Jun 15

Last summer a buddy of mine asked me if I could make him a duplicate license plate for his vintage truck.  The original California plate that he had was black with yellow lettering and he wanted to keep that plate.  Apparently you can’t purchase duplicate California plates so his only option was to make a copy.

Even though I have never attempted a project like this one I jumped at the opportunity.  The concepts of the making of a fiberglass mold don’t change so I knew that if I followed the standard protocol that it would work out fine.

This project went smoothly – just like planned.  The old plate was stripped of its registration tags and it was straightened out as good as possible.  It was then mounted to a parting plane with wood screws and the edges were sealed with clay.  The plate was then waxed heavily with mold release wax and then it was sprayed twice with PVA and set aside to dry.

When the time came to build the mold itself I started getting nervous.  While I have only once before had a plug ruined by a combination of failed release agents and tooling gel coat that failed to cure, I really didn’t want this to happen to  my buddies license plate.  That being said I did what I always do and pushed forward.

After a liberal application of tooling gel coat followed by fiberglass resin and a few layers of 1 ½ oz mat my mold was complete.  I was thrilled when I de-molded a few days later and found a perfect mold and even better – an un-marred original plate.  Whew!

With my new mold I went ahead and prepared it with mold release wax and PVA and proceeded to follow all the steps to make a part with this mold (all of these steps are covered in my series of fiberglass mold manuals).  Just like with the making of the mold, making this part went just as planned and I ended up with a near perfect duplicate of my buddy’s license plate.  The mold however did not do so well.  After pulling the part from the mold a host of flaws were revealed in the mold – most of them were air pockets / voids in the tooling gel coat.  The flaws in the mold were significant enough to make the mold not suitable for further use.

After this experience I decided to try this project again – only this time I would use silicone rubber for making the mold and simply make parts by laying gel coat, fiberglass resin and mat into the silicone mold.  There are several benefits to this process for this particular mold as compared to making a fiberglass mold.  More on this project in the next post!

Happy Glassing

Steve

www.fiberglassmoldmanual.com