Do It Soft Plastic Molds

A bass explodes on a lure you poured with your own hands. That strike feels different. Deeper. More earned. The color, the glitter, the exact tail shape that triggered the bite all came from decisions you made at a workbench. This is what Do-It soft plastic molds unlock for anglers tired of buying the same mass-produced baits as everyone else on the water.

Do-It Molds is the dominant name in American DIY lure making. For over fifty-five years, the company has poured and tested every mold that leaves its facility in Denver, Iowa. The brand started with lead jig molds. Today it offers close to 700 different mold designs, including a growing family of soft plastic bait molds that produce everything from 5-inch Senko-style stick worms to intricate swimbait bodies with paddle tails and segmented joints.

Making your own soft plastics is not complicated. You heat liquid plastisol until it turns clear and syrupy, inject it into an aluminum mold, and wait roughly thirty to sixty seconds for it to harden. The process sits somewhere between baking and industrial manufacturing. It rewards patience and punishes carelessness. Molten plastic at 350 degrees Fahrenheit demands respect. The payoff is a box full of custom baits in colors no tackle shop stocks.

Why Anglers Choose Do-It Molds Over Store-Bought Baits

Store shelves hold rows of identical baits. A factory somewhere made a million copies of the same green pumpkin worm. That worm catches fish. But so does the one you tinted slightly darker, with a hint of blue flake in the belly and extra salt for a faster sink rate. That bait does not exist anywhere else on the planet.

Do-It soft plastic molds give you control over every variable. Plastic hardness. Salt content. Glitter density. Color combinations that mimic the exact forage in your home lake. You can laminate two colors into a single bait using a dual injector, creating a natural shiner belly or a crawfish claw pattern that commercial manufacturers never produce.

The economics shift in your favor over time. A gallon of plastisol costs roughly fifty dollars and produces between four hundred and six hundred stick baits when you remelt your sprues. That puts per-bait material cost around eight to twelve cents. A single pack of five name-brand Senkos runs eight dollars at retail. The math is not subtle.

Beyond the money, there is the quiet satisfaction of catching a fish on something you made. That feeling never gets old.

The Do-It Mold Lineup: Essential Series vs. Precision Series

Do-It splits its soft plastic molds into two main lines. The distinction matters for your budget and your expectations.

Essential Series (ES)

The Essential Series uses sand-cast aluminum. The manufacturing process leaves a slightly textured surface on the bait. Some lure makers prefer this texture, arguing it creates micro-bubbles that hold scent longer. Others want a glass-smooth finish. The texture is subtle enough that once a Senko is in the water, neither the angler nor the fish can tell the difference.

Essential Series molds cost less to produce, and that savings passes to you. Most ES molds range from $54.99 for a standard four-cavity design up to $94.99 for the larger XL models with additional cavities. A starter angler can pick up an ES Senko mold, a quart of plastisol, colorant, and glitter for roughly the cost of a few dozen bags of store-bought baits.

The ES XL Series launched in 2022 as a response to rising bait prices. These molds feature more cavities and larger bait sizes. Do-It designed them for efficiency: “more baits, less bucks.” The XL Hatchet Craw, XL Shock Shad, and XL Wave Worm all run at $94.99 MSRP and pour several baits per injection cycle.

Precision Series

The Precision Series uses CNC-machined aluminum. The finish is mirror-smooth. The baits come out shiny and detailed. These molds cost more to manufacture and sell for $79.99 to $109.99.

CNC molds cost roughly double what sand-cast molds cost. The Custom Baits forum confirms the trade-off: “You can get three or more Essential Series molds for the price you would pay for just one CNC mold.” Both series produce fish-catching baits. The Precision Series simply does it with a finer surface finish.

Open Pour vs. Injection Molds

Do-It offers both styles. Open pour molds let you pour heated plastisol directly into an open cavity from the top. They require no injector and cost less. The bait comes out with a flat back — fine for worms and creature baits fished on the bottom.

Injection molds require an injector. You clamp the two mold halves together and pressurize the plastisol into the closed cavity through a port. The result is a fully rounded bait with detail on all sides. Swimbait, paddle tail, and craw molds almost always use injection design.

What You Need to Get Started With Do-It Soft Plastic Molds

The shopping list is short. The commitment to safety is not.

