Mold Making:

Procedure for Multiple Section Plugs

1. Split the plug in radius areas when it is practical to do so.
2. Cut walls as close to the surface of the plug as possible.
3. Wax the area under the wall.
4. Fill the bottom of the wall with a patching paste. Position it back over the plug, and allow it to cure.
5. Clean the excess patching paste off the plug surface.
6. Save this wall for the lamination process.
7. Use aligning pins or dowels so both sections will join together perfectly.

We have determined where we are to split the mold and have constructed a wall that fits exactly to the area of the plug. Now we are now ready to laminate this section only. We will then remove the wall and laminate the other section up to and including this wall which will give us two mold sections, married together, at the walls. We can then bolt or clamp these walls during the manufacture of the parts.

Fillers such as modeling clay, body putty or filled polyester and micro balloons are used for shaping and forming radii areas and design lines. Fillers should lend themselves to being sanded and filed easily. This will make the rough forming and finishing of the radii easier.

Drags constructed of plexiglass or wood and shaped into the size and dimensions needed are excellent ways to form both inside and outside radii. Design lines or multiple radii can be formed in this same manner. Some manufacturers specialize in making intricate drags and radius finders.

Finishing the plug is commonly the most important and the most difficult task of the builder. Fortunately, some new products on the market allow a paint-style finish with polyesters. These products are high-build systems, which can be applied in 15-20 mills with one application, using several passes.

Caution must be taken when applying these types of materials. The specific instructions issued by each manufacturer should be followed closely, since this material is different from a polyester gel coat.