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Need help balancing burner / furnace

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  • wheezer
    Hello Group, After years of collecting parts, rebuilding the furnace x3 and testing various burner designs, I have FINALLY started to melt some aluminum. I
    Message 1 of 12 , Nov 6, 2010
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      Hello Group,

      After years of collecting parts, rebuilding the furnace x3
      and testing various burner designs, I have FINALLY
      started to melt some aluminum.

      I built a forge to make the lifting and pouring tongs
      as well as other tools.

      So now that I have some fire under my belt,
      I have a few questions.

      A- My furnace burner flame Temp is >>2000F, but it
      takes >> 20 minutes to get the first melt from cold.
      I am using a modified side arm burner w/ propane,
      venturi aspirated. I have a low pressure propane
      regulator set for about 10 psi. Often, the flame will
      sputter unless I close down the air inlet.
      Then the flame gets cooler.

      I am using an A20 clay-graphite crux from BCS.
      The furnace is double wall steel with 2" frax between.
      The inner face is steel. There is about 3" around the
      sides of the crux and 10" overhead to the cover.

      Q1-Is the inside of the furnace too big for the crux?
      Q2- Should the inner face of the furnace be refractory
      rather than steel?
      Q3- what's the trick to balancing the fuel/air for the hottest burn?
      Q4- there is little heat loss through the furnace walls, as they
      are just warm to the touch.
      Q5- what do you use for a dross skimmer?
      My antique steel slotted spoon melted / dissolved.

      Q6- What is the proper technique to "burn out" a wax
      investment? I blew mine up in the furnace... so I figure
      that is NOT the right way to do it.

      Thanks
      lance
      ++++

      [Non-text portions of this message have been removed]
    • Dennis
      Some quick answers, The temperature has to be just hotter than where you want to go. It is the heat, usually measured in BTUs, is what melts the metal. A 3000
      Message 2 of 12 , Nov 6, 2010
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        Some quick answers,

        The temperature has to be just hotter than where you want to go. It is the
        heat, usually measured in BTUs, is what melts the metal. A 3000 degree flame
        with little heat wouldn't melt aluminum, but a 2200 degree flame with lots
        of heat would. I use a bbq regulator to melt aluminum in a #4 crucible, but
        anything larger is going to require more gas flow.

        Q1: The distance between the crucible and the furnace should be just enough
        to get the tongs in. In other words, fairly small.
        Q2: Yes, the steel interior just carries away the heat.
        Q5: Your dross skimmer was probably pewter or tin if it melted in aluminum.
        Q6: Slowly, when melting out a wax investment, the temperature needs to be
        raised slowly to allow the free water trapped in the investment to migrate
        to the outside to be evaporated. Then the bound water (dotH2O) needs to
        separate and migrate out and be evaporated. That is the reason furnaces used
        for burn out have programmable controllers with up to 6 stages of time and
        temperature control. Heating to fast causes the trapped water to turn to
        steam, going bang. Burn out for the first stages is measured in hours.

        Dennis Cranston



        -----Original Message-----
        From: hobbicast@yahoogroups.com [mailto:hobbicast@yahoogroups.com] On Behalf
        Of wheezer
        Sent: Saturday, November 06, 2010 12:26 PM
        To: hobbicast@yahoogroups.com
        Subject: [hobbicast] Need help balancing burner / furnace

        Hello Group,

        After years of collecting parts, rebuilding the furnace x3
        and testing various burner designs, I have FINALLY
        started to melt some aluminum.

        I built a forge to make the lifting and pouring tongs
        as well as other tools.

        So now that I have some fire under my belt,
        I have a few questions.

        A- My furnace burner flame Temp is >>2000F, but it
        takes >> 20 minutes to get the first melt from cold.
        I am using a modified side arm burner w/ propane,
        venturi aspirated. I have a low pressure propane
        regulator set for about 10 psi. Often, the flame will
        sputter unless I close down the air inlet.
        Then the flame gets cooler.

        I am using an A20 clay-graphite crux from BCS.
        The furnace is double wall steel with 2" frax between.
        The inner face is steel. There is about 3" around the
        sides of the crux and 10" overhead to the cover.

