was too smoky and did not want to draw attention since I am in a residential area. I realize that this is not a good situation, it looked like Heavy reduction since I am only using a small fan for forced air. The air and oil is directed to a mass of metal giving surface area to burn. I waited 30 minutes until full dark to re start start only to find that my oil inlet was plugged with what marcia called "klinkers" this is probably pyrolized oil which was allowed to cool and harden. I will post a picture of the setup and carbon shortly. https://youtu.be/dyEw098aXzo?t=3s
  8. To follow up: you could also try an oxygen trap found here: http://www.sigmaaldrich.com/catalog/product/aldrich/z290238?lang=en&region=US I would use UHP grade nitrogen ( trace amounts 100ppm or less usually of hydrocarbon, oxygen, and water) and then place an oxygen trap in line to get the last traces of oxygen out of your gas.
  9. Biodiesel Fired Kiln

    Marcia, Thanks for the feedback & info. I definitely need a baffle/burner stair system as you have pictured. I am lucky enough to have access to pre filtered and cleaned waste veg oil. It goes through industrial centrifuges to remove particulates and fines and is then vacuum dried. A forced air burner like you show is probably the best way to go on a larger kiln. but I would want to use biodiesel and not WVO in a system like that. I think this model is the cheapest I have found: http://www.supplyhouse.com/Beckett-B2007-AFG-Flame-Retention-Residential-Oil-Burner?gclid=EAIaIQobChMIgKbWm7Gx1QIVzYuzCh10pAhZEAQYASABEgJuHfD_BwE Nozzle and baffle still need to be sized appropriately of course. here are pics of the oil inlet & "burner" pieces I have in the kiln. No clinkers that I can see. But I think some oil did get below the kiln shelf on the left. Floor will probably need to be replaced. This was a very quick firing just to see how hot I could get. I think a longer slower firing could build up kilnkers.
  10. Biodiesel Fired Kiln

    Well the saga continues... I've decided that instead of using a cheap noisy air compressor and burner (the air comp. I think would work properly for this application is $450), a gravity fed drip system of vegetable oil rather than biodiesel is probably the simplest and easiest system. It seems that many potters have come to this conclusion before me... In this clip the kiln is fired to 1000C using propane, then the propane is turned off and a 2 gallon can of dry, filtered WVO is fed into the kiln via a metal tube and onto a steel plate. Sorry for the smoke neighbors! Definitely will have to fire this at night. I think with a small electric fan pointing into the burner port I could achieve cone 10 temps and a cleaner burn. Please remember this is a TEST kiln ! Takeaways from this attempt was that the oil needs to be introduced at around 1000C rather than 600C i tried previously but the burn rate was not fast enough. Also more metal pieces in the flow of the oil path will give it greater surface area and chance to burn. I think un burned oil was dripping down under the fiber and bricks...Will look tomorrow. https://youtu.be/lLIlgGIyPVA
  11. have you checked the purity of your gas? You could try using lab grade ultra high purity "UHP" nitrogen or argon. Maybe if the kiln was under vacuum it would be perfectly inert....can you put a kiln that high temp under vacuum?
  12. Has anyone ever direct injected compressed air into a kiln to maintain oxidation? Is this just not a good idea due to temperature fluctuations? What about if it is slowly diffused into the kiln somehow from the bottom? What about (gulp) pure oxygen??
  13. Biodiesel Fired Kiln

    Ok good point! From a government website: Biodiesel has an air fuel ratio of 13.8:1 So then 1kg of Soybean C18 based bio needs 13.8kg of air (23% Oxygen wt.) for total combustion. 1 gallon of bio has a density of about 0.880 g/mL which is about 7.34 lbs/gal. 1 gallon of bio contains about 128,000 BTU/Gal. Lets assume the worst and use HBP's 16,000 BTU/ft^3 number to fire my 3ft^3 thin fiber kiln to cone 10. 16x3 = 48,000 BTUs or 0.375 gal of bio (this seems really low to me...) 0.375 x 7.34 = 2.75 lbs or 1.25Kg of bio... 1.25 x 13.8 = 17.25Kg of air. Density of this air coming out hot of air compressor @ 35C = 1.46 Kg/m3 = 25.185 M^3 or 889.4 Cubic Feet needed. Lets say we want to spread the firing out over 8 hrs = 889.4/480 min = 1.85 CFM total required... When sizing the nozzle it is rated in gallons per hour. In this case I need 0.375/8 = 0.047 Gph. I am at 0.25 Gph @ 5 psi thru nozzle which is using 0.49 CFM. According to this I am over on fuel and low on air. Since this is a fiber kiln it probably requires much much more BTUs... I didn't have my morning coffee today...anyone want to check my math?
  14. Biodiesel Fired Kiln

    Here is a video of 2nd firing, Nozzle can be seen clearly in this one. https://www.youtube.com/watch?v=RkkIJcSrzuE A few observations: the heating seemed to stall around 760-780C. Typically if heating stopped with my propane burner I would crack the lid slightly and the temp would shoot up again. That didn't happen in this case, temperature would only decrease. Even with an extra forced air line at the nozzle/inlet I tried increasing pressure from 5 psi to 10 psi in the hopes of getting more fuel out. I believe this only increased the air flow. Larger nozzle size, 0.65 or 1.0 gph may be needed. The air compressor I am using is very small, cheap and constantly runs. A larger tank & air production volume is necessary so it won't constantly run & overheat. This may defeat the point of using this system however. I will have to calculate the cost of air compressor usage Vs. Electric kiln... Might look into a pre-fab oil burner system...BUT I think at the end of the day the easiest solution is a gravity fed delivery, similar to the 3-tiered veg oil burner system that Sam Clarkson built. (thank you for the reference Triolaz)
  15. Good Deal On Brent Wheels

    Good find. I am in Bakersfield and need a wheel. Hes got other stuff up too. Sounds like tight pickup window and removal is a hassel. But worth it. Might have to go for a drive...
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