The Core Equipment

A mold is your starting point. Most anglers begin with a Senko stick mold or a simple grub mold. The Do-It ES Series 5-inch Senko produces four identical stick baits per injection and matches the exact specifications of the legendary Gary Yamamoto original.

An injector moves the hot plastisol from your cup into the mold. Do-It sells single injectors starting at $64.99. The dual injector allows two-color laminates and breaks down into two single injectors, making it a flexible upgrade.

A dedicated microwave heats the plastisol. Never use the kitchen microwave. Once plastic goes in, food never goes in again. The microwave sits in the garage or workshop, permanently assigned to bait duty.

Pyrex measuring cups hold the plastisol during heating. Use thick glass that can handle sudden temperature swings. Forum veterans recommend having at least two cups so you can heat one color while injecting another.

A digital infrared thermometer tells you when the plastic reaches 350 degrees. Guessing leads to scorched plastic, ruined color, and wasted material.

The Consumables

Plastisol is the liquid PVC-based compound that turns into your bait. Do-It sells its Essentials Series Plastisol in one-quart ($24.99) and one-gallon sizes. The formula turns clear when heated, fills molds cleanly, and sets in 30 to 60 seconds. Medium-formula plastisol works for most freshwater applications: worms, craws, swimbaits, and panfish plastics.

Colorant comes in sixteen shades. A few drops tint an entire batch. Glitter flakes in multiple sizes add flash. Heat stabilizer prevents scorching when you reheat leftover plastic multiple times. Worm oil keeps finished baits from sticking together in storage.

The Do-It Essentials Series Starter Kit bundles these basics at $109.99. It is the fastest path from curiosity to finished bait.

The Safety Gear You Cannot Skip

Molten plastisol at 350 degrees causes instant, severe burns. The fumes contain volatile organic compounds that cause headaches and, over time, potential respiratory damage.

Heat-resistant gloves protect your hands during injection. The injector barrel itself heats up once filled with 300-plus-degree plastic. Safety glasses guard against splashes. A 3M respirator with organic vapor cartridges filters the fumes. Forum consensus is unanimous: “I don’t ever shoot plastics without my respirator.”

Ventilation matters. Work in a garage with the door open. A fan blowing across the work area pushes fumes away from your breathing zone. Long pants, closed shoes, and a work apron complete the protection.

Step-by-Step: Using Do-It Soft Plastic Molds

1. Preheat the Mold

A cold mold shocks the plastisol. The plastic cools before it fills every detail, leaving rounded edges and missing appendages. Place the mold near a heat source or briefly warm it in the microwave. Some makers pour a practice shot of clear plastic just to bring the mold up to temperature. Preheat also prevents thermal cracking in sand-cast aluminum molds.

2. Prepare the Plastisol

Pour four to eight ounces of liquid plastisol into a Pyrex measuring cup. Stir — do not shake — the plastisol before heating. Shaking introduces air bubbles that become pinholes in finished baits. Add a pinch of heat stabilizer if you plan to remelt sprues later.

Microwave in 30-second increments. After each interval, remove the cup with a gloved hand, stir gently, and check temperature with the infrared thermometer. The first time you heat virgin plastisol, it needs to reach roughly 350 degrees Fahrenheit to fully convert.

The plastic turns from opaque white to clear as it reaches temperature. You are looking for a syrup-like consistency that pours in a steady, even stream.

3. Add Color and Glitter

Once the plastisol is clear and fluid, add colorant drop by drop. A little goes a long way. Two or three drops of watermelon colorant turn an entire four-ounce batch a convincing natural green. Stir thoroughly. Add glitter and hi-lite powders next. The plastic remains workable for several minutes, so do not rush.

For reheats, keep the temperature lower — around 300 to 325 degrees — to avoid scorching the plastic and burning the glitter.

4. Inject the Mold

Brush a thin layer of mold oil onto the cavity surfaces. A few drops on a small brush are enough. Clamp the mold halves together firmly. Some anglers use a bench vise or C-clamp for consistent pressure.

Draw the heated plastisol into the injector by pulling the plunger slowly. Invert the injector and gently push the plunger until a small bead of plastic appears at the tip, purging any trapped air.

