Casting hardbaits with PU (polyurethane), for the best lure replicas!

Casting a jerkbait / crankbait or hardbaits from plastic is becoming increasingly popular. Many builders take their first steps on the self-build path, often with wood and then switch to plastic. The reason is that wooden baits always differ in detail from each other. There is often not 1 the same. This may have to do with a different structure in the wood used, but more often this is due to the builder himself. Sawing is still manual work and a millimeter difference is easily made. Of coursed has this too charm, but if you want to work more serially, plastic is miles ahead of wood. This blog is about how you can easily make copy after copy of a home-made jerkbait / crankbait. Casting hardbaits with PU (polyurethane)

Make a copy of this

The beginning…

We have started rolling out a piece plasticine. Plasticine is a clay-like mass that can be used several times. It does not air dry and cannot be put in the oven. But this material is a solution for making a 3D mold!

The first step is to place the bait on the sheet of plasticine and stretch it with a teaspoon. This creates the contour of the bait. You now need to spoon this out so that the bait sinks into it, as it were. Now allow the bait to collapse by half and press the edges firmly so that no silicone can leak through. Now finally make a pouring opening and 6 to 10 cavities. I make the cavities with the back of a 10 mm drill. This way you can neatly put the two mold halves back together before the casting process.

Casting hardbaits: making mold halves

The first half of the mold

Then I build a box of Lego around it and make the RTV Silicone On. This is a silicone that has been specially developed for working with Polyurethane (PU); the plastic that we will use for casting the final bait. Mixing ratio of the silicone is by weight (5%)

The amount of silicone you need to make is easy to calculate by calculating the length x width x height of the container. The cubic cm resulting from this equals the number of milliliters. I also sealed the sides of the Lego container with Plasticine. This is to prevent leaks. I now leave the mold for 24 hours to harden.

Turn the mold over and premove lasticin...

Now we turn the mold over and remove the Plasticine. The result is the first half of our casting mold. Now we repeat the whole process. What is important now is to spray the first half well with a spray gun before you start making the second half of the mold. release agent. This prevents the parts from getting stuck together. Now we rebuild the box of Lego and make the other half of the mold.

The second mold half

Mold ready to use

The casting process

After we have allowed the second half to harden for another 24 hours, we can start casting the replicas. We are going to cast the replicas with Polyurethane. This PU has a demoulding time of 30 minutes and a processing time of 6 minutes. You can also use a maximum of 25% glass beads add to the PU. These glass beads provide more buoyancy to the end product. In the case of a jerkbait, for example, this is of course very important.

The Replica.

As you can see, casting hardbaits is not difficult. As with many things, practice makes perfect. It is also possible to cast a plug (crankbait) or a streamer head. You can also copy shads with this method. Then you don't use PU for the end product Plastisol

If you want to know more about this, I can help you this Blog to recommend wholeheartedly!

— > NB : After reading this article, do you want to get started yourself? Then check it out this beautiful package at sometime.

Finally, some photos we received from customers…

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Thanks to Rick Barten :)