California Department of Transportation
 

Tackifier

Tackifier is used as a glue for hydroseed treatments. Acceptable tackifiers include both plant based products, as well as polymeric emulsion blends. Select one of the tackifier products from the detailed information provided below.

When to Use this Product?

Specify a tackifier when filling out the Hydroseed specification.

Benefits/Limitations

Click here to view a chart comparing the benefits and limitations of various tackifiers.

If you are uncertain which tackifier to select, just specify guar.

Tackifier Types

Plant Material Based Tackifiers

Guar

Guar is a plant based product derived from the ground endosperm of the guar plant, treated with dispersant agents for easy mixing. Recommended minimum application rates are 5% to 10% of the weight of the hydraulic mulch (CASQA 2003a). Refer to manufacturer label for specific rates.

Recently the price of guar has skyrocketed as oil companies are using it in the "fracking" oil extraction process. Guar now (May 10, 2012) costs $9.80 per pound and looks as if it has become unaffordable for most erosion control work.

Psyllium

Psyllium is composed of the finely ground muciloid coating of plantago ovata seeds that is applied as a dry powder or in a wet slurry to the surface of the soil. It dries to form a firm but rewettable membrane that binds soil particles together but permits germination and growth of seed. Psyllium requires 12 to 18 hours drying time. Application rates are generally 80 to 200 pounds per acre, with enough water in solution to allow for a uniform slurry flow.

Psyllium is a good alternate to Guar tackifier. It is readily available, works well and is inexpensive. Psyllium is currently $38 for a 50-pound bag, or $0.76/pound.

Starch

Starch is non-ionic, cold-water soluble (pre-gelatinized) granular cornstarch. The material is mixed with water and applied at the rate of 150 pounds/acre. Approximate drying time is 9 to 12 hours.

 

Polymeric Emulsion Blend Tackifiers

Acrylic Copolymers and Polymers

Polymeric soil tackifiers should consist of a liquid or solid polymer or copolymer with an acrylic base that contains a minimum of 55% solids. The polymeric compound should be handled and mixed in a manner that will not cause foaming or should contain an anti-foaming agent. The polymeric emulsion should have a minimum shelf life of one year. Polymeric soil stabilizer should be readily miscible in water, non-injurious to seed or animal life, non-flammable, should provide surface soil stabilization for various soil types without totally inhibiting water infiltration, and should not re-emulsify when cured. The applied compound should air cure within a maximum of 36 to 48 hours. Liquid copolymer should be diluted at a rate of 10 parts water to 1 part polymer and applied to soil at a rate of 1,175 gallons per acre.

Liquid Polymers of Methacrylates and Acrylates

This material consists of a tackifier that is a liquid polymer of methacrylates and acrylates. It is an aqueous 100% acrylic emulsion blend of 40% solids by volume that is free from styrene, acetate, vinyl, ethoxylated surfactants or silicates. For soil stabilization applications, it is diluted with water and applied with a hydraulic seeder at the rate of 20 gallons per acre. Drying time is 12 to 18 hours after application.

Copolymers of Sodium Acrylates and Acrylamides

These materials are non-toxic, dry powders that are copolymers of sodium acrylate and acrylamide. They are mixed with water and applied to the soil surface for erosion control at rates that are determined by slope gradient:

Copolymer Tackifier Application Rate
Slope Gradient (H:V) Pounds/Acre
Flat to 5:1 3 - 5
5:1 to 3:1 5 - 10
2:1 to 1:1 10 - 20

Polyacrylamide and Copolymer of Acrylamide

Linear copolymer polyacrylamide is packaged as a dry-flowable solid. When used as a stand-alone tackifier, it is diluted at a rate of 10 pounds/1,000 gallons of water and applied at the rate of 5 pounds per acre.

Hydrocolloid Polymers

Hydrocolloid Polymers are various combinations of dry-flowable polyacrylamides, copolymers and hydrocolloid polymers that are mixed with water and applied to the soil surface at rates of 54 to 62 pounds per acre. Drying times are 0 to 4 hours.

Guidance:

References:

Updated 04-15-2014