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37623Re: [hobbicast] Re: Mobile Foundries...Does Anyone Have One?

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  • Stone Tool
    Apr 2, 2007
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      Lyle:
      A bit different pouring from a tilting furnace directly than doing it
      with a shank holding a crucible. Comfortable working height when
      handling heavy loads is hugely important........ As I mentioned, I
      feel that a bench for this purpose should be built so height can be
      adjusted anyway. The Hobbicast 1 group is set up specifically for
      posting photos and stuff..... in addition to space on the Yahoo photos
      sections for both groups....... I always like to have a look at people's
      projects.... A picture is worth.............

      H.W.

      Lyle wrote:
      > HW:
      > I can post a photo of my pouring bench. My biggest mistake was to
      > make it the same height as my molding bench thinking that I wouldn't
      > have to bend over to place the molds. Just move them sideways onto
      > the pour bench. Well, that works for aluminum but pouring 40 lbs of
      > bronze with a one man shank you need it to be lower. The one good
      > thing about my bench though is that it doubles as a welding bench by
      > flopping a 1/4" piece of plate steel onto it.
      > LL
      >
      > --- In hobbicast@yahoogroups.com, Stone Tool <owly@...> wrote:
      >> Lyle:
      >> My furnace is not of conventional design....... It uses a
      > small winch
      >> (hand crank) to lift the upper body..... this winch is a worm drive
      > unit
      >> and cannot freewheel. The furnace body is mounted to a carriage
      > which
      >> travels up a square tube post (2x2x.25). The carriage uses cable
      >> pulleys as wheels.... fairly large pulleys (5") with bronze
      > bushings
      >> that run on 1/2" round rod welded to opposite corners of the square
      > tube
      >> to make a track. A very simple way of making accurate smooth
      > tracking.
      >> The furnace body is mounted in a manner that allows it to swing
      > to
      >> the side on hinges completely away from the crucible leaving the
      >> crucible standing completely in the open atop the plinth. The
      > swing
      >> away is the crucial design feature which allows you to do anything
      > you
      >> want with nothing in the way.... but also ensures that if you knock
      > it
      >> over it is going to spill molten metal all over the floor rather
      > than
      >> into the furnace base which has a low wall around it after the body
      > is
      >> lifted off..... this wall extends only slightly above the level of
      > the
      >> plinth.
      >> The swing away system is designed in such a way that you
      > cannot swing
      >> it until the body is entirely clear of the crucible......and also
      > so
      >> that once it is swung at all it cannot come down as it is
      > physically
      >> blocked from coming down. There is absolutely no risk of dropping
      > the
      >> furnace body inadvertently....... none. Conventional tongs and
      > pouring
      >> shank work just as they would in an ordinary furnace except that
      > you do
      >> not have to lift the crucible up and out, just lift it an inch or
      > so and
      >> swing it over to set it in the pouring shank.
      >>
      >> The winter before last I built a large tilting furnace for an
      > artist
      >> friend...... I'm not sure how much aluminum it would contain but it
      >> would be measured in gallons. This furnace is skid mounted but
      > could
      >> easily be mounted on wheels. I uses a steel crucible which is more
      > or
      >> less permanently attached..... made from seamless steel tubing with
      > an
      >> angle iron pour spout that ends at a point that does not change as
      > the
      >> furnace is tilted. The furnace uses a rammed plastic refractory
      > base
      >> and lid with stabilized KOwool above the "blast zone".
      > Unfortunately
      >> the lady took one look at the monstrosity...... she wanted
      > BIG ..... and
      >> said she could not pour molten metal without hand pouring from a
      >> crucible, and that it was way too high off the floor to
      > work........ We
      >> had discussed the tilting design beforehand... but she is more than
      > a
      >> little fickle. My intent was to have a molding bench / sand
      > table /
      >> pouring bench at a decent working height where the mold would rest
      > which
      >> would roll easily and smoothly on the concrete floor to position
      > the
      >> sprue(s) under the spout leaving a few inches of pour height.....
      > and
      >> easy job.
