The Repro Laminating System

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Repro Surface Coat and Laminating Resins are a popular choice among our customers who are making a medium-sized tool and don’t need the strength of an epoxy.

To demonstrate working with a Repro surface coat and laminating resin system, we will create a tool based on this part. The frame is made of pine wood and the entire part has been treated with one coat of Freeman Wax Release and one coat of PVA mold release. For proper application procedure, please refer to our other video on this subject.

Our Repro Surface Coat and Laminating Resin system has several advantage over using an epoxy, such as the easy 1 to 1 mix ratio, the lower cost, and the shorter gel times allow an entire tool to be created in 75 minutes, as opposed to overnight. Also, by using fiberglass strand instead of cloth, it is easier to fit the tool around intricate parts.

Applying Repro Surface Coat

Repro Surface Coat starts out thinner than an epoxy, so we want to start out by covering the areas of our part with the highest detail and the corners.

If the viscosity was too thin, such as for applying material on vertical walls, we would wait a bit and it will thicken up.

We will be applying two layers of surface coat, so we’re not as worried about getting everything the first time around.

We’re not worried about excessive build-up (as in epoxy) because Repro doesn’t produce a lot of heat.

After three minutes, notice how the liquid is already thickening up, making it easier to apply to vertical surfaces.

The gel time is determined by what point the material is so thick that it will no longer self-level.

The almost tack-free state will occur in about 15-20 minutes, and then we are ready for the second coat.

Again, we started on the areas requiring the highest detail. We can also apply this layer more liberally.

Apply Laminating Resin and Fiberglass Strand

With our surface coat again at an almost tack-free state, we’re mixing up a small amount of our laminating resin. Then we apply one coat directly on top of the surface coat to act as an adhesion layer.

Next, we’re ready to mix the
laminating resin with the fiberglass strand. First, we mix the two sides of the laminating resin like any other 1:1 ratio liquid tooling material. Then we pour the mixture into a larger cup and begin adding the chopped fiber.

We can make this as wet or dry as we like. The drier you make it, the lower the resin content, which will lessen both the heat and the shrinkage. However, we’ll want make sure these enough resin so it is still sticky.

Here we have our finished “dough-like” material. The top of our tool is still wet from our adhesion layer as we begin to apply it everywhere. We work it into the smaller areas with a paint paddle.

There will be more material used here than with an epoxy layup, so we can expect a little more shrink, but it is will more controllable and uses a lot less material than a mass cast – which is why mass cast parts are usually used only for smaller parts.

As we progress, it may be difficult to see exactly how thick our tool is. We want 1/4 to 3/16 of an inch. Notice how much easier it is to apply this thick of material than it is if we were using numerous layers of fiberglass cloth – this is one of the primary advantages of Repro Surface Coat and Laminating Resin.

As our mixture starts to dry, it is even easier to work with. We can even form it with our hand.


Here we are unscrewing the backside of our mold. Then, after turning the mold back over, we gently tap four wedges to begin separating our tool. It is important to lift the tool evenly. If you lift from an angle, we may create a negative draft, which we don’t want.

Once the tool is removed, we have to remove the PVA mold release by dampening a cloth and wiping off the entire surface of our tool.