From: Jim Pike (jim.pike@gmail.com)
Date: Wed May 30 2007 - 17:16:11 EEST
As another suggestion, you can use a wax with high plastic content. Check
with your local supplier.
The higher pastic content will enable extended wear resistance.
Of course that depends on your expectations and the number of molds you
need??
A good "release" coating before ramming with sand will be imperative.
Jim
On 5/29/07, Brett Lyons <lyonsb@umich.edu> wrote:
>
>
> Hi,
>
> If cost is a very important issue, you can get results comparable to an
> epoxy infiltrated tool with a low-exotherm MEKP catalyzed polyester or
> vynil ester infiltration. Keep your catalyst to resin ratio <=1:50, and
> the shell coating very thin because kick-off can distort a part if the
> reaction temp gets near 90C. That would be about ~1/2 the cost of
> epoxy, and still give you the stiffness required for properly ramming
> up a mold and allow you to give a good finish to the tool. As for ease
> of use... isn't running the melt, mounting the tool and molding
> exponentially more of a hassle than pattern infiltration?
>
>
> Cheers
> -Brett
>
>
>
>
> Brett Lyons
> Senior Research Technician, UM3D Lab
> Graduate Student, Mechanical Engineering
> FSAE, SAE, SME, AFS
> 734-647-5497
>
>
>
> Quoting "Petar O." <intrio@gmail.com>:
>
> > Dear colleagues,
> >
> > I've been using powder models infiltrated with wax (yes, just plane and
> > normal wax) for sand casting. My results are good but, as you can
> imagine,
> > my parts don't last long.
> >
> > I know wax isn't the toughest infiltration material but I have my
> reasons to
> > do so:
> > 1. cheap
> > 2. fast - you can deep the part
> > 3. reusable - just reheat it and it's ready to go.
> >
> > I don't want to use epoxy because you have to use certain amount so you
> > won't waste material unnecessary. CA is too expensive.
> > I've heard that some wood preservative would work fine with the powder
> but I
> > haven't tried it.
> >
> > Do you know some material that would have the same characteristics that
> the
> > ones stated above?
> >
> > Thanks and...keep building layers!
> > P.-
> >
>
>
>
>
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