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Re: [hobbicast] Re: extrusions

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  • LLandstrom
    Anyone on this list in Minnesota? LL __________________________________________________ Do You Yahoo!? Yahoo! Photos - Share your holiday photos online!
    Message 1 of 8 , Jan 2, 2001
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      Anyone on this list in Minnesota?

      LL

      __________________________________________________
      Do You Yahoo!?
      Yahoo! Photos - Share your holiday photos online!
      http://photos.yahoo.com/
    • Jim Clary
      Dave, Yes to both questions. Ageing will increase the castings hardness whether natural, just let sit for several weeks, or artificially in an oven at elevated
      Message 2 of 8 , Jan 11, 2001
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        Dave,

        Yes to both questions. Ageing will increase the castings hardness whether
        natural, just let sit for several weeks, or artificially in an oven at
        elevated temperatures, I'd have to look it up but something around 350F
        comes to mind. Extrusion alloys usually have a higher brinell than as cast
        alloys and are easier to polish because of it.

        Matter of fact I'm in the middle of writing a book on making aluminum
        castings. It's a ways from being finished though. Thanks for the
        encouragement!

        Jim Clary

        ----- Original Message -----
        From: <davehughes2002@...>
        To: <hobbicast@egroups.com>
        Sent: Thursday, January 11, 2001 11:10 AM
        Subject: [hobbicast] Re: extrusions


