Products used in this How To:
Tail Light Casting w/o Equipment
are going to take a look at the process for casting clear lenses
without the use of equipment. This process will walk you through
each and every step.
first step to casting your tail light lense is to warm your mold
to help the resin cure properly in thinner sections. We recommend
15-30 minutes at 150 F or 1 minute/lb of rubber on high in a microwave.
This will make the molds warm to the touch but should not be so
warm that you can not hold onto them.
open up your Alumilite Water Clear kit.
equal amounts of A and B. Shown in this picture is an inexpensive
digital kitchen scale Alumilite sells that is perfect for measuring
silicone rubber and resin.
you measure out the A side, add a few small drops of dye to color
the resin. Here we will add a few extra drops or red to help differentiate
resin in the pictures.
best way to consistently color every casting is to add the dye
to the A side container. If you don't want to color all of your
Water Clear, count the drops you add to the A side and repeat this
same number for every cast piece you pour. The more dye you add,
the darker the color. What you see is what you will get so only
add as much as you would like to see in your finished part.
add the same amount of B side as you did the A side. This will
keep you on proper 1:1 mix ratio by weight.
your stir stick down to the bottom of the container and stir the
resin extremely slow for 2 minutes. This will drastically reduce
the amount of air bubbles you create as you mix seeing as though
we will not be using equipment to help us eliminate bubbles in
by pouring some of the resin down the side of the mold very slowly.
Fill the mold up approximately 1/2 way.
paint the remaining resin onto the male portion of the rubber mold.
This will reduce the surface tension from that half of the mold
and help the air bubbles migrate to the seam line and out of the
you've painted some resin on the male half of the mold, line up
the locators and on an angle, slowly lay the male half onto the
female. This will allow the air to be squished out the seam and
reduce the amount of air that will be trapped.
lay the top half on the bottom and do not push it down. Make sure
the locators and mold are in the proper place. Then walk away from
it. Let the mold sit for a minimum of 1 hour. If your part is thinner
than 1/8", it is recommended to post cure the part in an oven
at 150 F for 30-60 minutes to help the thin resin piece to cure
properly. Allow the mold to cool before demolding.
the resin has cured, separate the two halves of the rubber mold.
you can see the lense with flash around the part still sitting
in the female half of the mold.
is often times easier to remove the flash while the part is still
in the mold. Simply peel it away from the seam line and throw it
other option is to simply pull the part out of the mold and trim
it off with an Exacto knife.
you can see the original lense (left), along with the two piece
rubber mold (top), and the darker cast reproduction (right). As
you can see our cast replica is darker than the original. If you
wish to match an exact color, simply run small test batches to
figure out the exact amount of dye you need to match the color
you desire. Then cast your piece with that amount of dye added
to the Water Clear.