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Re: [hobbicast] Re: K bond

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  • giesser@aol.com
    I have used sand with an AFS GFN of 200. It requires substantially more binder and oil. Most of the time I use a sand with an AFS GFN of about 100. With this,
    Message 1 of 10 , May 31, 2006
      I have used sand with an AFS GFN of 200. It requires substantially more binder and oil. Most of the time I use a sand with an AFS GFN of about 100. With this, I can cast my own finger prints!

      Tom Cobett
      Cleveland, OH

      "In Pyro Veritas"

      -----Original Message-----
      From: paul_probus <paul_probus@...>
      To: hobbicast@yahoogroups.com
      Sent: Wed, 31 May 2006 16:40:31 -0000
      Subject: [hobbicast] Re: K bond


      Tom,

      In regard to your last paragraph, are you saying that using finer
      than 120 is not recommended? Just curious because I saw on a site
      posted a couple of days ago they offer Olivine sand in 180, would
      that not work when you want very detailed surface?

      Thanks,
      Paul

      --- In hobbicast@yahoogroups.com, giesser@... wrote:
      >
      > If you look at all of the organo-bentone manufacturer websites,
      they all recommend using a mixture of 90% Methanol and 10% Water as
      the catalyst for standard bentones. Propylene carbonate is also
      recommended, since it does not evaporate. Personally, I prefer using
      propylene carbonate for this reason.>
      > Some organo-bentones do not require a catalyst. However, they will
      gel to a higher degree if a catalyst is used.
      >
      > Bentone and bentonite are NOT the same thing. Standard kitty
      litter cannot be used instead of bentonite in molding sand. The self-
      clumping type of kitty litter could be used as a molding sand
      binder, with water. There is no kitty litter in the world that can
      ve used to make an oil bonded sand like K-BOND or PETROBOND.
      >
      > The visocsity of the amorphous polybutene (commercially sold as
      INDOPOL) is a very important property. I like to use something like
      L-80, L-100 or H-15. These are fairly viscous. I would say that they
      are about the same viscosity as SAE 70 or 90 motor oil. If you use a
      very thin or low viscosity INDOPOL, you will not have very good
      strength in the sand mix.
      >
      > And finally, just because the bag says Silica Sand, it does not
      mean that it will work well as foundry sand. It is VERY important
      that the sand be between 80 and 120 mesh. We would say that it has
      an AFS GFN of 80 to120. It is also important for the sand to have a
      broad screen distribution. That means that not all the sand grains
      are the same size, but, on the average, they are between 80 and 120
      mesh. ALSO, a round grain sand is better than a sub-angular sand,
      since it has less surface area. And, a sub-angular sand is better
      than an angular sand, for the same reason. If we assume that the
      binder is like paint, you need less of it when you have less surface
      area.
      >
      > Using the correct ingredients, you will always make a good batch
      of K-BOND or PETROBOND.
      >
      > Tom Cobett
      > Cleveland, Ohio
      >
      > "In Pyro Veritas"
      >






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      [Non-text portions of this message have been removed]
    • wtbaker69
      Tom, Thanks for the very good info in this post. The indopol I found in fact was a very thin product not nearly like 90 wt gear oil. It was an L-24. At this
      Message 2 of 10 , Jun 11 4:29 PM
        Tom,
        Thanks for the very good info in this post.

        The indopol I found in fact was a very thin product not nearly like 90
        wt gear oil. It was an L-24. At this point I will assume that is my
        primary problem based on your info and go back and try to find
        something heavier.

        I found some lab screens and screened my sand. I used two screens, an
        80 and a 120. I'd say that 75% passed through the 80 screen, 30%
        passed through the 120 screen which leaves roughly:
        25% on the 80 screen
        45% on the 120 screen
        30% in the "pan" or smaller than 120.

        I contacted the guy who sold me the sand. He said it was a round sand.

