Water based filler for larger gaps

For professional use only.

A water-based acrylic filler base for filling gaps. Mixed with sanding dust from the sanded floor, it is used for filling small gaps in floors. PreFill is quick drying and is to be used in combination with Junckers water-based priming and floor-finishing products.

PreFill is the ultimate water-based solution for floors made of wood species sensitive to changes in humidity.

Where to buy

Package Size:

5 Litres

General Description

Junckers PreFill is a quick drying filler-system to be used on indoor wooden floors in combination with water-based priming and floor-finishing products.

Water-based fillerbase to be mixed with sanding dust from the floor sanding process.

F 5.5

Surface Treatment Product Information PreFill Commercial / Residential

Product Description

Product: Water-based acrylic filler-base.

Appearance: Creamy/milky. When mixed with sanding dust from the sanding, the mixture dries up to the same colour as the wood.

Technical Data

Coverage: Approx. 5-20 m² per litre depending on the condition and the type of floor, e.g. Industrial Parquet: 6-8 m per litre.

Before application: Shake well before use.

Application tools: Broad full-edged spatula of stainless steel.

Surface temperature: Minimum 15° C and maximum 25° C

Dilution: Mix into sanding dust. Add Junckers PreFill to adjust the viscosity. Dilution with water is not recommended.

Drying time at 20° C and 50 % RH - NY:

45-90 minutes depending on film thickness.

Cleaning of tools: Soap and water immediately after use

Storage: Lasts for 1 year if unopened and stored at 20° C. Not to be exposed to temperatures below 5° C.

System Recommendations

High traffic areas:
1 coat Junckers PreFill
+ 1 coat Junckers PreLak 8 m²/litre
+ 2 coats Junckers STRONG 10 m²/litre or Junckers HP Commercial 10 m²/litre.

Low traffic areas:
1 coat Junckers PreFill
+ 1 coat Junckers PreLak 8 m²/litre
​+ 2 coat Junckers STRONG 10 m²/litre or Junckers ProFinish 10 m²/litre

Direction For Use

Untreated/sanded floors:
The floor surface should be clean, dry and free from dust, wax, grease, polish etc. Machine sand the surface to remove dirt and irregularities using sandpaper grit 120-150.

Mix enough Junckers PreFill into sanding dust until a thick but spreadable past is obtained. If too thick adjust with Junckers PreFill.

Spread the paste quickly using a stainless steel spatula. Let dry. Sand with sandpaper grit 120-150 to remove dried filler from the wood surface. Vacuum thoroughly.

Seal the floor and Leave to dry. Proceed according to one of Junckers “System recommendations”.

Previously sealed floors:
​Machine sand by first using sandpaper grit 24-36 to strip old coats. Then remove abrasion marks using grit 60-80. Finally, use grit 120-150 to obtain a completely smooth surface. Vacuum thoroughly. Treat the floor as described under “Untreated/ Sanded floors”.


Precautionary Measures

Before using the product, read the label on the container carefully and observe the recommended precautionary measures. See Material Safety Data Sheet for detailed information.

Further Information

F 4.2 - Junckers ProFinish
F 5.1 - Junckers STRONG
F 5.3 - Junckers PreLak
​F 8.5 - Junckers HP Commercial


Professional woodcare for Flooring

Safety data sheet - PreFill

Documentation PDF


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