        Q1-Is the inside of the furnace too big for the crux?
        Q2- Should the inner face of the furnace be refractory
        rather than steel?
        Q3- what's the trick to balancing the fuel/air for the hottest burn?
        Q4- there is little heat loss through the furnace walls, as they
        are just warm to the touch.
        Q5- what do you use for a dross skimmer?
        My antique steel slotted spoon melted / dissolved.

        Q6- What is the proper technique to "burn out" a wax
        investment? I blew mine up in the furnace... so I figure
        that is NOT the right way to do it.

        Thanks
        lance
        ++++

        [Non-text portions of this message have been removed]



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        this list does not accept attachments.

        Files area and list services are at:
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        check out these two affiliated sites:
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      • Scrolling8
        Q1-Is the inside of the furnace too big for the crux? Its about the right size. Q2- Should the inner face of the furnace be refractory rather than steel?
        Message 3 of 12 , Nov 6, 2010
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          Q1-Is the inside of the furnace too big for the crux?

          Its about the right size.

          Q2- Should the inner face of the furnace be refractory
          rather than steel?

          Refractory would be preferred.

          Q3- what's the trick to balancing the fuel/air for the hottest burn?

          You say you have a low pressure regulator, when in fact you have a high pressure regulator. Low goes to about 2 1/2 psi, high can go up to about 15 psi.

          Think about what happens when you reduce your air flow. You provide the air so that your fuel is provided with enough oxygen to burn therefore producing heat. So when you reduced your air flow you cut its source of oxygen, hence the flame went cold because gas doesn't burn without oxygen. What you should try doing is reduce the gas pressure slowly bringing the pressure down until you see the temp rise. You are now getting more complete combustion inside the furnace. Note the fine tuning of the flame should be done at night when you can see the amount of flame coming through the hole in the top of the furnace. Your cover does completely cover the top of the furnace except for a 2-1/2 to 3" hole centered on the top? Your flow out this hole is what is called dragons breath by some and should be a nice steady blue flame without the appearance of orange at all. If evidence of a gap between the top of the furnace and a reignition of the flame above the top of the furnace is occuring you are infact running out of oxygen inside your furnace and unburned fuel is being carried out the top of the furnace and reigniting, thereby wasting much of your heat as it escapes. You should play with this until you find the sweet spot and then mark your gage so that you can repeat this during the day.

          Q4- there is little heat loss through the furnace walls, as they
          are just warm to the touch.

          This is good, but metal carries away heat. The bottom should also be insulated

          Q5- what do you use for a dross skimmer?
          My antique steel slotted spoon melted / dissolved.

          You are not a witch you don't immerse your dross skimmer into the alluminum and stir it, you skim the surface and get rid of the top dross. No stirring of any kind.

          Q6- What is the proper technique to "burn out" a wax
          investment? I blew mine up in the furnace... so I figure
          that is NOT the right way to do it.

          Slowly, very slowly take your time and be sure you melt it all out. If you didn't like the the blown up mold while trying to do a burnout you will like the explosion even less after you have poured molten metal into it. Remember when pouring only the two people doing the pouring should be amoungst the molds. If you have to make a hasty exit you don't want to waste time screaming at people to get out of your way. I would recommend finding and reading more books on the topic. This is something that you should no more about and books do shed more light on the subject.




          [Non-text portions of this message have been removed]
        • wheezer
          Group, Thank you for your input. I plan to make these mods, please advise if you see a problem. Q1-- raise the crux up to reduce empty space tween crux and
          Message 4 of 12 , Nov 6, 2010
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            Group,

            Thank you for your input.

            I plan to make these mods, please
            advise if you see a problem.

            Q1-- raise the crux up to reduce empty space
            'tween crux and cover

            Q2--remove steel liner and add another layer of frax
            coat frax with sodium silicate and harden

            Q3-- this one still has some questions:

            1- I have NO flame coming out of the 3" cover hole.
            What does that mean?

            2- re needle valve at burner
            I checked local hardware store, no such thing
            I bought a 1/2" gate valve instead
            Do you make your own needle valve, if so picture or link?
            If you buy them, a source?

            3- "... You also need a full flow tail piece on the regulator. It
            will have a large hole in vice a very small one. The hole through
            the tail piece should be at least 1/4 inch If it is not drill it
            out. ... "
            I don't understand the lingo here... "tail piece" "in vice a..."
            "... hole through the tail piece.."
            Please clarify.