        Wes


        --- In hobbicast@yahoogroups.com, giesser@... wrote:
        >
        > If you look at all of the organo-bentone manufacturer websites, they
        all recommend using a mixture of 90% Methanol and 10% Water as the
        catalyst for standard bentones. Propylene carbonate is also
        recommended, since it does not evaporate. Personally, I prefer using
        propylene carbonate for this reason.
        >
        > Some organo-bentones do not require a catalyst. However, they will
        gel to a higher degree if a catalyst is used.
        >
        > Bentone and bentonite are NOT the same thing. Standard kitty litter
        cannot be used instead of bentonite in molding sand. The self-clumping
        type of kitty litter could be used as a molding sand binder, with
        water. There is no kitty litter in the world that can ve used to make
        an oil bonded sand like K-BOND or PETROBOND.
        >
        > The visocsity of the amorphous polybutene (commercially sold as
        INDOPOL) is a very important property. I like to use something like
        L-80, L-100 or H-15. These are fairly viscous. I would say that they
        are about the same viscosity as SAE 70 or 90 motor oil. If you use a
        very thin or low viscosity INDOPOL, you will not have very good
        strength in the sand mix.
        >
        > And finally, just because the bag says Silica Sand, it does not mean
        that it will work well as foundry sand. It is VERY important that the
        sand be between 80 and 120 mesh. We would say that it has an AFS GFN
        of 80 to120. It is also important for the sand to have a broad screen
        distribution. That means that not all the sand grains are the same
        size, but, on the average, they are between 80 and 120 mesh. ALSO, a
        round grain sand is better than a sub-angular sand, since it has less
        surface area. And, a sub-angular sand is better than an angular sand,
        for the same reason. If we assume that the binder is like paint, you
        need less of it when you have less surface area.
        >
        > Using the correct ingredients, you will always make a good batch of
        K-BOND or PETROBOND.
        >
        > Tom Cobett
        > Cleveland, Ohio
        >
        > "In Pyro Veritas"
        >
        > -----Original Message-----
        > From: wtbaker69 <wtbaker69@...>
        > To: hobbicast@yahoogroups.com
        > Sent: Tue, 30 May 2006 23:26:25 -0000
        > Subject: [hobbicast] Re: K bond
        >
        >
        > I've tried the K-Bond sand recipes and followed them as closely as
        > possible but the results yield a loose mass of sand with far too
        > little green strength to make moulds for casting. (I did substitute
        > isopropyl alcohol for the methanol in one one batch and denatured
        > alcohol in the other two.)
        >
        > Wes
        >
        >
        > --- In hobbicast@yahoogroups.com, giesser@ wrote:
        > >
        > > This thread has gotten so old that I can't remember what the
        > original problem was.
        > >
        > > If someone could re-state the problem, I would be happy to post a
        > solution.
        > >
        > > Tom Cobett
        > > Cleveland, OH
        > >
        > > "In Pyro Veritas"
        > >
        > > -----Original Message-----
        > > From: Lyle <creepinogie@>
        > > To: hobbicast@yahoogroups.com
        > > Sent: Tue, 30 May 2006 15:43:35 -0000
        > > Subject: [hobbicast] Re: K bond
        > >
        > >
        > > I'm not a K-bond guy but I make petrobond all the time. I never add
        > > water. In fact, the sand has to be as dry as you can find it.
        > > Otherwise you don't get a good coating over the sand particles. It's
        > > really visible what the problem is when you have water in your sand.
        > >
        > > Regarding the mixing. You may want to add the catalist first to the
        > > sand (alchohol) and let the muller spin for a few minutes before
        > > adding the oil. Maybe your sand has too much moisture in it initially?
        > > LL
        > >
        > >
        > > > Wes:
        > > >
        > > > I remember clearly that I have read somewhere, sometime that it is
        > > important to add between 5% to 10% water to your alcohol catalist in
        > > order to get it to work properly. I must however warn you that I have
        > > never used oil bonded sand myself. This is purely something that I
        > > recall from memory. Maybe some types of Bentone require that you add
        > > water to the catalyst? Anyhow, it might be worth a try since you have
        > > nothing to loose. Let us know.
        > > >
        > > > Regards,
        > > > Deon.
        > > >
        > > >
        > > >
        > > >
        > > > <The sack said "Bentone" in big letters. Underneath that, it said
        > > > <"realogical gel". I may be misspelling the "realogical" word, it
        > > > <could have been rhealogical. I bought 25# and transferred it from
        > > the
        > > > < large bag into a bucket myself.
        > > >
        > > > <The batch I worked up with the 2-cycle oil has similar properties,
        > > > <just almost no green strength. If you pack a fist full of it
        > > tightly
        > > > <and open your hand carefully, it will hold it's shape. If you even
        > > > <touch it though, it breaks in pieces.
        > > >
        > > > <Do you think some other type of clay was in the bag? This stuff is
        > > > <real light and looks very similar to bentonite to me. How can I
        > > tell
        > > > <if it is really "bentone"?
        > > >
        > > > <Wes
        > > >
        > >
        > >
        > >
        > >
        > >
        > >
        > > 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
        > >
        > >
        > >
        > >
        > >
        > >
        > > [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
        >
        >
        >
        >
        >
        >
        > [Non-text portions of this message have been removed]
        >
      • Lyle
        What is round sand? No fractured faces or angularity??? LL ... It s ... initially? ... it is ... catalist in ... have ... add ... have ... from ...
        Message 3 of 10 , Jun 11 8:56 PM
          What is "round" sand? No fractured faces or angularity???
          LL

