Removing a Fiberglass Part From it’s Mold

A little more here regarding removing your fiberglass part from your mold.

If you waxed your mold well and applied a good coat or two of  PVA, your part should easily pop out of the mold.

The operative word in the ^^ Sentence Above ^^ is “SHOULD”!  For a better understanding of why it may not “Easily” pop out of the mold, read my previous post:

I like to use wooden coffee stirrers, tongue depressors and plastic putty knives to accomplish the removal of my part.

Be advised, there are specific tools designed for this work.  Wedges of all different types are available; some can even be used to inject air between the part and the mold itself.

Begin by pushing one stick or wedge between your part and the mold.  Don’t force it all the way under.  You are just starting the process.

The first stick will cause slight separation.  Insert a second  stick near the outer edge of the separation caused by the first stick.  Insert this stick as deep as possible without forcing it or risking fracture of your part.  This second stick will expand the area of separation between the mold and your part.

Continue the process of inserting sticks between the mold and your part.  Work your way around the part in this same fashion.  Insert a stick wherever possible until your part lifts from the mold.

Once your part has been removed from the mold, the edges can be trimmed with a Dremel tool or with a sanding block.  Be careful, the edges will be sharp.

Inspect the surface of your part for flaws.  Any flaws can be addressed with bondo, glazing putty or a mixture of cabosil and resin.

Good glassing to you,


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