            Q4-- I will better insulate the bottom when I raise the crux and
            remove the liner.


            Q5--I have used a green stick to stir the melt, works very well, but
            nothing sticks to it.
            I WAS stirring with the skimmer, my bad.
            I will switch to SS.

            Q6-- Kitchen oven = not possible, but I do have a Paragon sectional
            electric kiln waiting to be rewired and a TC built for it. Any
            suggestions for this winter project?

            Amy, re the timing:
            6-8 hours at what temp? Wax MP + ?? extra degrees?
            Then raise temp from above to 1000F over 4 hours, then cook for 20
            hours at 1000 F. Is this correct?


            [Non-text portions of this message have been removed]
          • Dennis
            Q6:Quoting from Centrifugal or Lost Wax Jewelry Casting by Murray Bovin, a text that seems to be a good starting point, a commercial burnout cycle is as
            Message 5 of 12 , Nov 6, 2010
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              Q6:Quoting from 'Centrifugal or Lost Wax Jewelry Casting' by Murray Bovin, a
              text that seems to be a good starting point, a commercial burnout cycle is
              as follows:
              1 hour at 250
              1 hour to 600 (the 'to' refers to ramping up the temperature over the time
              period)
              1 hour to 1000
              1 hour to 1350
              2 hours hold at 1350
              1 hour drop to 1150
              1 hour drop to 1050
              1 hour drop to proper casting temperatures.

              This is probably a very conservative schedule. A comment was in the book
              about never exceeding 1450 degrees as the investment will start breaking
              down physically. If you use commercial investment, there may be a schedule
              recommendation either packaged with the investment or on the manufactures
              website.

              Good luck, I'm no expert, I have done lost wax just a few times so am still
              learning from the books.


              Dennis Cranston


              -----Original Message-----
              From: hobbicast@yahoogroups.com [mailto:hobbicast@yahoogroups.com] On Behalf
              Of wheezer
              Sent: Saturday, November 06, 2010 9:17 PM
              To: hobbicast@yahoogroups.com
              Subject: Re: [hobbicast] THANK YOU for help balancing burner / furnace

              Group,

              Thank you for your input.

              I plan to make these mods, please
              advise if you see a problem.

              Q1-- raise the crux up to reduce empty space
              'tween crux and cover

              Q2--remove steel liner and add another layer of frax
              coat frax with sodium silicate and harden

              Q3-- this one still has some questions:

              1- I have NO flame coming out of the 3" cover hole.
              What does that mean?

              2- re needle valve at burner
              I checked local hardware store, no such thing
              I bought a 1/2" gate valve instead
              Do you make your own needle valve, if so picture or link?
              If you buy them, a source?

              3- "... You also need a full flow tail piece on the regulator. It
              will have a large hole in vice a very small one. The hole through
              the tail piece should be at least 1/4 inch If it is not drill it
              out. ... "
              I don't understand the lingo here... "tail piece" "in vice a..."

              "... hole through the tail piece.."
              Please clarify.

              Q4-- I will better insulate the bottom when I raise the crux and
              remove the liner.


              Q5--I have used a green stick to stir the melt, works very well, but
              nothing sticks to it.
              I WAS stirring with the skimmer, my bad.
              I will switch to SS.

              Q6-- Kitchen oven = not possible, but I do have a Paragon sectional
              electric kiln waiting to be rewired and a TC built for it. Any
              suggestions for this winter project?

              Amy, re the timing:
              6-8 hours at what temp? Wax MP + ?? extra degrees?
              Then raise temp from above to 1000F over 4 hours, then cook for 20
              hours at 1000 F. Is this correct?


              [Non-text portions of this message have been removed]



              ------------------------------------

              For discussion of Metal Casting and related issues
              this list does not accept attachments.

              Files area and list services are at:
              http://groups.yahoo.com/group/hobbicast

              For additional files and photos and off topic discussions
              check out these two affiliated sites:
              http://groups.yahoo.com/group/sandcrabs
              http://groups.yahoo.com/group/Hobbicast1

              Please visit our sponsor: Budget Casting Supply
              http://budgetcastingsupply.com/

              List Owner:
              owly@...