Place the injector tip into the mold’s injection port. Push the plunger at a steady, even pace. Do not rush. “Inject slow and steady, hold pressure for 10 or so seconds, then top off.” Hold pressure long enough for the plastic to begin cooling. This prevents sink marks and incomplete fills.

After injecting, carefully push remaining plastic out of the injector nozzle as you withdraw the tip. This prevents a dried plug of plastic from jamming the nozzle for the next shot.

5. Demold and Cure

Wait 30 to 60 seconds. Open the mold. The bait should release cleanly. If it sticks, the mold may need more oil or preheating.

Let finished baits cure for 24 hours before bagging or fishing them. Fresh baits continue to harden as residual solvents evaporate. Bagging too soon traps moisture and causes the baits to stick together or deform.

Cost Breakdown: What Each Bait Actually Costs

The numbers matter. Most anglers make back their initial investment within a season of regular fishing.

A gallon of plastisol costs between $45 and $55 and produces roughly 640 stick baits when you remelt sprues. At $50 per gallon, that is about eight cents per bait in raw plastic cost. Colorant and glitter add a penny or two. Salt and softener add another fraction.

Counting all consumables, a hand-poured 5-inch Senko costs about 10 to 15 cents in materials. The same bait retails for roughly $1.50 each in a bag. The savings per bait are dramatic. The catch is that you must pour hundreds of baits before the equipment cost amortizes.

Initial startup cost with the Starter Kit, injector, safety gear, and a dedicated microwave runs between $200 and $300. At 15 cents per bait versus $1.50 retail, you break even after roughly 200 baits. A weekend angler who goes through a bag a week hits that number in under a month.

The table below maps typical startup and per-bait costs.

Common Mistakes That Ruin a Pour

Overheating the plastisol. Plastic scorched above 360 degrees turns yellow, then amber, then brown. The smell is acrid and unmistakable. Scorched plastic cannot be saved. Remove it from the microwave immediately. On reheats, stay at 300 to 325 degrees.

Pouring too fast. Rushing the injector traps air. Air becomes voids, missing tails, and wasted plastic. Inject at a deliberate pace and hold steady pressure for a ten-count after the cavity is full.

Skipping mold preheat. A cold mold cools the plastisol before it can flow into thin appendages. Craw claws and swimbait tails come out rounded and blunt. Preheating fixes this entirely.

Forgetting to purge the injector. Air trapped in the injector barrel pushes into the mold cavity ahead of the plastic. The result is surface pitting and internal bubbles. Invert the injector, push until plastic appears at the tip, then inject.

Storing baits before curing. Fresh demolded baits need 24 hours to off-gas and fully harden. Bagging them early traps moisture. Baits stick together, warp, and develop a cloudy surface film.

Neglecting ventilation and PPE. The fumes from heated plastisol are not harmless. A respirator is not optional. Neither are heat-resistant gloves. Every experienced lure maker on every forum repeats this advice. They do not repeat it because it is dramatic. They repeat it because they have all been burned at least once.

Tips From the Forum Veterans

The collective knowledge on Do-It’s own forum, Tackle Underground, Custom Baits, and Walleye Central is deep. Here are the patterns that repeat across thousands of posts.

Keep a notebook. Write down every variable: plastic brand, amount, cooking time, color drops, glitter type, injection temperature. When you hit a color you love, you can recreate it exactly. When something goes wrong, you can trace the mistake.

Heat virgin plastisol to 350 the first time. On reheats, stay under 325. Scorching changes the plastic’s flexibility and ruins glitter.

Brush mold oil lightly. Too much oil pools in the cavity and leaves shiny wet spots on the bait. Too little causes sticking. A thin film wiped almost dry is the sweet spot.

The Do-It Essential Senko mold produces an exact copy of the Gary Yamamoto Senko profile. The texture difference is minimal. In the water, the fish cannot tell which bait cost eight cents and which cost a dollar fifty.

Work in the garage, not the basement. “NEVER cook food in a microwave that has been used to cook plastic. You will want to work in a well-ventilated area preferably not in your home. I shoot baits in my garage.”

Maintaining Your Do-It Molds

Aluminum molds last for thousands of pours with basic care. Clean residue after each session with warm water and a soft brush. Do not use metal scrapers. A scratch in the cavity surface becomes a cosmetic flaw on every bait you pour from that mold forward.

