Video
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The creator shows the components and tools necessary for casting a fishing lure.
The resin he is using is a urethane resin. It cures very quickly. He notes that once you mix the resin and catalyst, you have only 2.5 minutes of working time before it sets up.
Along with resin, the casting mix includes microspheres to add bouncy. Partially to control whether the lure is a floater or a sinker, but also to bias the lure so the top of the lure stays on top.
The creator notes that he uses a brush to mix the resin because it does a more thorough job, especially in the bottom edge of the mixing cup. This is a very interesting technique that makes a lot of sense.
Another interesting technique the creator notes is to use a pair of wooden blocks on either side of the silicone mold to prevent the mold from twisting and deforming the cast part. Any uneven loading of the rubber bands holding the two mold halves together could cause this, so this is another great technique that this creator is presenting.
To estimate the amount of resin needed to fill his casting, he displaces some water with the lure that he used to make the mold. The displaced water is weighed to then calculate the volume of the mold. Yet another great technique presented by the creator.
Once he's computed the total volume of resin to mix, he then calculates the amount of part a and part b (in grams) to measure into his mix. The calculations are a bit tedious and it would certainly be much easier to just use epoxyportal's project manager to compute all of this directly.
The creator measures the resin parts, then the microspheres, mixes in the microspheres and then mixes the two parts together. He stirs them together to get a good mix, pours the solution into the mold and taps the mold to help air bubbles escape.
At the end, the creator notes that the flashing around the edges can be sanded down once the resin fully cures. He also notes that before painting, the molded part should be cleaned with rubbing alcohol to ensure the paint adheres properly.
This is an outstanding tutorial and I highly recommend watching the video.