              Yahoo! Groups Links
            • Lance
              Dennis, I am using POP and sand. I ll try this once I get the TC on the electrokiln made. lance ++++ ... [Non-text portions of this message have been removed]
              Message 6 of 12 , Nov 6, 2010
              • 0 Attachment
                Dennis,

                I am using POP and sand.

                I'll try this once I get the TC on the electrokiln made.

                lance
                ++++
                On Nov 6, 2010, at 11:16 PM, Dennis wrote:

                > Q6:Quoting from 'Centrifugal or Lost Wax Jewelry Casting' by Murray
                > Bovin, a
                > text that seems to be a good starting point, a commercial burnout
                > cycle is
                > as follows:
                > 1 hour at 250
                > 1 hour to 600 (the 'to' refers to ramping up the temperature over
                > the time
                > period)
                > 1 hour to 1000
                > 1 hour to 1350
                > 2 hours hold at 1350
                > 1 hour drop to 1150
                > 1 hour drop to 1050
                > 1 hour drop to proper casting temperatures.



                [Non-text portions of this message have been removed]
              • abascirocco
                There are three things you re trying to achieve with a burn out, first and most obvious is to burn out any residual wax, second is to drive off any chemically
                Message 7 of 12 , Nov 7, 2010
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                  There are three things you're trying to achieve with a burn out, first and most obvious is to burn out any residual wax, second is to drive off any chemically bound up water in the investment, for a plaster based investment, the temperature required for this is fairly low only 170-190°C and finally, to bring the mold close to your metal's pouring temperature to reduce thermal shock and ensure a complete fill.

                  Any burn out method and schedule that achieves these goals without damaging the mold will work, POP and sand is fairly forgiving in this regard, I once successfully used a propane BBQ as a burnout oven for a POP and sand mold.



                  --- In hobbicast@yahoogroups.com, Lance <gbof@...> wrote:
                  >
                  > Dennis,
                  >
                  > I am using POP and sand.
                  >
                  > I'll try this once I get the TC on the electrokiln made.
                  >
                  > lance
                  > ++++
                  > On Nov 6, 2010, at 11:16 PM, Dennis wrote:
                  >
                  > > Q6:Quoting from 'Centrifugal or Lost Wax Jewelry Casting' by Murray
                  > > Bovin, a
                  > > text that seems to be a good starting point, a commercial burnout
                  > > cycle is
                  > > as follows:
                  > > 1 hour at 250
                  > > 1 hour to 600 (the 'to' refers to ramping up the temperature over
                  > > the time
                  > > period)
                  > > 1 hour to 1000
                  > > 1 hour to 1350
                  > > 2 hours hold at 1350
                  > > 1 hour drop to 1150
                  > > 1 hour drop to 1050
                  > > 1 hour drop to proper casting temperatures.
                  >
                  >
                  >
                  > [Non-text portions of this message have been removed]
                  >
                • michael.a.porter@comcast.net
                  Wheezer, No flame exiting exhaust hole means you are getting complete combustion within the furnace. When you take the temperature higher, you may see a small
                  Message 8 of 12 , Nov 7, 2010
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                    Wheezer,
                    No flame exiting exhaust hole means you are getting complete combustion within the furnace. When you take the temperature higher, you may see a small yellow exhaust flame that is of no concearn.

                    You can find a needle valve at Larry Zoeller Forge: http://zoellerforge.com/flare.html , Ellis Knifeworks ,http://elliscustomknifeworks.hightemptools.com/valves.html Amazon.com at: http://www.amazon.com/Weksler-BBV4-Needle-Valve/dp/B000LDD4PY/ref=sr_1_fkmr1_1?ie=UTF8&qid=1289149258&sr=8-1-fkmr1 . My personal favorite is this valve: http://www.bestmaterials.com/detail.aspx?ID=15723 It is offered for sale on several websites at the quoted price.

                    Gate valves are more commonly used to regulate air flow in fan-blown burners.

                    The tail piece on a regulator is the connector fitting between regulator and gas cylinder; they are available from numerous online sources, such as Mr. Heater. Google search example: http://www.easternmarineoutlet.com/Heavy-Duty-Propane-POL-Plug-Adapter-59203/source=googleps/ This one makes a good choice.
                    Frankenburner

                    ----- Original Message -----
                    From: wheezer <wheezer606@...>
                    To: hobbicast@yahoogroups.com
                    Sent: Sun, 07 Nov 2010 02:16:41 -0000 (UTC)
                    Subject: Re: [hobbicast] THANK YOU for help balancing burner / furnace













                    Group,



                    Thank you for your input.



