Mold release (also known as a parting agent) is an essential step when making a mold. It is very important to take the extra time to add it to your mold or plug. It will add several hours to a project but is well worth it. It is used to allow a part to be easily removed from the original plug or the mold. Plus, it adds a durable surface finish to the part and keeps both the part and the mold from being damaged during production.
The two most well-known mold releases used are: Partall Paste #2 (wax) and Partall #10 (PVA). When both these mold releases are used together, it forms a great release system.
Partall paste #2 (or other brand wax) can be used on the mold first. It is important to rub it on evenly. It will need to dry between layers but be careful not to let it dry too long or it will be more difficult to wax off. The wax can be applied as you would when waxing a car. It is recommended to use several layers.
Next you can use PARTALL Film #10 or other PVA release film (such as Fiberlease). PVA is a polyvinyl alcohol solution of water-soluble, film forming material. It is used as a parting agent for separation between polyester or epoxy resins and various mold surfaces. PVA can be brushed on but it is recommended to use a spray gun when applying it.
At least three layers of PVA should be applied but more can be used if desired. The first layer should be a thin mist with the following layers being heavier. The PVA should dry completely between each layer.
PVA will not shrink or pull away from corners or curved surfaces. The film parts easily and cleanly from the mold surface. It is easy to clean off afterwards. Rinsing or spraying the part, mold or spray equipment will dissolve the PVA. The PVA leaves a tack free, durable surface.
PVA is not recommended for use with resins containing water, or giving off water during cure (ex. phenolics), or with automotive finishes as damage may occur. PARTALL Paste #2 or wax is suggested for most mold surfaces prior to application of PVA.
Partall #2 and PVA are not the only mold releases available on the market. Another mold release that we carry is called Orca Shimmer Wax. Orca Shimmer is a highly effective carnauba-based paste wax designed for the fiberglass molder. It is a high value mold release that yields a durable film. This film is resistant to abrasion. It is recommended that you use three to five coats of Orca Shimmer on clean or new molds. It should be applied one small section at a time (approx. 9 square feet or one square meter) until the entire mold surface is covered. Next, allow the wax to form a haze on the surface. The surface should be wiped with a clean cloth to remove excess wax. Lastly, it should be buffed to a high luster. After the initial application, single coats should suffice. The Orca Shimmer wax will continue to give a good release and high surface luster. In high humidity, it may be necessary to give the mold a final wiping with a clean, dry cloth to remove any haze that develops from unreleased solvents. A clean cloth should always be used when applying and buffing this product to avoid any contamination.