Making your own soft plastic fishing lures is straightforward once you understand the core process: heat liquid plastisol until it turns clear, pour or inject it into a mold, let it cool, and you have a finished bait. The whole cycle from liquid to lure takes just a few minutes per batch, and a basic setup costs less than a few bags of premium store-bought soft plastics. Here’s everything you need to get started.
What You Need to Get Started
The material at the heart of soft plastic lure making is plastisol, a liquid PVC system that transforms into flexible, rubbery plastic when heated and cooled. It comes in jugs or bottles and looks like a milky white liquid at room temperature. You can buy it from specialty suppliers like Bait Plastics, Do-It Molds, or Barlow’s Tackle in various formulas ranging from soft (for thin, finesse-style baits) to firm (for bulky swimbaits or jerkbaits).
Beyond the plastisol itself, you’ll need:
- A mold. Aluminum injection molds and open-pour silicone molds are the two main options. Aluminum molds produce cleaner, more detailed lures and work with an injector. Silicone molds are cheaper and let you create custom shapes by casting an existing lure.
- An injector. This is essentially a large syringe, usually aluminum, that you fill with heated plastisol and press into the mold’s sprue hole. Common sizes are 45 ml (1.5 oz) for small baits and 120 ml (4 oz) for larger ones. Dual injectors let you load two colors side by side for laminate patterns.
- A heat source. A microwave works for beginners. Pyrex measuring cups handle the heat well and make pouring easy. A dedicated hot pot or electric melting pot gives you more temperature control for consistent results.
- A thermometer. An infrared thermometer is ideal because you can check the temperature without dipping anything into the plastisol.
- Colorants, glitter, and scent. Liquid colorants designed for plastisol come in every shade imaginable. Glitter flake adds flash. Salt can be mixed in to add weight and texture. Scent oils formulated for plastisol (garlic, crawfish, anise) can be stirred in at the end.
Heating the Plastisol
Getting the temperature right is the single most important step. Plastisol transitions from its milky, opaque state to a clear, pourable liquid between 300 and 320°F (149–160°C). For most injection work, you want a working temperature of 320 to 350°F (160–177°C). Too cool and the plastic won’t fill the mold completely. Too hot and it can scorch, turning yellow or brown and releasing heavier fumes.
If you’re using a microwave, heat in short bursts of 30 to 60 seconds, stirring gently between each round, until the plastisol goes fully clear with no milky streaks. With a melting pot, set your temperature dial and let it come up slowly. Either way, check with your thermometer before pouring or loading your injector.
Mixing Colors and Additives
Wait until the plastisol reaches its clear, melted state before adding colorants, glitter, salt, or scent. Stir these in slowly and gently. Vigorous mixing whips air into the plastic and creates micro-bubbles that show up as tiny voids in your finished lure. A few slow, deliberate passes with a craft stick or paddle mixer for two to four minutes is enough to distribute everything evenly. Be sure to scrape the bottom of the container, where pigment and heavier additives tend to settle.
For two-tone or “laminate” lures, you have a couple of options. With an open-pour mold, pour one color into the cavity first, let it partially set for 20 to 30 seconds to form a skin, then pour the second color on top. With a dual injector, load each chamber with a different color and inject them simultaneously so they swirl together inside the mold. This creates the classic two-tone look you see on commercial swimbaits and creature baits.
Pouring or Injecting the Mold
For open-pour molds, simply tilt the mold at a slight angle and pour the heated plastisol in a steady, thin stream from one end. The angle helps the plastic flow into thin appendages (tails, legs, tentacles) before air gets trapped there. Fill until the plastic is flush with the top of the cavity.
For aluminum injection molds, draw the heated plastisol into your injector, press the nozzle firmly against the mold’s sprue hole, and push the plunger with steady, even pressure. Don’t slam it. A smooth, controlled push fills the cavity without forcing air pockets into the bait. You’ll see a small amount of plastic squeeze out around the seam of the mold, which is normal. That flash trims off easily once the lure is cool.
