Hesse HYDRO Filler

Single-component HYDRO primer, water-dilutable pigmented, thixotropic formula, machine-sandable, very good filling properties. Filling primer for closed-pore lacquer applications with good hold on vertical surfaces. Free from methylpyrrolidon. HP 6645-9343, in conjunction with HB 65285-(colour tone), is categorised as flame-retardant per DIN 4102 B1.



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.

  • Good body
  • Thixotropic

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

Intermediate lacquer sanding (grits) from-to

280 – 400


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.


  • Compressed air spraying

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.

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.

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.




HP 6645-9343


5 kg, 25 kg

Additional information

Product Type

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