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Thermite for casting

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  • John Norman
    Here is a web page where someone used Thermite (the Iron Oxide was salvaged by running a magnet through sand) to cast an iron chain link. Check out:
    Message 1 of 18 , Oct 31, 2004
      Here is a web page where someone used Thermite (the Iron Oxide was salvaged by
      running a magnet through sand) to cast an iron chain link. Check out:

      http://www.theodoregray.com/PeriodicTable/Elements/026/index.s7.html#sample17

      There is also a video of the casting on this site.


      John N.
    • Charles
      ... is a bad ... through ... bottom of your ... in the ... for this. ... nothing ... I understand that. I think thermite, like you said, is supposed to burn
      Message 2 of 18 , Nov 1, 2004
        --- In hobbicast@yahoogroups.com, "Greg Jahnke" <gjahnke@b...> wrote:
        >
        > Unless you have specifically designed your furnace for this, it
        is a bad
        > idea. The thermite will melt through the container it is in, burn
        through
        > the refractory at the bottom of the furnace, burn through the
        bottom of your
        > container, and continue in to the dirt underneath. Thermite burns
        in the
        > 5-6k degree range, your refractory is almost certainly not rated
        for this.
        > Thermite will burn through a 2000 degree fire brick like it is
        nothing
        >
        I understand that. I think thermite, like you said, is supposed to
        burn around 6500F. From what ive read when its burning it can easily
        give you second degree radiation burns. IF i did it I was going to
        use an infintesimal amount in a small metal cup over the "emergency"
        hole in the bottom of the furnace. Now im thinking if i ever get
        around to trying it ill do what someone said and just sprinkle it in
        among the charcoal or something in tiny amounts. Sortof a "booster
        shot" that activates once the furnace gets hot enough. Probably not
        though.
      • Charles
        ... of ... not ... turn ... crucible ... has ... Im really trying to change hte process and use charcoal only as a sortof continual, simple heat source .Im
        Message 3 of 18 , Nov 1, 2004
          --- In hobbicast@yahoogroups.com, "gene98329" <gene98329@c...> wrote:
          >
          > I've used charcoal for years to melt AL and even a few crucibles
          of
          > brass. If all your trying to do is ignite the charcoal fast why
          not
          > just use a chimney, which is a coffee can opened on one end as
          > normal and church key openings all around the other end along the
          > side. (use the key on the side of the can rather than the bottom)
          > This will get the charcoal going and then you can add into your
          > furnace with tongs around your crucible. instasll your lid and
          turn
          > on the blower. This should get a melt within 30-40 minutes at most?
          > I always use some thin sections of AL in the bottom of the
          crucible
          > to get the melt started (called a heel) then I add more AL that
          has
          > been preheating once the initial melt starts.
          > I have since converted to using propane as the newer NA burners
          > require no blower and do a great job in half the time!
          >
          > Only My $.02
          >
          > Gene

          Im really trying to change hte process and use charcoal only as a
          sortof continual, simple heat source .Im trying to find/design a
          kerosene burner atm (another low on the totem poll project) and am
          thinking of using charcoal in the furnace as a continual heat source
          to light the atomised kerosene. Seems safer too. Thanks for the
          advise.
        • Charles
          ... temperature to ... Melting the ... even though ... occur if ... aluminum ... and ... aluminum, ... generates ... There is a ... glass, ... thermite ... me
          Message 4 of 18 , Nov 1, 2004
            --- In hobbicast@yahoogroups.com, "Daniel C. Postellon"
            <postello@m...> wrote:
            > This is a possible accident. The reason that you need a high
            temperature to
            > start a thermite reaction is related to the oxide coating.
            Melting the
            > aluminum power releases liquid aluminum, which is very reactive,
            even though
            > the oxide is not. I suspect that the accidents are more likely to
            occur if
            > you machine aluminum with lots of rusty scrap around, the fresh
            aluminum
            > turnings might have some surfaces with little or no oxide coating,
            and
            > therefore more reactive. The thermite reaction basically burns
            aluminum,
            > using the oxide in iron oxide (rust) as a source of oxygen. It
            generates
            > enough heat to melt the iron which is released by the reaction.
            There is a
            > commercial firm that turns incinerator ash into a relatively inert
            glass,
            > using iron oxide and old aluminum cans as a heat source. Cheap
            thermite
            > should be possible, I just don't know how safe it would be. Let
            me know if
            > it works for you. I wouldn't mind trying it, but I don't want to
            be the
            > first.
            > Dan P.
            >

            Ive thoguht about it for years actually since i saw a movie where
            they used a thermite lance to burn through a bank vault. The idea
            that there was something that burned THAT hot set my young (at the
            time) mind blazing. Luckily i was wiser when i was younger.
            Eventually ill try to make some thermite. Maybe soon. I mostly make
            chips though so dont have a lot of fine aluminum or iron about.
            Strangely enough i cut a camshaft up to make a lathe spindle on my
            cheap pos bandsaww the other day and left LOTS of tiny Fe particle
            laying about. I was cutting some 6061 tonight and noticed the steel
            had turned to a pile of rust and thought about that safety report. I
            wasnt.. really worried.. but it did sit there in the back of my mind
            that i could experience a sudden burst of light and heat heh.

