SaBoFlex Plastisol Hardener (1 kg)

Product detailed description

SaBoFlex Plastisol Hardener is a liquid hardener designed to increase the hardness and shape stability of plastisol in a controlled way before it is heated. It is not a stand-alone plastisol, but a concentrated formulation additive that allows you to adjust the base mixture towards a firmer body, less deformation and more stable behaviour in the finished soft plastic lure. The pack contains 1 kg.

It is most useful when the base plastisol is too soft for a particular lure shape. A larger body may sag under its own weight, a pronounced tail may distort the lure’s overall profile at faster retrieve speeds, or the lure may not hold its shape sufficiently in strong current. The hardener is therefore particularly useful when making larger shads, swimbaits, tube lures, saltwater soft plastics, lures designed for strong currents and other shapes that require a firmer supporting body section.

The recommended starting dosage is approximately 3% by weight of the base plastisol. In practice, this means adding 30 g of hardener to 1 kg of cold plastisol. This amount should move the base SaBoFlex plastisol approximately one grade towards a firmer formulation. At this ratio, a 1 kg pack is sufficient for approximately 33 kg of plastisol.

The stated ratio is a starting point, not a guarantee of an identical result with every lure. The final hardness is affected by the original plastisol grade, the thickness and design of the casting, the amount of pigment and glitter, other additives and the processing method. Nor should the dosage be interpreted to mean automatically that 6% will produce a mixture exactly two grades harder. Every new recipe should therefore be tested separately.

How to add the hardener correctly: first homogenise the base plastisol thoroughly and shake the hardener well before use. Weigh the required amount on an accurate scale, add it to cold plastisol that has not yet been heated, and stir slowly until the mixture is completely uniform. Avoid vigorous mixing, which would unnecessarily introduce air into the plastisol.

If you are still fine-tuning the recipe, we recommend starting with several small, separate samples:

→ first sample: 1 g of hardener per 100 g of cold plastisol

→ second separate sample: 2 g of hardener per 100 g of plastisol

→ third separate sample: 3 g of hardener per 100 g of plastisol

Only the third sample represents the recommended starting dosage of 3%. The lower concentrations form a cautious workshop test series that will help you find a suitable intermediate grade without unnecessarily wasting material. Cast all samples in the same mould and keep the amount of pigment and glitter, the working temperature and the heating process identical.

Compare the results only after the samples have cooled completely and ideally after at least 24 hours of conditioning in a straight, flat position. Assess the stiffness of the body, recovery to its original shape, deformation under its own weight, tail activation at the intended retrieve speed, hook retention and the material’s behaviour during stretching and repeated use.

Increasing hardness always involves a trade-off. A firmer formulation holds its shape better and deforms less, but it can also reduce flexibility and the responsive action of thin tails or delicate appendages. If too much hardener is added, the lure may feel stiff and its tail may not activate properly until the retrieve speed is increased.

Harder does not automatically mean more resistant to every type of damage. Greater stiffness may improve shape stability and hook retention, but if flexibility is reduced too far, the material will not stretch as readily and may become more prone to damage at stress points. The aim is therefore not to produce the hardest possible mixture, but to find the lowest dosage that gives the lure the support it needs while preserving its correct action.

Hardener or a pre-formulated harder plastisol? SaBoFlex Plastisol Hardener is ideal for fine-tuning a specific recipe, creating custom intermediate grades and making use of existing stocks of softer plastisol. If you regularly need to prepare larger quantities of the same firmer mixture, it may be more practical to use the corresponding pre-formulated SaBoFlex plastisol grade, such as SOFT MEDIUM or MEDIUM. A pre-formulated plastisol makes it easier to reproduce the same result, while the hardener gives you greater scope to customise the formulation.

The hardener should not be confused with the SaBoFlex Plastisol Heat Stabilizer. The hardener changes the final firmness and mechanical behaviour of the lure, while the heat stabilizer helps protect the plastisol during heating and especially during repeated reheating. The two products perform different functions and cannot replace one another.

Always follow the processing temperature specified for the base plastisol being used. The hardener does not create a new processing temperature range, should not be heated separately and should not be added to plastisol that is already hot. Overheating the mixture can cause irreversible damage.

Wear suitable protective gloves, long clothing and eye protection while working. Heat plastisol only in a well-ventilated work area and use containers and equipment that are not used for food preparation. Store the hardener in its original, tightly closed container, in a dry place at a temperature of approximately 15–35 °C. Protect it from moisture, high temperatures and direct UV radiation.

Frequently Asked Questions – SaBoFlex Plastisol Hardener

Is SaBoFlex Plastisol Hardener a stand-alone plastisol?

No. It is a liquid additive designed to modify the hardness and shape stability of a base plastisol. It should neither be heated on its own nor poured into a mould.

How much hardener should I add?

The recommended starting dosage is approximately 3% by weight of the base plastisol, which means 30 g of hardener per 1 kg of plastisol. For a small test batch, the same ratio corresponds to 3 g of hardener per 100 g of plastisol.

Should I measure the hardener in grams or millilitres?

The recommended dosage is specified by weight, so weighing the hardener in grams provides the most accurate result. Converting the dosage to millilitres would require the exact density of the liquid and could reduce the repeatability of the recipe.

Does 3% always mean exactly one hardness grade?

Not exactly. It is an approximate shift because the final hardness is also affected by the base plastisol, the shape and thickness of the casting and the other components in the recipe. Always verify a new ratio using a small, separate test batch first.

Can I add the hardener to hot plastisol?

We do not recommend it. Add the hardener to cold plastisol before heating and mix it in thoroughly using slow stirring. This produces a more uniform mixture and a more repeatable result.

Does the hardener make the plastisol set faster?

The product’s main purpose is not to shorten the cooling or conditioning time, but to adjust the final hardness and flexibility of the lure. Processing and conditioning times continue to depend on the base plastisol, the size of the casting, the mould and the production process.

Does the hardener make the lure more durable?

Greater stiffness may improve shape stability, reduce deformation and help the lure remain more securely on the hook. However, it does not automatically provide greater resistance to every type of tearing. An excessively hard mixture loses flexibility, so it is important to find the correct balance between stiffness, action and durability for the particular lure shape.

How does the hardener affect lure action?

A firmer body can stabilise a larger lure in current or during faster retrieves. At the same time, it may limit the activation of a thin tail or small appendages at low speed. Every new recipe should therefore be tested in the same mould and using the type of retrieve for which the lure is intended.

What is the difference between the hardener and a pre-formulated harder plastisol?

The hardener allows you to adjust a particular recipe in small increments and create custom intermediate grades. A pre-formulated harder plastisol already has a defined final hardness and makes it easier to produce larger batches repeatedly with the same properties.

What is the difference between the hardener and a heat stabilizer?

The hardener changes the final firmness and flexibility of the soft plastic lure. A heat stabilizer helps protect the plastisol during heating and repeated reheating. The hardener therefore does not replace protection against heat damage to the plastisol.

Can I use the hardener with plastisol from another brand?

SaBoFlex Plastisol Hardener provides the most predictable results within the SaBoFlex system. Plastisols from other manufacturers may use different formulations, so any combination should first be tested in a small, separate batch. Check the uniformity of the mixture, clarity, behaviour during heating and the final hardness of the lure.

→ All detailed technical information is provided below in the Product Parameters table.

↓ Below the product description, you will also find related and similar products to help you choose and assemble a complete setup for making soft plastic lures.