- Casting Resin Freight Cars
||Build the Master
styrene or strip wood, build the master component pieces
including sides, ends, floor and roof. If using wood, be sure to seal
the master with a coat of Testor’s Gloss Coat and sand lightly.
||Make a Rubber Mold
the masters to a piece of foam-core board using rubber cement.
Be sure there are no severe undercuts of anywhere the rubber
can get underneath the masters as it will trap the master in the
rubber and both will be destroyed. After allowing 15 minutes to
dry, build a box around the masters with strips of foam-core approximately
½ inch taller than the masters. Use strips of duct tape
to fasten the strips to the bottom box to the
Mix RTV rubber in
accordance with the product directions. Pour the rubber over the
masters until the box is full. Place the box on a surface that will
vibrate such as an electric sander ( I use and old Foot-fixer foot
bath.) Vibrate for 10 minutes or until bubbles no longer come to
the surface. Allow the rubber to cure to 24 hours. Some products
say they cure in 4 hours – I have not had success trying to use
after such a short time, 24 hours is best. After the mold has fully cured,
remove the duct tape and foam-core strips. Remove
the mold from the foam core base.
||Pouring the Casting Resin
|| Mix the resin in accordance with the product instructions
and pour into the mold. Only mix small quantities at a time (about ¼ to
½ oz. of each part. It is OK to pour a new batch of resin on top of the
previous batch, it will bond just fine. Use a toothpick or a piece of
small wire to work the resin down into small detail cavities in the mold.
Working from one side to the other, lay a piece of waxed paper over the
resin making sure not to trap air bubbles in the casting. Allow the resin
to cure at least 10 minutes before attempting to remove the parts from the
mold. When the parts have been removed, assemble the car using ACC or
other type of super glue. Add additional details and decals as you desire.
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