Friday, July 16, 2010

Molding Broken Parts. Fixing the parts you can't find anywhere else.

Using ComposiMold Reusable Mold Making Materials is a useful way to make parts that you can't get anywhere else. Make new parts from old broken parts simply by molding them.

Here is a useful example of fixing a part that we could not find anywhere else-or at least not at a reasonable price. This is a cap to a bilge pump that goes on to a sailboat.We would have had to purchase this cover plus the internal pump that went along with it. This was much too expensive and unnecessary.

So being the clever, do it yourself types that we like to think we are, we molded and cast the part with ComposiMold mold making material and ComposiCast urethane resin.

The original broken piece was glued together.  Small pieces that were missing were filled and shaped with polymer clay.

Then we made the mold.  The ComposiMold was melted and poured into a container large enough to hold the cover. The part was placed on top of the ComposiMold and pressed in slightly. This half of the mold was allowed to solidify and hold the part in place.

The second half of the mold was poured over the cover to completely cover it up. This was allowed to cool.

After the ComposiMold mold solidified, it was cut open with a knife. The original part was removed. It actually came apart at this point. The glue was not strong enough.

A small hole was cut into the ComposiMold to allow the urethane casting resin to be poured into the mold cavity.  The two mold halves were placed between heavy pieces of cardboard and taped together.

The mold was sprayed with a mold release and ComposiCast was poured into the cavity. After the plastic casting cured it was removed from the mold. Edges were trimmed with a razor blade. The  part needed to be sanded a little.

We now had a new plastic cover. Much nicer.

For more information on the reusable mold making material visit
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1 comment:

  1. That is so brilliant. What a great idea. Thank you for writing about this. Have a great day!


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