      >> I built a suitably massive burner to feed the furnace.... a
      > burner that
      >> takes several 100 lb bottles to feed it, but have never fired the
      >> furnace...... the winch system for pouring turned out not to my
      >> satisfaction and needs redesign, but all that remains is to build
      > the
      >> molding bench and redesign the pouring mechanism. I walked away
      > in
      >> disgust after her rejection of the entire design....... but hope
      >> eventually to complete it for my own use....... It is capable of
      > doing
      >> some pretty large pours. It was my intent to do a crucible wash
      > to
      >> extend crucible life....... the crucible is fairly thick
      > steel....... I
      >> wonder how long it will take to burn out.........
      >> My thinking is that the bench would need to be adjustable
      > height.....
      >> not a real problem, and that the furnace would be intended to do
      >> multiple pours on one heat...... I can imagine what shrinkage
      > issues
      >> would show up with very large single pours.
      >> It's a shame that the furnace sits unfired........ someday!
      >>
      >> H.W.
      >>
      >> Lyle wrote:
      >>> Your right but he was talking about a Johnson furnace. I've
      > always
      >>> been a little leary (and perhaps wrongly) about lift up body
      >>> furnaces. Mental picture of taking the crucible out just as the
      > body
      >>> falls down onto the shank, crucible, etc. Of course, my lift out
      >>> furnace necessitates my melt being about crotch high when I lift
      > it
      >>> out and the shanks lock but there's some danger there too. I've
      > never
      >>> seen any shanks like your talking about except for those bent
      >>> lift/pour shanks that are used for smaller sized crucibles. ?They
      >>> wouldn't work for larger sizes though. I use one on a number 4
      >>> crucible I have for a little furnace.
      >>> How do you get your lift out shank around the crucible on that
      > lift
      >>> body furnace? Usually they grab the crucible from the top...?
      >>> LL
      >>>
      >>> --- In hobbicast@yahoogroups.com, Stone Tool <owly@> wrote:
      >>>> The height of the furnace ceases to be an issue if you have one
      >>> with a
      >>>> lift off body rather than using a "lift out" crucible. Mine is
      > on
      >>> iron
      >>>> wheels from some kind of farm implement..... about 18" diameter
      >>> steel
      >>>> spoke wheels actually, and the furnace body lifts clear of the
      > base
      >>> and
      >>>> swings out of the way. A tilting furnace might also work well
      > as a
      >>>> mobile unit. The next upgrade must be a lift & pour tong that
      > will
      >>>> allow you to lift the crucible directly off the plinth and pour
      >>> without
      >>>> setting it in a pouring shank. I envision a steel ring that you
      >>> drop
      >>>> over the crucible first, and jaws that close around the lower
      >>> portion.
      >>>> The idea of dropping the ring over first is to reduce the risk
      > of
      >>>> tipping the works over. Anybody seen anything like this?
      >>>>
      >>>> H.W.
      >>>>
      >>>> Lyle wrote:
      >>>>> I'll take a photo of my MIFCO 16 on a homemade cart that I've
      >>> welded up.
      >>>>> and post tonight. The biggest idea is to keep it as low as
      >>> possible.
      >>>>> LL
      >>>>>
      >>>>> --- In hobbicast@yahoogroups.com, "too_many_tools"
      >>> <too_many_tools@>
      >>>>> wrote:
      >>>>>> I have a Johnson foundry furnace that I would like to make
      >>> mobile and
      >>>>>> am looking for ideas as to how to build the foundry cart. I
      >>> envision
      >>>>>> having the furnace and supporting equipment on a cart where
      > the
      >>>>> foundry
      >>>>>> can be used and then stored.
      >>>>>>
      >>>>>> Has anyone done this?
      >>>>>>
      >>>>>> If so, I would appreciate your advice and pictures of how you
      >>>>>> implemented it.
      >>>>>>
      >>>>>> Thanks
      >>>>>>
      >>>>>> TMT
      >>>>>>
      >>>>>
      >>>>>
      >>>>> For discussion of Metal Casting and related issues
      >>>>> this list does not accept attachments.
      >>>>>
      >>>>> Files area and list services are at:
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      >>>>>
      >>>>> 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
      >>>>>
      >>>>>
      >>>>>
      >>>>>
      >>>
      >>>
      >>>
      >>> 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
      >>>
      >>>
      >>>
      >>>
      >
      >
      >
      >
      > 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
      >
      >
      >
      >
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