Inspect the mold faces before each use. A dent or ding prevents the two halves from sealing, which causes plastic flash along the parting line. Flash is a thin sheet of excess plastic that must be trimmed from each bait. A few seconds of inspection saves ten minutes of cleanup.

Store molds in a dry location. Humidity causes surface oxidation that interferes with heat transfer and can stain light-colored baits. A sealed plastic bin with a desiccant packet works well.

Apply a light coat of mold release before long-term storage. This protects the aluminum and ensures the mold is ready for the next session.

Key Takeaways

• Do-It soft plastic molds turn ordinary anglers into bait makers. The Essential Series (sand-cast aluminum, $54.99–$94.99) offers the best value for beginners. The Precision Series (CNC-machined, $79.99–$109.99) provides a smoother finish for experienced makers.
• Startup cost runs $200–$300 for a complete kit including the Starter Kit, injector, respirator, gloves, Pyrex cups, and a dedicated microwave. Material cost per bait drops to 10–15 cents, compared to $1.50 or more at retail.
• Safety is non-negotiable. Heated plastisol reaches 350 degrees Fahrenheit. A respirator with organic vapor filters, heat-resistant gloves, safety glasses, and garage-level ventilation are mandatory, not optional.
• The process is straightforward: heat plastisol until clear, add color and glitter, inject slowly into a preheated and lubricated mold, hold pressure, demold after 30–60 seconds, and cure for 24 hours before bagging.
• Technique improves fast. Preheat the mold, purge air from the injector, hold steady pressure during injection, and keep a notebook of every variable. Within a few sessions, your baits look and fish like factory products.

Frequently Asked Questions (FAQ)

What are Do-It soft plastic molds made of?

Do-It soft plastic molds are made from aluminum. The Essential Series uses sand-cast aluminum, which has a slightly textured surface. The Precision Series uses CNC-machined aluminum for a smooth, glossy finish. Both conduct heat well, resist warping, and last for thousands of injection cycles.

How much does it cost to start making soft plastic baits with Do-It molds?

A complete startup with a Do-It Essentials Starter Kit ($109.99) , an injector ($64.99) , a used microwave, a respirator, gloves, and Pyrex cups totals approximately $200 to $300. Once equipped, material cost per standard stick bait is roughly ten to fifteen cents including plastisol, colorant, and glitter.

What temperature do I heat plastisol to for Do-It molds?

Heat virgin plastisol to roughly 350 degrees Fahrenheit on the first heat cycle. The plastic turns from opaque white to clear when ready. On reheats, stay between 300 and 325 degrees Fahrenheit to avoid scorching the plastic and burning glitter. Use a digital infrared thermometer to verify temperature.

Which Do-It mold is best for beginners?

The Do-It Essential Series 5-inch Senko Mold ($54.99) is the most recommended starter mold. It produces four identical stick baits per injection and matches the exact specifications of the Gary Yamamoto Senko. Stick baits are forgiving shapes that build injection skills before moving to complex craw or swimbait molds.

Can I use a kitchen microwave to heat plastisol?

No. A dedicated microwave reserved only for plastisol is required. Once plastic has been heated in a microwave, that microwave is permanently unsafe for food preparation. Use a secondhand microwave in the garage or workshop.

How long do Do-It soft plastic molds last?

With proper care — cleaning after each session, avoiding metal scrapers, and storing in a dry location — aluminum Do-It molds last for thousands of injection cycles. The sand-cast Essential Series may show surface oxidation over years but continues to produce quality baits.

How do I prevent bubbles in my soft plastic baits?

Preheat the mold, stir plastisol gently without shaking, purge air from the injector before injecting, and inject at a slow, steady pace. Hold pressure for ten seconds after the cavity fills. Let heated plastic sit briefly after the microwave cycle to allow bubbles to rise before drawing into the injector.

Do I need a dual injector for two-color baits?

Yes. A dual injector draws two separate colors of plastisol into a single nozzle and laminates them during injection. Do-It’s dual injector breaks down into two single injectors, making it versatile for both single-color and laminate pours. Both colors must be within 15 degrees of the same temperature for consistent flow.