                    I plan to make these mods, please


                    advise if you see a problem.



                    Q1-- raise the crux up to reduce empty space


                    'tween crux and cover



                    Q2--remove steel liner and add another layer of frax


                    coat frax with sodium silicate and harden



                    Q3-- this one still has some questions:



                    1- I have NO flame coming out of the 3" cover hole.


                    What does that mean?



                    2- re needle valve at burner


                    I checked local hardware store, no such thing


                    I bought a 1/2" gate valve instead


                    Do you make your own needle valve, if so picture or link?


                    If you buy them, a source?



                    3- "... You also need a full flow tail piece on the regulator. It


                    will have a large hole in vice a very small one. The hole through


                    the tail piece should be at least 1/4 inch If it is not drill it


                    out. ... "


                    I don't understand the lingo here... "tail piece" "in vice a..."


                    "... hole through the tail piece.."


                    Please clarify.



                    Q4-- I will better insulate the bottom when I raise the crux and


                    remove the liner.



                    Q5--I have used a green stick to stir the melt, works very well, but


                    nothing sticks to it.


                    I WAS stirring with the skimmer, my bad.


                    I will switch to SS.



                    Q6-- Kitchen oven = not possible, but I do have a Paragon sectional


                    electric kiln waiting to be rewired and a TC built for it. Any


                    suggestions for this winter project?



                    Amy, re the timing:


                    6-8 hours at what temp? Wax MP + ?? extra degrees?


                    Then raise temp from above to 1000F over 4 hours, then cook for 20


                    hours at 1000 F. Is this correct?




                    [Non-text portions of this message have been removed]








                    [Non-text portions of this message have been removed]
                  • Scrolling8
                    ... From: wheezer To: hobbicast Sent: Sat, Nov 6, 2010 9:16 pm Subject: Re: [hobbicast] THANK YOU for help
                    Message 9 of 12 , Nov 7, 2010
                    • 0 Attachment
                      -----Original Message-----
                      From: wheezer <wheezer606@...>
                      To: hobbicast <hobbicast@yahoogroups.com>
                      Sent: Sat, Nov 6, 2010 9:16 pm
                      Subject: Re: [hobbicast] THANK YOU for help balancing burner / furnace




                      Group,

                      Thank you for your input.

                      I plan to make these mods, please
                      advise if you see a problem.

                      Q1-- raise the crux up to reduce empty space
                      'tween crux and cover

                      Q2--remove steel liner and add another layer of frax
                      coat frax with sodium silicate and harden

                      ** add a hard refractory brick bottom and when you put your crucible in the furnace or oven place a piece of cardboard down on top of the brick so that if something spill from the crucible it doesn't glue itself down to the bottom just the burnt cardboard. You don't want your crucible stuck to the bottom.

                      Q3-- this one still has some questions:

                      1- I have NO flame coming out of the 3" cover hole.
                      What does that mean?

                      Where does your oven or furnace exhaust go. It should all come out the top whole. If you have no flame coming out the means you have excess oxygen inside your oven or crucible. You should increase your fuel pressure or decrease your air to get just a hint of flame coming out the hole in the top.

                      2- re needle valve at burner
                      I checked local hardware store, no such thing
                      I bought a 1/2" gate valve instead
                      Do you make your own needle valve, if so picture or link?
                      If you buy them, a source?

                      Different burners use different devices to control the gas flow. Yours might not need a needle valve.

                      3- "... You also need a full flow tail piece on the regulator. It
                      will have a large hole in vice a very small one. The hole through
                      the tail piece should be at least 1/4 inch If it is not drill it
                      out. ... "
                      I don't understand the lingo here... "tail piece" "in vice a..."
                      "... hole through the tail piece.."
                      Please clarify.

                      Q4-- I will better insulate the bottom when I raise the crux and
                      remove the liner.

                      Q5--I have used a green stick to stir the melt, works very well, but
                      nothing sticks to it.
                      I WAS stirring with the skimmer, my bad.
                      I will switch to SS.

