Without wasting much material, lay out the six hull pieces on cardboard.
Cut out each part carefully with scissors.
This is how each part should be oriented for assembly.
Masking tape can be used to temporarily hold the parts together. However, you will need to use reinforced hot melt adhesive between strips of masking tape.
Here you can see how hot melt adhesive should be used instead of masking tape. This glue joint should be reinforced with a scrap of glass cloth.
Work slowly down the length of each seam. You must allow the hot melt adhesive to cool as you go. It would be a good idea to reinforce the joint occasionally with glass cloth.
Joints can be reinforced by embeding scraps of glass cloth in the adhesive while it is still hot. Use a popsicle stick to push the reinforcement into the adhesive. The joint does not need to look pretty on the outside, but it should be clean and tight on the inside.
Work carefully to align all edges. The inside of the mold cavity should be neat and clean with uniform joints.
Here is a hull that has been assembled with hot melt adhesive. Only areas of high strain need glass reinforcing.
It is best to work with a partner to assemble the mold. One person can hold the joints tight while the other adds the hot melt adhesive and reinforcing cloth. The glue joints must be held until the adhesive is completely cool.
Stretch the glass reinfocement tightly over joints.
When the hull is assembled, check that all of the inside joints are tight and uniform.
The mold will need several uniform coats of paste wax.
The wax will seal the porus cardboard and act as a mold release so the polyester resin won't stick to the cardboard. Allow the wax to dry between coats.
Here we see a mold made of heavy paper but this step is the same for a cardboard mold. When the paste wax is dry, you need to coat the inside of the mold with PVA.
Apply a coat of PVA with a brush. Apply a uniform, thin coat. Not so much that the PVA liquid runs into the bottom of the mold.
Tilt the mold up to get rid of any excess PVA.
Excess pva can be dumped back into the container.
When the PVA is completely dry, APPLY A SECOND COAT!
The PVA will dry faster with a lot of air circulating over the mold.
While the second coat of PVA is drying, you can cut out the reinforcement materials.
Without wasting material, layout the mold patterns on 3/4 ounce veil.
The glass veil can be cut with scissors, a sharp knife, or a rotary cutter.
You will also need to layout and cut each mold pattern from 6 ounce glass strand mat. This can also be cut with a knife if you cut on a waste board.
You will also need a piece of 4 ounce glass cloth that is slightly longer and wider than the hull mold.
Use the pattern for the bottom of the mold to locate two slits. You should slice in from each end using scissors.
When the cloth is ready, you can begin mixing resin.
It is often helpful to fasten the mold to the center of a newspaper.
Mix up a small amount (1 ounce) of resin with colorant and thickener. This first coat of resin acts as the gel coat so apply it to the inside of the mold without trapping any air bubbles on the surface of the mold.
After the gel coat begins to set up, carefully set all of the veil in place.