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jrgpots

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  1. Like
    jrgpots got a reaction from Bill Kielb in Gas kiln stalled . Why?   
    Bill, I would love your spreadsheet logs.  I don't want to hijack this thread any more than this.
     
    Jed
  2. Like
    jrgpots reacted to neilestrick in minnesota flt top hardware in need of a home   
    @jrgpots I'm going to move this to the marketplace.
     
  3. Like
    jrgpots got a reaction from Min in stupid questions about chimney   
    You are right.  It would have had a better "draw" that way/
     
    Jed
  4. Like
    jrgpots reacted to Sorcery in stupid questions about chimney   
    Should've called it a sucky question.
    Sorce
  5. Like
    jrgpots reacted to neilestrick in stupid questions about chimney   
    I usually build the chimney to the top of the arch so it direct the flame into the overhead hood better and doesn't heat up any steel on the back of the kiln. Go 9" below the damper, 4.5" above.
  6. Like
    jrgpots reacted to neilestrick in Can a kiln be rewired or converted to fire to a higher temperature?   
    Not at all! I should have explained more: Typically when backup insulation is added to electric kilns it's in the form of rigid board. It's easy to work with and harder to compress. It still can be compressed, though, so they'll use a set of narrow bands around the bricks under the board to keep them tight. But if your bricks aren't rounded at the corners those ands will cut into the brick. The other thing they do is put creases in the outer body band at the corners so they don't get compression of the backup insulation there when it's tightened up.
  7. Like
    jrgpots got a reaction from Babs in Has anyone used a furnace IFC unit to control a gas kiln?   
    what seems "fun" to some, seems overwhelming to others....
  8. Like
    jrgpots reacted to neilestrick in Has anyone used a furnace IFC unit to control a gas kiln?   
    Unless you've got auto-ignition on the kiln, a control board would be overkill, especially if you're already using a high limit shutoff controller. With a basic Baso system, you'll be manually lighting the system, and the high limit controller will open or close the solenoids as needed to shut the system down when it reaches the safety temp. That's a pretty safe system. If you're using power burners, then you also want to wire it up so the solenoids shut down the gas if there's a power loss to the blowers- basically put everything on the same circuit.
    If you're wanting the board to control the rate of climb, etc, then you need valves that can adjust the degree of gas flow, not just cycle them on and off like an electric kiln. When they cycle on and off, the pressure in the kiln gets messed up and the kiln fires very unevenly. In combination with the gas adjustments, you also need an automatic damper adjustment that can control the pressure in the kiln, as that will change as the gas and temperature increase. It becomes a pretty complex and expensive system to go fully automated.
  9. Like
    jrgpots reacted to Bill Kielb in Has anyone used a furnace IFC unit to control a gas kiln?   
    It seems you are trying for on off  (cycling) control which would be hard to manage temperature rise. Proportional control is achieved in industry using  a temperature controller which is a PID loop device. PID stands for proportional, integral and derivative which is a way of adjusting by percentage while detecting if the rate of heating is increasing. Anyway all this tech stuff, these controllers today are dirt cheap, like 20-30 bucks so probably much cheaper than  a furnace control and much more suitable to operate in the temperature range of a kiln.
    The PID control works great but for gas you really  need a valve that you adjust proportionally, say from 2% open all the way to 100%. So in addition to the baso valves which provide pilot safety you in theory need one of these controllers to proportionally adjust how much gas. In addition, for safety, redundant gas valves are usually used and a manual reset high limit is inserted. 
    Thinking about this, if on/off control is used then some form of auto pilot Or pilot restart and maybe prepurge  is needed as well. The kiln could be restarted without pilot after about 1600 degrees but I believe the old Geil left the pilot bar on through the end of firing for safety  and had a toggle for soak at one particular temp or it could be toggled to limit. In soak it would cycle on at off at setpoint within a predefined differential and limit would drop everything out and require a full manual restart.
    while this could be done, it’s probably too difficult to address all the safety requirements unless you are very familiar with the control equipment sequence of operation, fail safe designs and general safety for natural gas. My short answer is this is likely not doable for most.
  10. Like
    jrgpots reacted to Mark C. in Has anyone used a furnace IFC unit to control a gas kiln?   
    Gas kiln are pretty easy to turn up. I only turn my large kiln on (one burner) then 3 more and then up twice. Not to much time spent at it.
  11. Like
    jrgpots got a reaction from Min in Slipcasting Marbling Effects Help   
    My daughter does poured acrylics by slowly pouring the different paint colors in a cup, then without mixing them, pours them on the canvis.  There are lots of youtube videos of the technique.   What if you adapt this to you slip pouring?   Here is my idea.
    1. Find the total volume needed  for your pour.
    2.  Usee 1/3 that volume as  color #1,  1/3  as color #2, and 1/3 color #3.
    3. Carefully, add the 3 color slips into a large  container, then pour this into the mold.
    4.  Wait until you get the desired thickness and then pour the slip into a second mold. 
    5. Don't swirl the slip inside the mold.  Just tap it to remove the bubbles.
    Each time you pour, the colors will get more mixed or muttled.  There would be a limit to how many times this could be done until the slip colors would be too mixed.   At that point, you would have a new slip color. 
     
