Fillers for Polyurethane Thicken, lighten, strengthen, or create a metallic look : with our epoxy and polyurethane fillers, you can tailor every casting or laminating project to your exact requirements. Choose from thixotropic agents , lightweight microballoons , aluminum trihydrate (ATH) , metal powders , and chopped fiberglass for professional...
With this Polyurethane Filler (based on Aluminum tri-hydrate) you can increase the maximum casting thickness of the Polyurethane casting system D80 Set , into 80 mm instead of 30 mm. PU filler that is added to a polyurethane casting system increases...
Fumed Silica is a powder suitable for making liquid materials, thick or paste like. When mixed properly without air entrapment this powder will disolve colorless. This powder can also be used in Siliconen Culinair® because the result is still food safe....
This Aluminum powder consists of 100% Aluminum. Due to its fine composition, this Aluminum powder can be used for mixing in, for example, paints, lacquers, casting resins and plasters. Then you can sand the whole thing and apply a patina....
With this filler you get a lighter cast and consume less resin. Glass beads are very small perls of glass. The beads are so small that they can not be distinguish with the naked eye. The material looks like flour....
This iron powder consists of 100% iron. Due to its fine composition, this iron powder can be used for mixing in, for example, paints, lacquers, casting resins and plasters. Then you can sand the whole thing and apply a patina....
Glass fibres 12 mm can be used to reinforce all kinds of resins like Acrylic, polyester, pu, epoxy and even silicone. Cheap filler Easy to measure out Acrylic resin with glass fibres and glas fibre cloth is a strong cheap...
Glass fibres 6 mm can be used to reinforce all kinds of resins like Acrylic, polyester, pu, epoxy and even silicone. Cheap filler Easy to measure out Acrylic resin with glass fibres and glas fibre cloth is a strong cheap...
Glass fibres 3 mm can be used to reinforce all kinds of resins like Acrylic, polyester, pu, epoxy and even silicone. Cheap filler Easy to measure out Acrylic resin with glass fibres and glas fibre cloth is a strong cheap...
This copper powder consists of 100% copper. Due to its fine composition, this copper powder can be used for mixing in, for example, paints, lacquers, casting resins and plasters. Then you can sand the whole thing and apply a patina....
This brass powder consists of 100% brass. Due to its fine composition, this brass powder can be used for mixing in, for example, paints, lacquers, casting resins and plasters. Then you can sand the whole thing and apply a patina....
These ceramic microspheres are used to reduce the density of resins and other casting materials. These micro granules can be used in polyurethane, silicone, epoxy, polyester, plaster, concrete, cement and similar products. Technical data Melting point: 1200-1350°C Bulk density:...
A filler for, inter alia, acrylic resin Ages like metal Easy to process Suitable for cold and warm patina Description To create various metal effects, metal powder can be added to A1 acrylic resin. By slightly sanding the end result,...
This bronze powder consists of 100% yellowish bronze. Due to its fine composition, this bronze powder can be used for mixing in, for example, paints, lacquers, casting resins and plasters. Then you can sand the whole thing and apply a...
Fillers for Polyurethane
Thicken, lighten, strengthen, or create a metallic look : with our epoxy and polyurethane fillers, you can tailor every casting or laminating project to your exact requirements.
Choose from thixotropic agents , lightweight microballoons , aluminum trihydrate (ATH) , metal powders , and chopped fiberglass for professional results.
For whom: Professional users of epoxy, polyurethane and polyester resins who want to adapt their material for specific applications such as laminating, casting, spatula or cold casting.
Quick choice: which filler suits your purpose?
Goal
Recommended filler
Result
Thicken / make thixotropic
Fumed Silica (Aerosil / Cab-O-Sil)
Non-sagging mix, transparent
Lighten / save material
Hollow Glass Beads (Microballoons)
Lower density, better sanding
Harder/stiffer & flame retardant
Aluminum trihydrate (ATH)
Higher stiffness, FR action
Metal look / cold casting
Aluminum, Copper, Iron powder
Real metal sheen, patina possible
Mechanical reinforcement
Cut Fiberglass 12 mm
Higher impact/tensile strength
Key Benefits
✓Versatile for epoxy, PU, polyester and silicone
✓Adjustable to precisely adjust viscosity, weight and strength
✓Cost-effectively reduce resin consumption or extend material
✓Professional results for laminating, casting and spatulating
✓Creative metal effects and special finishes possible
Areas of application
→Composite construction lamination with fiberglass and reinforcement
→Moldmaking thixotropic layers and fairing compounds
Cold casting metal look sculptures and replicas
→Industrial parts rigid, lightweight components
Thixotropic & thickening: Fumed Silica for Epoxy & PU
Filler Fumed Silica 150 gr.