          --- In hobbicast@yahoogroups.com, "wtbaker69" <wtbaker69@...> wrote:
          >
          > Tom,
          > Thanks for the very good info in this post.
          >
          > The indopol I found in fact was a very thin product not nearly like 90
          > wt gear oil. It was an L-24. At this point I will assume that is my
          > primary problem based on your info and go back and try to find
          > something heavier.
          >
          > I found some lab screens and screened my sand. I used two screens, an
          > 80 and a 120. I'd say that 75% passed through the 80 screen, 30%
          > passed through the 120 screen which leaves roughly:
          > 25% on the 80 screen
          > 45% on the 120 screen
          > 30% in the "pan" or smaller than 120.
          >
          > I contacted the guy who sold me the sand. He said it was a round sand.
          >
          > Wes
          >
          >
          > --- In hobbicast@yahoogroups.com, giesser@ wrote:
          > >
          > > If you look at all of the organo-bentone manufacturer websites, they
          > all recommend using a mixture of 90% Methanol and 10% Water as the
          > catalyst for standard bentones. Propylene carbonate is also
          > recommended, since it does not evaporate. Personally, I prefer using
          > propylene carbonate for this reason.
          > >
          > > Some organo-bentones do not require a catalyst. However, they will
          > gel to a higher degree if a catalyst is used.
          > >
          > > Bentone and bentonite are NOT the same thing. Standard kitty litter
          > cannot be used instead of bentonite in molding sand. The self-clumping
          > type of kitty litter could be used as a molding sand binder, with
          > water. There is no kitty litter in the world that can ve used to make
          > an oil bonded sand like K-BOND or PETROBOND.
          > >
          > > The visocsity of the amorphous polybutene (commercially sold as
          > INDOPOL) is a very important property. I like to use something like
          > L-80, L-100 or H-15. These are fairly viscous. I would say that they
          > are about the same viscosity as SAE 70 or 90 motor oil. If you use a
          > very thin or low viscosity INDOPOL, you will not have very good
          > strength in the sand mix.
          > >
          > > And finally, just because the bag says Silica Sand, it does not mean
          > that it will work well as foundry sand. It is VERY important that the
          > sand be between 80 and 120 mesh. We would say that it has an AFS GFN
          > of 80 to120. It is also important for the sand to have a broad screen
          > distribution. That means that not all the sand grains are the same
          > size, but, on the average, they are between 80 and 120 mesh. ALSO, a
          > round grain sand is better than a sub-angular sand, since it has less
          > surface area. And, a sub-angular sand is better than an angular sand,
          > for the same reason. If we assume that the binder is like paint, you
          > need less of it when you have less surface area.
          > >
          > > Using the correct ingredients, you will always make a good batch of
          > K-BOND or PETROBOND.
          > >
          > > Tom Cobett
          > > Cleveland, Ohio
          > >
          > > "In Pyro Veritas"
          > >
          > > -----Original Message-----
          > > From: wtbaker69 <wtbaker69@>
          > > To: hobbicast@yahoogroups.com
          > > Sent: Tue, 30 May 2006 23:26:25 -0000
          > > Subject: [hobbicast] Re: K bond
          > >
          > >
          > > I've tried the K-Bond sand recipes and followed them as closely as
          > > possible but the results yield a loose mass of sand with far too
          > > little green strength to make moulds for casting. (I did substitute