        > Jim C.,
        >
        > Poured several small castings recently with the 535 you
        > suggested. Right on target, castings turned out great and produced a
        > very high luster machining straight out of the sand. Along with
        > these castings, I had to fabricate some polished trim-like pieces,
        > cutting to size Al. extrusions and buffing them out as well. I
        > noticed in comparison the castings were more tempremental than the
        > extruded on the polishing wheel - too much pressure and the surface
        > becomes lumpy in appearance, while the extruded can receive harder
        > pressure. This was as-cast, I didnt heat treat the castings what so
        > ever. Would the stress relieving or heat treat improve this
        > condition and become comprable to the extruded? I only ask this
        > because I would like to reduce cut down time on polishing, I may have
        > to make a bunch of these sets. I'm assuming this has to do with the
        > hardness of the alloy, extruded by virtue of its process being harder
        > than as-casted? Thanks again for your help. -dave
        >
        > Any comments from anyone much appreciated. Great posts guys;
        > learning tons.
        > Ps. Jim, you ever think about writing a book from all your
        > metallurgical knowledge, casting troubleshooting, etc.? I'd be first
        > in line to buy a copy.
        >
        > Pss. I read a post from a few months ago about someone wanting to
        > pour a 300 lb. CI cannon!!! Forgot who wrote the post, but if
        > whoever had the cannonballs to cast this howitzer could relay how it
        > went, I'd love to hear about it. Way out of my ordinance range; I'll
        > stick to the safe danger of dumping a #10 cruc.
        >
        >
        >
        > .--- In hobbicast@egroups.com, "Jim Clary" <jclary@s...> wrote:
        > > Dave,
        > >
        > > Most aluminum castings in sand could be poured around 1350 to 1375F
        > > regardless of which alloy you're using. Proper gating and venting is
        > > assumed. In most cases, if you can't get a good casting under 1400F
        > > something else is wrong, either the venting, gating or risers. Some
        > castings
        > > & alloys need to be poured higher or lower but that's a good place
        > to start
        > > from. This alloy, (535.2 "Almag 35"), does not require heat
        > treating, but
        > > stress relieving at 700-800F for 5 hours will improve it's already
        > very good
        > > properties. It is quite strong as cast, (40,000 tensile), has
        > excellent
        > > elongation, (13%), has good surface hardness, (70 Brinell), resists
        > > corrosion and takes a high polish. It has only fair casting
        > characteristics,
        > > (it, like other self ageing alloys such as Tenzalloy, Ternalloy,
        > etc.
        > > shrinks), but has excellent fluidity with no tendency toward hot
        > tearing,
        > > (the cracks you sometimes see at the inside of sharp corners of the
        > casting
        > > or between thin and thick sections). Use generous risers and
        > feeders and you
        > > should have no problem with it, especially if you're into making
        > plaques
        > > which I assume are flat and of uniform thickness.
        > >
        > > Jim Clary
        > >
        > >
        > > ----- Original Message -----
        > > From: <davehughes2002@y...>
        > > To: <hobbicast@egroups.com>
        > > Sent: Tuesday, January 02, 2001 11:16 AM
        > > Subject: [hobbicast] Re: extrusions
        > >
        > >
        > > > Jim C.,
        > > >
        > > > you've piqued my interest... what's the ideal pour temp. for
        > 535.2?
        > > > and any other special indications in allowance of the extra mag
        > > > content over 319, aside from your advice stated below? -dave...
        > > >
        > > > --- In hobbicast@egroups.com, "Jim Clary" <jclary@s...> wrote:
        > > > > Dave,
        > > > >
        > > > > LLandstrom had a good idea by mixing some high silicon content
        > > > alloy in with
        > > > > his extruded scrap. The silicon gives it flowability which
        > allows
        > > > it to fill
        > > > > the cavity quicker and to feed better. Might work for you too. I
        > > > would use
        > > > > 319 over 356 simply because 356 doesn't machine well unless it's
        > > > heat
        > > > > treated. 319, although dull, will machine pretty well in the as
        > > > cast state.
        > > > > They both will polish pretty well, better if both are heat
        > treated.
        > > > 535.2,
        > > > > an aluminum/magnesium alloy is better. It takes a high polish
        > and
        > > > resists
        > > > > corrosion which will keep the polished finish longer and,
        > happily,
        > > > Atlas
        > > > > Metal Sales (http://www.atlasmetal.com/) carries it.
        > > > >
        > > > > Jim Clary
        > > > >
        > > > > ----- Original Message -----
        > > > > From: <davehughes2002@y...>
        > > > > To: <hobbicast@egroups.com>
        > > > > Sent: Friday, December 29, 2000 12:34 PM
        > > > > Subject: [hobbicast] extrusions
        > > > >
        > > > >
        > > > > > Thanks for all your advice on the extrusion business. The
        > visual
        > > > > > results of the pour I described seemed not so much gaseous or
        > > > > > containing inclusions, but microscopic paralell cracks(i'm
        > > > assuming
        > > > > > within the entire cast to its core after machining down quite
        > > > deep to
        > > > > > test), like some esoteric alloying defect i thought someone
        > may
        > > > have
        > > > > > experienced. The charge was degassed, temp monitored, poured
        > > > quickly
        > > > > > etc. Bizarre, I hadnt seen anything similar in all my other
        > > > scrappy
        > > > > > pours. Regardless, i've been wanting to move up out of the
        > hit and
        > > > > > miss game into more consistant results and remove that crap
        > scrap
        > > > > > variable. I'll take your advice on staying with casting
        > alloys
        > > > for
        > > > > > the higher end stuff.(I'll save those extrusions for that pot
        > and
        > > > pan
        > > > > > set I was going to make for my mother in law.) I dont have
        > much
        > > > > > experience with 319 or 356 and was wondering which would be
        > more
        > > > > > suitable for decorative casting purpose only - good
        > machinability,
        > > > > > high buff, etc. If someone could relay their thoughts on
        > general
        > > > > > characteristics I may encounter between the two for this
        > purpose,
        > > > > > relative costs, and the like, I'd appreciate it. Thanks again
        > > > guys. -
        > > > > > dave.
        > > > > > P.s. read a message back a few pages, someone asking for a
        > plastic
        > > > > > lettering source with good draft. Try MONTROSE COLORS in IL.
        > > > 708-
        > > > > > 588-7910. They acquired all of Decor-teq, inc.'s of CA. stock
        > > > > > recently. They have several different fonts in injection-
        > molded
        > > > > > polypropylene I believe it is. Also a selection of artistic
        > > > rosettes
        > > > > > great for patterns. Hope this helps out.
        > > > > >
        > > > > >
        > > > > > Please visit our sponsor: Budget Casting Supply
        > > > > > http://budgetcastingsupply.com/
        > > > > >
        > > > > > The Home Foundrymen's Association website may be found here:
        > > > > http://members.xoom.com/HWilkinson/index.htm
        > > > > > It includes member project pages & links
        > > > > >
        > > > > > To unsubscribe from this group, send an email to:
        > > > > > hobbicast-unsubscribe@egroups.com
        > > > > >
        > > > > >
        > > > > >
        > > > > >
        > > >
        > > >
        > > > Please visit our sponsor: Budget Casting Supply
        > > > http://budgetcastingsupply.com/
        > > >
        > > > The Home Foundrymen's Association website may be found here:
        > > http://members.xoom.com/HWilkinson/index.htm
        > > > It includes member project pages & links
        > > >
        > > > To unsubscribe from this group, send an email to:
        > > > hobbicast-unsubscribe@egroups.com
        > > >
        > > >
        > > >
        > > >
        >
        >
        > Please visit our sponsor: Budget Casting Supply
        > http://budgetcastingsupply.com/
        >
        > The Home Foundrymen's Association website may be found here:
        http://members.xoom.com/HWilkinson/index.htm
        > It includes member project pages & links
        >
        > To unsubscribe from this group, send an email to:
        > hobbicast-unsubscribe@egroups.com
        >
        >
        >
      • davehughes2002@yahoo.com
        Jim C., Poured several small castings recently with the 535 you suggested. Right on target, castings turned out great and produced a very high luster
        Message 3 of 8 , Jan 11, 2001
        • 0 Attachment
          Jim C.,

