Fiberglass Layup

All the materials and tools needed for a fiberglass layup are readily available at your friendly local WalMart.  Get:

      1. Fiberglass resin and fiberglass cloth and a can of car wax in the automotive department

      2. A couple of 2 inch chip brushes and a quart of acetone in the paint department

First, give the mold a couple coats of wax.  Car wax is not the very best mold release available, but it works fine and it's cheap.  Photo 1

Next, rough cut two pieces of glass cloth at least 1/2 inch larger all around than necessary to fill the mold cavity.  Use cheap sissors to cut the cloth.  Mix about 1/8 of a quart of resin with about 1/8 of the small tube of catalyst that comes with the resin.  While it's not necessay to be terribly accurate in your mixing ratio, it's a good idea to use a ruler and felt tip marker to number depth marks on the side of the resin can and the catalyst tube.  I found that roughly 1 inch out of the resin can needed about 1/4 inch out of the catalyst for a nice mix.  Photo 2.

Once the resin is mixed you have only 10 or 15 minutes (depending on temperature) to finish the layup, so from this point move quickly and smoothly.  Coat the inside of the mold cavity and about 1/2 inch around the outside with a thick layer of resin.  Some people just pour in some resin and then smear it around with the brush.  Photo 3.

Then stuff the first piece of pre-cut glass cloth into the wet mold.  Use the brush to push the cloth down into the resin, brush on more resin to completely wet out the cloth.  Areas that are not wet out will appear white.  Photo 4.

Put the second piece of glass cloth into the mold and wet it out like you did the first piece.  Then, using the brush in a stabbing, stippling motion to poke the resin into the cloth weave.  The idea is to get all the air bubbles out of cloth and get the cloth down snug against the mold surface.  Air bubbles will appear lighter than the rest of the layup.  Pay special attention to cornors and curved areas.  Photo 5. Keep working the layup until the resin starts to set up.  When the resin starts to set it will first get a jelly like texture, stop stippling at that point and throw away the brush. If you got any resin on your hands, a little acetone will clean it off. 

Let the layup cure for several hours or overnight, then use a putty knife to pry around the outside of the molding until the part pops loose from the mold.  Photo 6.

A bandsaw works great to trim the excess glass from the outside of the part.  Some folks use old tin snips or even sissors.  Photo 7.  Finally, finish with sandpaper, clean the surface with acetone and paint.

Link to Yoke Centerpiece,  Fiberglass Mold

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