Fillers can be used for modifying characteristics of a resin system. Microballoons will increase viscosity while reducing weight and strength. Fumed silica increases the viscosity. Cotton flock increases the viscosity and the strength of the resin system. These can be used in combination to tailor the resin system to your application.

The use of fillers is not usually a precise science. Whichever filler you select can be added until the desired effect is achieved. Microballoons are a common filler, and when used in large quantity, make a lightweight syntactic foam. This can be used as a surface filler and molding putty.

Cotton Flock

Cotton fibers used in resin systems as a structural filler. Often used in corners or where a thick resin is required.

Quantity	Price
1 lb. bag	$3.75	Order!
5 lb. bag	$15.75	Order!

Fumed Silica

A thixotropic filler which is added to resin systems to prevent runoff. In higher ratios it can make a gel used for fillers and adhesives.

Quantity	Price
Gallon	$11.00	Order!

Glass Microballoons

Hollow glass microspheres for making a lightweight surface filler or syntactic foam.

Quantity	Price
Gallon	$7.90	Order!

Calcium Carbonate

High density filler used for making epoxy surface coats.

Quantity	Price
5 pounds	$5.00	Order!