    Jed
  12. Like
    jrgpots reacted to neilestrick in Tell me about preheating primary intake   
    If everything else is done correctly, this is unnecessary. It should not be needed to make it work, but rather improve efficiency of an already functional system.  If you don't know whether or not the basic system works, it's going to be much more complicated to diagnose problems since you'll have more varaibles.
    If go forward with it, you'll need power burners because they will pull the  preheated air through the burner. I just don't see how you could do it with a venturi setup. Personally, I prefer power burners because you can use fewer burners, they're easy to adjust, and you don't have to rely on the chimney nearly so much. Plus they're easy to build.
     

  13. Like
    jrgpots reacted to Mark C. in Tell me about preheating primary intake   
    I would scrap that idea and stick to basics-let the burners heat whatever air you have-not worth the effort I think.In the grand scheme a 100 dregrees in a high fire or midfire kiln is meaningless.
    I think you are overthinking it.Just try the burners and see what happens.
    Jed I looked up the article from Nils Lou on the flat top (in studio potter Vol.6 no 1-1977)(yes I wasa subscriber then as I still am) the burners are from him I bet they are FL-1 liquid propane (Lou is dead now) burners-no blowers. I recall these as high output propane burners . I do not think they will work near as well on natural gas. as it less BTUs. Your kiln is so much smaller than a regular Minnesota flat top they could work-just get as much pressure as you can to them and it may take a few tries with orfice sizing.I would try them a few times with orfice changes before scrapping that idea.
  14. Like
    jrgpots got a reaction from Min in Boiling water causes sandy feeling outside   
    Also the mugs really get hot when placed in the microwave if they are weeping.
     
    Jed
  15. Like
    jrgpots reacted to liambesaw in Upgrading to a wall mount controller   
    Mine is outdoors but never exposed to any moisture outside of humidity.
    You can buy a new control panel, they're relatively cheap considering.
  16. Like
    jrgpots reacted to Bill Kielb in help with drill size for burners   
    Flakes for sure, dirt leg is important. 2009 IRC got rid of galvanized and natural  gas  zinc issue (I believe, unless it’s back) . Still many local codes don’t allow it. Clean assembly, dirt leg, no moisture very important, don’t mix black and galvanized, even more issues.
    2009 IRC G2414.4.2 (403.4.2) Steel. Steel and wrought-iron pipe shall
    be at least of standard weight (Schedule 40) and shall comply
    with one of the following:
    ASME B 36.10, 10M; ASTM A 53/A 53M; or ASTM A 106.
    Commentary: Steel pipe must be Schedule 40 or heavier, must comply
    with one of the listed standards and can be black
    iron or galvanized. Contrary to popular belief, natural
    gas does not adversely react with the zinc coating on
    galvanized pipe."
  17. Like
    jrgpots got a reaction from Pres in Wild clay dries soooo slow   
    bentonite clays also dry slowly
  18. Like
    jrgpots got a reaction from Hulk in help with drill size for burners   
    These two burner fired a 60 cubic foot minnesota flat top using propane.  I fired them up with propane and they worked great.  Then the copper tubing got flattened . So I am  repairing them.   I have never fired them up using natural gas.  I will drill them out for natural gas and find the best pressure they run at.   To run the test, I will need to get a low
    pressure regulator
    Jed
  19. Like
    jrgpots got a reaction from Hulk in Wild clay dries soooo slow   
    bentonite clays also dry slowly
  20. Like
    jrgpots reacted to Bill Kielb in help with drill size for burners   
    I don’t get it, natural gas power burners usually run inches of pressure, not PSI. A 3/16 drill gets you 126000 btu each. What am I missing? Power or Venturi, you will need A 3/16 orifice.??????
  21. Like
    jrgpots got a reaction from Babs in Batt wash   
    With this Covid thing, I have given up  using bat wash.  I figure if the bats want to stay clean, they can shower off in the rain.  Besides, it was nearly impossible to teach them social distancing.  They would not keep their masks on when they were out of their cave.  lol...
    Jed
  22. Like
    jrgpots reacted to Marcia Selsor in Oxblood Glaze, How To Have A Green Where The Glazed Is Not Reduced   
    I haven't fired ^6 reduction for a while.My friend finished his kiln a few blocks from my home and asked me to help fire it. Here are some of my Selsor Copper Red results. these are from 2 firings in the last month. The darker reds are 1/2 cone hotter.
     

  23. Like
    jrgpots got a reaction from Bill Kielb in Batt wash   
    With this Covid thing, I have given up  using bat wash.  I figure if the bats want to stay clean, they can shower off in the rain.  Besides, it was nearly impossible to teach them social distancing.  They would not keep their masks on when they were out of their cave.  lol...
    Jed
  24. Like
    jrgpots got a reaction from Bill Kielb in what size regulator do I buy?   
    2# at the meter,  30 ft  of 1" IPS. Based on above chart max output from the line would be 4424 cfh.  There is nominal use in the house.  A pool heater at 400,000 Btu is on the meter as well.  I think if I run the pool and kiln at the same time, I'd run into problems using the current meter.  So I will turn off the pool heater when I fire up the kiln.
    Jed
  25. Like
    jrgpots reacted to Min in Hump molds   
    Nope, not that stuff but the higher density extruded rigid insulation boards from a building supply place. It can be sanded down after roughing out and it comes out pretty smooth.
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