          Poured several small castings recently with the 535 you
          suggested. Right on target, castings turned out great and produced a
          very high luster machining straight out of the sand. Along with
          these castings, I had to fabricate some polished trim-like pieces,
          cutting to size Al. extrusions and buffing them out as well. I
          noticed in comparison the castings were more tempremental than the
          extruded on the polishing wheel - too much pressure and the surface
          becomes lumpy in appearance, while the extruded can receive harder
          pressure. This was as-cast, I didnt heat treat the castings what so
          ever. Would the stress relieving or heat treat improve this
          condition and become comprable to the extruded? I only ask this
          because I would like to reduce cut down time on polishing, I may have
          to make a bunch of these sets. I'm assuming this has to do with the
          hardness of the alloy, extruded by virtue of its process being harder
          than as-casted? Thanks again for your help. -dave

          Any comments from anyone much appreciated. Great posts guys;
          learning tons.
          Ps. Jim, you ever think about writing a book from all your
          metallurgical knowledge, casting troubleshooting, etc.? I'd be first
          in line to buy a copy.

          Pss. I read a post from a few months ago about someone wanting to
          pour a 300 lb. CI cannon!!! Forgot who wrote the post, but if
          whoever had the cannonballs to cast this howitzer could relay how it
          went, I'd love to hear about it. Way out of my ordinance range; I'll
          stick to the safe danger of dumping a #10 cruc.