                      Very minimal stirring should be done. Skimming yes, Stirring no.

                      Q6-- Kitchen oven = not possible, but I do have a Paragon sectional
                      electric kiln waiting to be rewired and a TC built for it. Any
                      suggestions for this winter project?

                      Your meltout/burnout process can vari depending upon the size of your finished molds. Small jewelry need a different process that if make larger artwart of replacement parts for restoring old power units. Put your thinking cap on. Some of these answers are quite specific to a certain types of molds. For example artistic mold using lost wax method then coated in ceramic have a high chance of cracking because wax has a tendancy to expand when heated thus cracking the ceramic mold. Many artists use and old dip stick style heating element to melt out the center of the wax before going to the heat op stage and melting the wax out. This part is done at a relatively low temp just below 200 degrees. Burnout ofter being sure that the meltout portion is complete can be carried out at 300 to 600 degrees. Preheat prior to pouring would be at the higher temp.
                      Once again read, read, read, and learn from others people misfortune. Then do, do, do, and learn from your own.

                      Amy, re the timing:
                      6-8 hours at what temp? Wax MP + ?? extra degrees?
                      Then raise temp from above to 1000F over 4 hours, then cook for 20
                      hours at 1000 F. Is this correct?


                      [Non-text portions of this message have been removed]







                      [Non-text portions of this message have been removed]
                    • David
                      Needle valve go to a welding supply they will have one
                      Message 10 of 12 , Nov 7, 2010
                      • 0 Attachment
                        Needle valve go to a welding supply they will have one
                        --- In hobbicast@yahoogroups.com, wheezer <wheezer606@...> wrote:
                        >
                        > Group,
                        >
                        > Thank you for your input.
                        >
                        > I plan to make these mods, please
                        > advise if you see a problem.
                        >
                        > Q1-- raise the crux up to reduce empty space
                        > 'tween crux and cover
                        >
                        > Q2--remove steel liner and add another layer of frax
                        > coat frax with sodium silicate and harden
                        >
                        > Q3-- this one still has some questions:
                        >
                        > 1- I have NO flame coming out of the 3" cover hole.
                        > What does that mean?
                        >
                        > 2- re needle valve at burner
                        > I checked local hardware store, no such thing
                        > I bought a 1/2" gate valve instead
                        > Do you make your own needle valve, if so picture or link?
                        > If you buy them, a source?
                        >
                        > 3- "... You also need a full flow tail piece on the regulator. It
                        > will have a large hole in vice a very small one. The hole through
                        > the tail piece should be at least 1/4 inch If it is not drill it
                        > out. ... "
                        > I don't understand the lingo here... "tail piece" "in vice a..."
                        > "... hole through the tail piece.."
                        > Please clarify.
                        >
                        > Q4-- I will better insulate the bottom when I raise the crux and
                        > remove the liner.
                        >
                        >
                        > Q5--I have used a green stick to stir the melt, works very well, but
                        > nothing sticks to it.
                        > I WAS stirring with the skimmer, my bad.
                        > I will switch to SS.
                        >
                        > Q6-- Kitchen oven = not possible, but I do have a Paragon sectional
                        > electric kiln waiting to be rewired and a TC built for it. Any
                        > suggestions for this winter project?
                        >
                        > Amy, re the timing:
                        > 6-8 hours at what temp? Wax MP + ?? extra degrees?
                        > Then raise temp from above to 1000F over 4 hours, then cook for 20
                        > hours at 1000 F. Is this correct?
                        >
                        >
                        > [Non-text portions of this message have been removed]
                        >
                      • David
                        you can get the same parts at any welding supply store.
                        Message 11 of 12 , Nov 7, 2010
                        • 0 Attachment
                          you can get the same parts at any welding supply store.