          > > isopropyl alcohol for the methanol in one one batch and denatured
          > > alcohol in the other two.)
          > >
          > > Wes
          > >
          > >
          > > --- In hobbicast@yahoogroups.com, giesser@ wrote:
          > > >
          > > > This thread has gotten so old that I can't remember what the
          > > original problem was.
          > > >
          > > > If someone could re-state the problem, I would be happy to post a
          > > solution.
          > > >
          > > > Tom Cobett
          > > > Cleveland, OH
          > > >
          > > > "In Pyro Veritas"
          > > >
          > > > -----Original Message-----
          > > > From: Lyle <creepinogie@>
          > > > To: hobbicast@yahoogroups.com
          > > > Sent: Tue, 30 May 2006 15:43:35 -0000
          > > > Subject: [hobbicast] Re: K bond
          > > >
          > > >
          > > > I'm not a K-bond guy but I make petrobond all the time. I never add
          > > > water. In fact, the sand has to be as dry as you can find it.
          > > > Otherwise you don't get a good coating over the sand particles.
          It's
          > > > really visible what the problem is when you have water in your sand.
          > > >
          > > > Regarding the mixing. You may want to add the catalist first to the
          > > > sand (alchohol) and let the muller spin for a few minutes before
          > > > adding the oil. Maybe your sand has too much moisture in it
          initially?
          > > > LL
          > > >
          > > >
          > > > > Wes:
          > > > >
          > > > > I remember clearly that I have read somewhere, sometime that
          it is
          > > > important to add between 5% to 10% water to your alcohol
          catalist in
          > > > order to get it to work properly. I must however warn you that I
          have
          > > > never used oil bonded sand myself. This is purely something that I
          > > > recall from memory. Maybe some types of Bentone require that you
          add
          > > > water to the catalyst? Anyhow, it might be worth a try since you
          have
          > > > nothing to loose. Let us know.
          > > > >
          > > > > Regards,
          > > > > Deon.
          > > > >
          > > > >
          > > > >
          > > > >
          > > > > <The sack said "Bentone" in big letters. Underneath that, it said
          > > > > <"realogical gel". I may be misspelling the "realogical" word, it
          > > > > <could have been rhealogical. I bought 25# and transferred it
          from
          > > > the
          > > > > < large bag into a bucket myself.
          > > > >
          > > > > <The batch I worked up with the 2-cycle oil has similar
          properties,
          > > > > <just almost no green strength. If you pack a fist full of it
          > > > tightly
          > > > > <and open your hand carefully, it will hold it's shape. If
          you even
          > > > > <touch it though, it breaks in pieces.
          > > > >
          > > > > <Do you think some other type of clay was in the bag? This
          stuff is
          > > > > <real light and looks very similar to bentonite to me. How can I
          > > > tell
          > > > > <if it is really "bentone"?
          > > > >
          > > > > <Wes
          > > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > > 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
          > > >
          > > >
          > > >
          > > >
          > > >
          > > >
          > > > [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
          > >
          > >
          > >
          > >
          > >
          > >
          > > [Non-text portions of this message have been removed]
          > >
          >
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