            BTW others have actually made thermite. Its not common but i found
            some web references.
          • Charles
            Sounds awesome. And easy to do. Well except for the explosion part.. ... salvaged by ...
            Message 5 of 18 , Nov 1, 2004
              Sounds awesome. And easy to do. Well except for the "explosion"
              part..

              --- In hobbicast@yahoogroups.com, "John Norman" <arclight@2...>
              wrote:
              >
              > Here is a web page where someone used Thermite (the Iron Oxide was
              salvaged by
              > running a magnet through sand) to cast an iron chain link. Check
              out:
              >
              >
              http://www.theodoregray.com/PeriodicTable/Elements/026/index.s7.html#
              sample17
              >
              > There is also a video of the casting on this site.
              >
              >
              > John N.
            • Daniel C Postellon
              The video is too big of a download for me. Look at his mini arc furnace, though. I guess this is proof that you can use a graphite mold for thermite. He
              Message 6 of 18 , Nov 1, 2004
                The video is too big of a download for me. Look at his mini arc furnace,
                though. I guess this is proof that you can use a graphite mold for
                thermite. He does have some impressive safety precautions. Dan P.
                >
                >
                > Here is a web page where someone used Thermite (the Iron Oxide was salvaged by
                > running a magnet through sand) to cast an iron chain link. Check out:
                >
                > http://www.theodoregray.com/PeriodicTable/Elements/026/index.s7.html#sample17
                >
                > There is also a video of the casting on this site.
                >
                >
                > John N.
                >
                >
                >
                >
                >
                > This list is for discussion of metal casting
                > and does not accept attachments. For off topic discussion and to share photos and stuff: join Sandcrabs by sending a blank message to: sandcrabs-subscribe@yahoogroups.com
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              • Charles
                No reason i can see you couldnt use a graphite mold. This guy is THROWING money at his projects though heh. Machined graphite molds for chain links? Heck we
                Message 7 of 18 , Nov 1, 2004
                  No reason i can see you couldnt use a graphite mold. This guy is
                  THROWING money at his projects though heh. Machined graphite molds
                  for chain links? Heck we bitch about spending an extra buck for a
                  bag of sand to cast with *grin*

                  His stuff did give me some neat ideas. I live near the railroad
                  tracks and you can literally walk up the tracks and pick up spikes
                  etc all day long they've discarded. Ive heard its superhard so
                  wouldnt want to machine it but... be kinda nice to machine a
                  graphite mold for 2" diameter x 24" steel bars etc etc etc :P

                  Only downside.. did you notice the finish on the castings? ROUGH. I
                  would have thought a graphite mold and that ultrahigh heat would
                  have made them smooth as glass.

                  --- In hobbicast@yahoogroups.com, "Daniel C Postellon"
                  <postello@m...> wrote:
                  > The video is too big of a download for me. Look at his mini arc
                  furnace,
                  > though. I guess this is proof that you can use a graphite mold
                  for
                  > thermite. He does have some impressive safety precautions. Dan
                  P.
                  > >
                  > >
                  > > Here is a web page where someone used Thermite (the Iron Oxide
                  was salvaged by
                  > > running a magnet through sand) to cast an iron chain link.
                  Check out:
                  > >
                  > >
                  http://www.theodoregray.com/PeriodicTable/Elements/026/index.s7.html#
                  sample17
                  > >
                  > > There is also a video of the casting on this site.
                  > >
                  > >
                  > > John N.
                  > >
                  > >
                  > >
                  > >
                  > >
                  > > This list is for discussion of metal casting
                  > > and does not accept attachments. For off topic discussion and
                  to share photos and stuff: join Sandcrabs by sending a blank
                  message to: sandcrabs-subscribe@yahoogroups.com
                  > > http://groups.yahoo.com/group/sandcrabs
                  > > Please visit our sponsor: Budget Casting Supply
                  > > http://budgetcastingsupply.com/
                  > >
                  > > Files area and list services are at:
                  > > http://groups.yahoo.com/group/hobbicast For problems that cannot
                  be otherwise solved contact the list owner by email:
                  > > owly@t...
                  > >
                  > >
                  > > Yahoo! Groups Links
                  > >
                  > >
                  > >
                  > >
                  > >
                  > >
                  > >
                  > >
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