                          --- In hobbicast@yahoogroups.com, michael.a.porter@... wrote:
                          >
                          > Wheezer,
                          > No flame exiting exhaust hole means you are getting complete combustion within the furnace. When you take the temperature higher, you may see a small yellow exhaust flame that is of no concearn.
                          >
                          > You can find a needle valve at Larry Zoeller Forge: http://zoellerforge.com/flare.html , Ellis Knifeworks ,http://elliscustomknifeworks.hightemptools.com/valves.html Amazon.com at: http://www.amazon.com/Weksler-BBV4-Needle-Valve/dp/B000LDD4PY/ref=sr_1_fkmr1_1?ie=UTF8&qid=1289149258&sr=8-1-fkmr1 . My personal favorite is this valve: http://www.bestmaterials.com/detail.aspx?ID=15723 It is offered for sale on several websites at the quoted price.
                          >
                          > Gate valves are more commonly used to regulate air flow in fan-blown burners.
                          >
                          > The tail piece on a regulator is the connector fitting between regulator and gas cylinder; they are available from numerous online sources, such as Mr. Heater. Google search example: http://www.easternmarineoutlet.com/Heavy-Duty-Propane-POL-Plug-Adapter-59203/source=googleps/ This one makes a good choice.
                          > Frankenburner
                          >
                          > ----- Original Message -----
                          > From: wheezer <wheezer606@...>
                          > To: hobbicast@yahoogroups.com
                          > Sent: Sun, 07 Nov 2010 02:16:41 -0000 (UTC)
                          > Subject: Re: [hobbicast] THANK YOU for help balancing burner / furnace
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          > Group,
                          >
                          >
                          >
                          > Thank you for your input.
                          >
                          >
                          >
                          > I plan to make these mods, please
                          >
                          >
                          > advise if you see a problem.
                          >
                          >
                          >
                          > Q1-- raise the crux up to reduce empty space
                          >
                          >
                          > 'tween crux and cover
                          >
                          >
                          >
                          > Q2--remove steel liner and add another layer of frax
                          >
                          >
                          > coat frax with sodium silicate and harden
                          >
                          >
                          >
                          > Q3-- this one still has some questions:
                          >
                          >
                          >
                          > 1- I have NO flame coming out of the 3" cover hole.
                          >
                          >
                          > What does that mean?
                          >
                          >
                          >
                          > 2- re needle valve at burner
                          >
                          >
                          > I checked local hardware store, no such thing
                          >
                          >
                          > I bought a 1/2" gate valve instead
                          >
                          >
                          > Do you make your own needle valve, if so picture or link?
                          >
                          >
                          > If you buy them, a source?
                          >
                          >
                          >
                          > 3- "... You also need a full flow tail piece on the regulator. It
                          >
                          >
                          > will have a large hole in vice a very small one. The hole through
                          >
                          >
                          > the tail piece should be at least 1/4 inch If it is not drill it
                          >
                          >
                          > out. ... "
                          >
                          >
                          > I don't understand the lingo here... "tail piece" "in vice a..."
                          >
                          >
                          > "... hole through the tail piece.."
                          >
                          >
                          > Please clarify.
                          >
                          >
                          >
                          > Q4-- I will better insulate the bottom when I raise the crux and
                          >
                          >
                          > remove the liner.
                          >
                          >
                          >
                          > Q5--I have used a green stick to stir the melt, works very well, but
                          >
                          >
                          > nothing sticks to it.
                          >
                          >
                          > I WAS stirring with the skimmer, my bad.
                          >
                          >
                          > I will switch to SS.
                          >
                          >
                          >
                          > Q6-- Kitchen oven = not possible, but I do have a Paragon sectional
                          >
                          >
                          > electric kiln waiting to be rewired and a TC built for it. Any
                          >
                          >
                          > suggestions for this winter project?
                          >
                          >
                          >
                          > Amy, re the timing:
                          >
                          >
                          > 6-8 hours at what temp? Wax MP + ?? extra degrees?
                          >
                          >
                          > Then raise temp from above to 1000F over 4 hours, then cook for 20
                          >
                          >
                          > hours at 1000 F. Is this correct?
                          >
                          >
                          >
                          >
                          > [Non-text portions of this message have been removed]
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          > [Non-text portions of this message have been removed]
                          >
                        • David
                          sorry forgot, you can also get the same parts at any large propane supply. along with high pressure propane regulators that go higher than 35 PSI.
                          Message 12 of 12 , Nov 7, 2010
                          • 0 Attachment
                            sorry forgot, you can also get the same parts at any large propane supply. along with high pressure propane regulators that go higher than 35 PSI.

