Hesse COOL-FILL HP 6645-(colour tone)

  • Good body
  • Thixotropic
This 1C isolating filler is formulated to be thixotropic and have good body. It is therefore ideally suited as a filler for closed-pore surface processes with good ability to stay on vertical surfaces. Acrylate-based COOL-FILL can be machine sanded and can be recoated using both HYDRO colour lacquers and NC or PU colour lacquers. COOL-FILL HP 6645-9343 in combination with HB 65285-(colour tone) is certified under “Dubai Green Building” and classified as flame retardant under DIN EN 13501-1.
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  • Description
  • Information on use
  • Sample process
  • Safety Data Sheets / Certificates

Fields of application

For all interior fittings in living areas, on an extremely wide range of wood types, priming foils and MDF, and MDF including edges. For furniture surfaces throughout all interiors; for stairs, doors, ledges, etc.

Technical specifications

Appearance opaque
Decopaint basis WB
Decopaint category I
Density series kg/l 1.344 - 1.369
Flow time (+/- 15 %) 26 s / DIN 53211 - 6 mm
Form of delivery fluid
Non-volatile content series % 57 - 62
VOC EU % 5.82 %
Number of coats (max) 3
Amount per layer (minimum) 120 g/m²
Amount per layer (max) 300 g/m²
Total application volume 600 g/m²

Information on use

Drying 2 h / 20°C
Stackable after > 16 h / 20 °C
Complete drying 1 h / 20°C
Surface preparation Clean, dry wood, free of oil, grease, wax and silicones. Sanded as prescribed and free from sanding dust.
Substrate sanding grits from-to 120 - 400
Lacquer sanding (grit) from - to 280 - 400
Finishing Recoatability: Can be coated over after sufficient drying time and intermediate sanding, e.g. with HB 65285-(colour tone), HDB 54705-(colour tone). Can also be coated with commonly used HYDRO, PU or CN coloured lacquers and with most standard paints. (Test coat required!)
Comments on sanding Along with the MDF quality and the film quality, the quality and uniformity of the wood sanding, MDF sanding or foil sanding, as well as the lacquer sanding, are critical for the quality of the final surface. After sanding, remove dust as prescribed.
Yield per coat 5 - 11 m²/l

The spreading rate is heavily dependent on the type of application. The specifications relate to a liter of ready-for-use product, if necessary including hardener and thinner.
Working Temperature Range 18 - 22 °C
Storage temperature 10 - 30 °C
conditions of transport 10 - 30 °C
Processing instructions When directly coating cleaned or sanded foils, please apply a test coat to check the bonding! Clean tools with water. For removal of dried lacquer residues use Hesse HYDRO Cleaning agent HV 6917. In case of combined coatings (HYDRO- and solvent based lacquers) rinse application tools with Hesse HYDRO Reversing agent HV 6904. This product must only be combined with other approved and technically suitable products when used as a flame retardant coating material for seagoing vessels according to the latest version of SOLAS 74/88 Reg. II-2/3, II-2/5 and II-2/6, IMO Resolution MSC.36(63)-(1994 HSC-Code) 7 and IMO Resolution MSC.97(73)-(2000 HSC-Code) 7. The maximum application amount in wet film when using this product as a flame retardant coating material for seagoing vessels is 150 g/m².
Particular instructions Woods rich in active substances, such as ash, which tend to discolour when coated with pastel-coloured HYDRO colour systems should always be pre-treated with dual-component primers, such as: HDP 5640-9343. Pre-prime exotic woods such as Macassar ebony or extremely resinous knotty pine with PU Isolating primer DG 4720-0001. “A risk assessment was undertaken according to Directive 2014/90/EU, Annex II, Section 3. This coating does not pose a physical risk to health nor a risk to the environment when cured and dried.”
General instructions on workmanship When working with HYDRO materials, parts that come into contact with the material must be made from stainless steel. The moisture content should be between 8 - 12 %. Do not apply or dry HYDRO lacquers at material or room temperatures below 18 °C. The ideal humidity for application lies between 55 and 65 %. During the lacquering process, a humidity level that is too low leads to surface defects (such as shrink cracks, etc.). Excessive humidity during the drying phase may drastically lengthen the drying time! In order to avoid adhesion problems, please sand the lacquered surfaces freshly before coating and apply lacquer to the sanded surfaces as soon as possible. When applied to foils, etc., please use a sample coating on the respective substrate to check the adhesion! The ideal complete hardening of lacquered surfaces that have been flashed off is reached at temperatures over 20 °C up to no more than 40 °C. Adequate, draft-free air exchange must be assured. The complete hardening of the lacquer will be reached after one week of proper storage (at least 20 °C room temperature). Woods containing large amounts of natural oils, such as teak, can negatively influence adhesion under certain circumstances. Water-soluble wood ingredients such those in ash and tannins in woods such as oak may cause colour changes and discolourations in the coating. We recommend that you always conduct a sample lacquering to evaluate the colour effect, adhesion and drying process under real conditions! With MDF coatings, you can avoid painting faults and edge breaks if you observe the following: Selection of a suitable MDF quality for the area of application, see manufacturer data on EU standard EN 622-5, pt. 4 Test method EN 317 (requirements on thickness swelling). Ideal panel moisture 5 - 7 %. If possible coat the MDF all around, the backs should at least receive a clear coating. Avoid sharp edges and cutaways, round-off wherever possible. Coat edges and cutaways 2x with primers, do not sand through, if need be, prime again. Thick boards that have been created by gluing together several thinner boards are, due to the variance in tension, susceptible to edge ridging. It is better to select a single MDF board of the appropriate thickness. Panels that have been glued together should always be sanded flat at the edges and colourlessly pre-insulated. Any water introduced by gluing must be allowed to evaporate prior to coating. Store primer-coated surfaces in an air conditioned location and apply the final coat in a timely manner.

Substrate sanding: e.g. 220 - 280 grit with subsequent dust removal.
Basecoat 2 x 130 - 150 g/m² Hesse COOL-FILL HP 6645-9343.
Intermediate drying: at least 4 h / 20 °C, preferably 16 h / 20 °C room temperature with adequate air circulation. Graduated intermediate sanding from 240 - 320 grit with subsequent dust removal.
Top coat 1 x 110 - 130 g/m² Hesse COOL-COLOR HB 65285-9010.
Packable: after drying for at least 16 h / 20 °C room-temperature with adequate air circulation.


Our technical information is continually adapted to keep up to date with the latest technology and statutory regulations. The latest version is always available online at www.hesse-lignal.de or talk to your local account manager. This information is for advice and is based on the best knowledge available and careful research in line with the current state of the art. This information cannot be held as legally binding. We also refer you to our terms and conditions of business. Safety data sheet is provided in accordance with EC regulation no. 1907/2006.