From: Brett Lyons (lyonsb@umich.edu)
Date: Wed May 30 2007 - 04:36:15 EEST
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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