Fumed silica (known as Aerosil or Cab-O-Sil ) is the standard thixotropic agent for thickening epoxy, polyurethane, polyester, or silicone . When mixed properly, the mixture remains colorless/transparent.
Purpose: Pastes, spatulas, vertical laminates
Properties: increases viscosity, anti-sagging
Tip: process in small portions; avoid dust formation
Microscopic hollow glass beads for lightweight castings , syntactic foams, and fairing compounds . Reduces resin consumption and improves sandability.
Goal: Lose weight, increase volume
Compatible with: epoxy, PU, polyester
Tip: Do not mix too aggressively to reduce breakage.
Hardness & FR: Aluminum Trihydrate (ATH) for Polyurethane
Filler Polyurethane (ATH-based)
Aluminum trihydrate increases hardness and stiffness and can contribute to flame-retardant properties (formulation and dosage dependent). It also reduces the cost per kg of final mixture.
Purpose: stiffer parts, FR purposes
Use: Dose according to TDS; viscosity increases
Tip: degassing/lower casting thickness due to exotherm
Metal look & cold casting: Metal powders
Aluminum powder (100%)
Fine aluminum powder for metallic effects in paints, lacquers, casting resins, and plaster. After curing, polish to a shine or apply a finishing touch.
Copper powder (100%)
Copper powder creates a warm bronze/copper look . Suitable for cold casting ; patination is possible for an authentic effect.
Iron powder (100%)
Iron powder gives a robust steel/cast iron look . Create a rust patina for an industrial or antique finish.
Goal: realistic metal look, weight/feel tuning
Tip: first apply a thin "gel coat" with lots of powder, then fill it up
Reinforcement: Cut Fiberglass 12 mm
Cut Fiberglass 12 mm
Chopped strand for extra mechanical strength in acrylic resin, polyurethane, epoxy, polyester and even silicone.
Objective: Increase impact resistance and stiffness
ATH-based filler for a harder end result , higher stiffness and lower cost per kg PU.
Fumed Silica 150 gr.
Make epoxy/PU thixotropic for troweling and vertical applications; stays clear when used correctly.
Aluminum powder (100%)
For metallic effect in resin and plaster; polishing/patina possible for a realistic finish.
Filler Hollow Glass Beads
Creates lightweight castings and fairing compounds; reduces resin consumption and improves sandability.
Iron powder (100%)
For cold cast and rust patina effect; industrial character.
Cut Fiberglass 12 mm
Reinforced epoxy/PU/polyester; improved impact and tensile strength.
Copper powder (100%)
Warm copper/bronze look with the possibility of patination; ideal for decoration and replicas.
Getting Started with Fillers
Order fillers for epoxy, polyurethane, and polyester. Compare products, download datasheets, and contact us for technical advice and fast delivery in Europe.
Frequently Asked Questions (FAQ)
How much fumed silica do I need to thicken epoxy?
Start with small percentages (1-3%) and gradually increase until the desired thixotropy is achieved. Too much fumed silica can hinder miscibility and deaeration.
What is the difference between hollow glass beads and microballoons?
In practice, the terms are used interchangeably. Both are hollow glass microspheres that reduce density and facilitate abrasion.
Can I use ATH for fire retardancy in PU?
Yes, aluminum trihydrate is often used for FR purposes. Its effectiveness depends on the dosage and the overall formulation of the system.
How do I create a metallic look with casting resin?
Mix metal powder into the resin (possibly first a thin "gel coat" rich in powder), then pour on the standard mix and finish with polishing or patination for the desired effect.
Technical advice & ordering
Not sure which filler your project needs? We're happy to help with dosage, compatibility, and application advice.
Contact us for personal advice and fast delivery in Europe.
Note: Always follow the Technical Data Sheet (TDS) and Safety Data Sheet (SDS). Add fillers gradually and test a small batch before scaling up to larger volumes.