          .--- In hobbicast@egroups.com, "Jim Clary" <jclary@s...> wrote:
          > Dave,
          >
          > Most aluminum castings in sand could be poured around 1350 to 1375F
          > regardless of which alloy you're using. Proper gating and venting is
          > assumed. In most cases, if you can't get a good casting under 1400F
          > something else is wrong, either the venting, gating or risers. Some
          castings
          > & alloys need to be poured higher or lower but that's a good place
          to start
          > from. This alloy, (535.2 "Almag 35"), does not require heat
          treating, but
          > stress relieving at 700-800F for 5 hours will improve it's already
          very good
          > properties. It is quite strong as cast, (40,000 tensile), has
          excellent
          > elongation, (13%), has good surface hardness, (70 Brinell), resists
          > corrosion and takes a high polish. It has only fair casting
          characteristics,
          > (it, like other self ageing alloys such as Tenzalloy, Ternalloy,
          etc.
          > shrinks), but has excellent fluidity with no tendency toward hot
          tearing,
          > (the cracks you sometimes see at the inside of sharp corners of the
          casting
          > or between thin and thick sections). Use generous risers and
          feeders and you
          > should have no problem with it, especially if you're into making
          plaques
          > which I assume are flat and of uniform thickness.
          >
          > Jim Clary
          >
          >
          > ----- Original Message -----
          > From: <davehughes2002@y...>
          > To: <hobbicast@egroups.com>
          > Sent: Tuesday, January 02, 2001 11:16 AM
          > Subject: [hobbicast] Re: extrusions
          >
          >
          > > Jim C.,
          > >
          > > you've piqued my interest... what's the ideal pour temp. for
          535.2?
          > > and any other special indications in allowance of the extra mag
          > > content over 319, aside from your advice stated below? -dave...
          > >
          > > --- In hobbicast@egroups.com, "Jim Clary" <jclary@s...> wrote:
          > > > Dave,
          > > >
          > > > LLandstrom had a good idea by mixing some high silicon content
          > > alloy in with
          > > > his extruded scrap. The silicon gives it flowability which
          allows
          > > it to fill
          > > > the cavity quicker and to feed better. Might work for you too. I
          > > would use
          > > > 319 over 356 simply because 356 doesn't machine well unless it's
          > > heat
          > > > treated. 319, although dull, will machine pretty well in the as
          > > cast state.
          > > > They both will polish pretty well, better if both are heat
          treated.
          > > 535.2,
          > > > an aluminum/magnesium alloy is better. It takes a high polish
          and
          > > resists
          > > > corrosion which will keep the polished finish longer and,
          happily,
          > > Atlas
          > > > Metal Sales (http://www.atlasmetal.com/) carries it.
          > > >
          > > > Jim Clary
          > > >
          > > > ----- Original Message -----
          > > > From: <davehughes2002@y...>
          > > > To: <hobbicast@egroups.com>
          > > > Sent: Friday, December 29, 2000 12:34 PM
          > > > Subject: [hobbicast] extrusions
          > > >
          > > >
          > > > > Thanks for all your advice on the extrusion business. The
          visual
          > > > > results of the pour I described seemed not so much gaseous or
          > > > > containing inclusions, but microscopic paralell cracks(i'm
          > > assuming
          > > > > within the entire cast to its core after machining down quite
          > > deep to
          > > > > test), like some esoteric alloying defect i thought someone
          may
          > > have
          > > > > experienced. The charge was degassed, temp monitored, poured
          > > quickly
          > > > > etc. Bizarre, I hadnt seen anything similar in all my other
          > > scrappy
          > > > > pours. Regardless, i've been wanting to move up out of the
          hit and
          > > > > miss game into more consistant results and remove that crap
          scrap
          > > > > variable. I'll take your advice on staying with casting
          alloys
          > > for
          > > > > the higher end stuff.(I'll save those extrusions for that pot
          and
          > > pan
          > > > > set I was going to make for my mother in law.) I dont have
          much
          > > > > experience with 319 or 356 and was wondering which would be
          more
          > > > > suitable for decorative casting purpose only - good
          machinability,
          > > > > high buff, etc. If someone could relay their thoughts on
          general
          > > > > characteristics I may encounter between the two for this
          purpose,
          > > > > relative costs, and the like, I'd appreciate it. Thanks again
          > > guys. -
          > > > > dave.
          > > > > P.s. read a message back a few pages, someone asking for a
          plastic
          > > > > lettering source with good draft. Try MONTROSE COLORS in IL.
          > > 708-
          > > > > 588-7910. They acquired all of Decor-teq, inc.'s of CA. stock
          > > > > recently. They have several different fonts in injection-
          molded
          > > > > polypropylene I believe it is. Also a selection of artistic
          > > rosettes
          > > > > great for patterns. Hope this helps out.
          > > > >
          > > > >
          > > > > Please visit our sponsor: Budget Casting Supply
          > > > > http://budgetcastingsupply.com/
          > > > >
          > > > > The Home Foundrymen's Association website may be found here:
          > > > http://members.xoom.com/HWilkinson/index.htm
          > > > > It includes member project pages & links
          > > > >
          > > > > To unsubscribe from this group, send an email to:
          > > > > hobbicast-unsubscribe@egroups.com
          > > > >
          > > > >
          > > > >
          > > > >
          > >
          > >
          > > Please visit our sponsor: Budget Casting Supply
          > > http://budgetcastingsupply.com/
          > >
          > > The Home Foundrymen's Association website may be found here:
          > http://members.xoom.com/HWilkinson/index.htm
          > > It includes member project pages & links
          > >
          > > To unsubscribe from this group, send an email to:
          > > hobbicast-unsubscribe@egroups.com
          > >
          > >
          > >
          > >
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