                            --- In hobbicast@yahoogroups.com, michael.a.porter@... wrote:
                            >
                            > Wheezer,
                            > No flame exiting exhaust hole means you are getting complete combustion within the furnace. When you take the temperature higher, you may see a small yellow exhaust flame that is of no concearn.
                            >
                            > You can find a needle valve at Larry Zoeller Forge: http://zoellerforge.com/flare.html , Ellis Knifeworks ,http://elliscustomknifeworks.hightemptools.com/valves.html Amazon.com at: http://www.amazon.com/Weksler-BBV4-Needle-Valve/dp/B000LDD4PY/ref=sr_1_fkmr1_1?ie=UTF8&qid=1289149258&sr=8-1-fkmr1 . My personal favorite is this valve: http://www.bestmaterials.com/detail.aspx?ID=15723 It is offered for sale on several websites at the quoted price.
                            >
                            > Gate valves are more commonly used to regulate air flow in fan-blown burners.
                            >
                            > The tail piece on a regulator is the connector fitting between regulator and gas cylinder; they are available from numerous online sources, such as Mr. Heater. Google search example: http://www.easternmarineoutlet.com/Heavy-Duty-Propane-POL-Plug-Adapter-59203/source=googleps/ This one makes a good choice.
                            > Frankenburner
                            >
                            > ----- Original Message -----
                            > From: wheezer <wheezer606@...>
                            > To: hobbicast@yahoogroups.com
                            > Sent: Sun, 07 Nov 2010 02:16:41 -0000 (UTC)
                            > Subject: Re: [hobbicast] THANK YOU for help balancing burner / furnace
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            > Group,
                            >
                            >
                            >
                            > Thank you for your input.
                            >
                            >
                            >
                            > I plan to make these mods, please
                            >
                            >
                            > advise if you see a problem.
                            >
                            >
                            >
                            > Q1-- raise the crux up to reduce empty space
                            >
                            >
                            > 'tween crux and cover
                            >
                            >
                            >
                            > Q2--remove steel liner and add another layer of frax
                            >
                            >
                            > coat frax with sodium silicate and harden
                            >
                            >
                            >
                            > Q3-- this one still has some questions:
                            >
                            >
                            >
                            > 1- I have NO flame coming out of the 3" cover hole.
                            >
                            >
                            > What does that mean?
                            >
                            >
                            >
                            > 2- re needle valve at burner
                            >
                            >
                            > I checked local hardware store, no such thing
                            >
                            >
                            > I bought a 1/2" gate valve instead
                            >
                            >
                            > Do you make your own needle valve, if so picture or link?
                            >
                            >
                            > If you buy them, a source?
                            >
                            >
                            >
                            > 3- "... You also need a full flow tail piece on the regulator. It
                            >
                            >
                            > will have a large hole in vice a very small one. The hole through
                            >
                            >
                            > the tail piece should be at least 1/4 inch If it is not drill it
                            >
                            >
                            > out. ... "
                            >
                            >
                            > I don't understand the lingo here... "tail piece" "in vice a..."
                            >
                            >
                            > "... hole through the tail piece.."
                            >
                            >
                            > Please clarify.
                            >
                            >
                            >
                            > Q4-- I will better insulate the bottom when I raise the crux and
                            >
                            >
                            > remove the liner.
                            >
                            >
                            >
                            > Q5--I have used a green stick to stir the melt, works very well, but
                            >
                            >
                            > nothing sticks to it.
                            >
                            >
                            > I WAS stirring with the skimmer, my bad.
                            >
                            >
                            > I will switch to SS.
                            >
                            >
                            >
                            > Q6-- Kitchen oven = not possible, but I do have a Paragon sectional
                            >
                            >
                            > electric kiln waiting to be rewired and a TC built for it. Any
                            >
                            >
                            > suggestions for this winter project?
                            >
                            >
                            >
                            > Amy, re the timing:
                            >
                            >
                            > 6-8 hours at what temp? Wax MP + ?? extra degrees?
                            >
                            >
                            > Then raise temp from above to 1000F over 4 hours, then cook for 20
                            >
                            >
                            > hours at 1000 F. Is this correct?
                            >
                            >
                            >
                            >
                            > [Non-text portions of this message have been removed]
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            >
                            > [Non-text portions of this message have been removed]
                            >
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