Cooling and Demolding
Most lures are ready to pull from the mold in about one to two minutes. For a standard four-inch stick bait in a multi-cavity aluminum mold, setting a two-minute timer before demolding works well. The plastic should feel firm to the touch but still slightly warm. If you’re running many batches back to back, the mold itself heats up over time, so later pours may need an extra 30 seconds to a minute.
Gently flex the mold (if silicone) or separate the halves (if aluminum) and ease the lure out. Trim any flash along the seam line with scissors or a hobby knife. You can fish with lures right out of the mold, but they’re still curing internally. Freshly demolded baits are softer and more prone to bending or kinking if stored tightly. Letting them sit flat on a tray for a few days produces a more stable finished product. Some experienced lure makers cure their baits for a week or more before packaging.
Adjusting Lure Firmness
The flexibility of your finished lure determines how it moves in the water. A softer bait has more tail kick and lifelike wobble. A stiffer bait holds its shape better on the hook and lasts longer through multiple fish.
Most plastisol formulas come in soft, medium, and hard grades, so choosing the right base gets you most of the way there. For fine-tuning, you can add plastic softener to make baits more supple, or plastic hardener to stiffen them up. A good starting point for hardener is one tablespoon per cup of plastisol. For very stiff baits, like a jerkbait that needs to hold a precise glide, you can go up to a ratio of one part hardener to four parts plastic. Add small amounts, test a single bait, and adjust from there. It’s much easier to add more hardener to a batch than to try to soften one you’ve over-stiffened.
Avoiding Common Problems
Bubbles are the most frequent frustration for beginners. They come from three sources: mixing too fast, moisture contamination, or not heating evenly.
Always stir plastisol slowly. Never shake the container. If you see bubbles after mixing, use the reheat trick: bring the plastisol up to its clear melt stage, let it cool for about five minutes, then heat it back to melt stage. This gives trapped air time to rise to the surface and escape. The majority of bubbles disappear with this one technique.
Moisture is the other culprit. Even a small amount of water in your cup, on your stirring stick, or condensed inside a cold mold will cause the plastisol to bubble and spit when heated. Keep all your tools dry, and if your molds have been stored in a cold garage, let them come up to room temperature before use.
Incomplete fills usually mean the plastisol was too cool or you injected too slowly. If thin features like ribbon tails or split-tail ends aren’t forming properly, try working at the higher end of the temperature range (closer to 350°F) and applying slightly more pressure on the injector plunger.
Working Safely With Heated Plastisol
Heated plastisol releases fumes, primarily from the PVC and plasticizer compounds as they reach working temperature. These fumes are irritating to your lungs and should not be inhaled regularly. Work in a well-ventilated space, ideally with a window fan pulling air away from your work area, or outdoors. OSHA guidance for airborne contaminants prioritizes engineering controls like ventilation as the first line of defense.
If you’re making lures frequently or in larger batches, wear a respirator rated for organic vapors. A half-face respirator with P100 particulate filters combined with an organic vapor cartridge gives solid protection. At a minimum, keep your face out of the rising steam when you open the microwave or lift the lid on your melting pot. Use heat-resistant gloves when handling hot cups and molds. Plastisol at 320°F will cause an instant burn on contact with skin.
Storing Your Finished Lures
Soft plastic lures contain plasticizers that can migrate between baits of different formulas, causing colors to bleed into each other. Store each color and brand in its own bag. Some specialty soft plastics (particularly those made from a salt-based elastomer rather than PVC) will chemically melt standard soft plastics if stored together. Keep your homemade baits in individual zip-seal bags, sorted by color, and store them out of direct sunlight. Heat and UV exposure accelerate color fading and can make the plastic brittle over time.
Plastisol itself has a long shelf life in its liquid state. Keep unused plastisol sealed tightly in its original container at room temperature, and stir it thoroughly before each use. The heavier PVC particles settle to the bottom over time, so a good two to four minutes of gentle mixing before heating ensures a consistent pour every session.