Wood Primer Selection Guide: Hydrolux and Ankocryl Systems
Selecting the wrong wood primer is one of the most common causes of coating failure. Each primer in the Anker Stuy range has a specific role: adhesion, tannin blocking, filling, or a combination. Understanding those differences is what allows you to specify the right system for the substrate and end use.
This guide covers the full primer range across both the Hydrolux exterior primer and Ankocryl interior primer systems, with technical notes on each product and the substrate and application conditions they are designed for.
Hydrolux Exterior Wood Primers
All three Hydrolux exterior primers are formulated with Tri-Cryl® binder technology and are designed to work as part of the full Hydrolux system, used ahead of the Hydrolux Topcoat. Minimum application temperature is 8°C across all three, with a maximum humidity of 85%.
| Code | Product | Primary Function | Re-coatable |
|---|---|---|---|
| 17-0535 | Hydrolux Baseprimer | Adhesion, medium build | 2.5 hours |
| 17-0537 | Hydrolux Iso Primer | Tannin blocking, filling | 2.5 hours |
| 17-0540 | Hydrolux Filling Primer | High build, grain filling | 2.5 hours |
17-0535 Hydrolux Baseprimer
A medium-build waterborne opaque exterior wood primer with strong adhesion to both softwood and hardwood. Fully tintable and compatible with the Hydrolux topcoat system. It also accepts re-coating with solvent-based alkyd systems, giving flexibility where mixed systems are in use. Low propensity to run makes it practical on vertical faces and profiled sections. Suitable for Accoya.
17-0537 Hydrolux Iso Primer
The Hydrolux Iso Primer combines tannin-blocking performance with good filling properties. Tannin bleed is a known issue on species like oak, iroko, and certain tropical hardwoods. Extractives migrate through the coating and cause discolouration, particularly under lighter topcoat colours. The 17-0537 is formulated to prevent this. It covers at 175-200 microns and sands easily. Suitable for all timber substrates including Accoya and softwoods.
Also available in grey for use under dark topcoat colours.
17-0540 Hydrolux Filling Primer
A high-build exterior primer with strong grain-filling characteristics. It is particularly well suited to laminated and finger-jointed components where surface uniformity is important. The high build helps level out the difference in porosity between join lines and the surrounding timber face. Very low water uptake and strong wet adhesion. Suitable for all exterior substrates including Accoya and softwoods.
Also available in colour.
- Clear-grained softwoods and standard hardwoods: 17-0535 Baseprimer
- Tannin-rich species including oak, iroko and tropical hardwoods: 17-0537 Iso Primer
- Laminated, finger-jointed or uneven-porosity timber: 17-0540 Filling Primer
Always refer to the relevant Technical Data Sheet and system specification before use.
Ankocryl Interior Wood Primers
The Ankocryl interior primer range covers both standard and tannin-rich timber substrates. Both waterborne primers are designed for use ahead of the Ankocryl Interior Topcoat. Minimum application temperature is 18°C for both.
| Code | Product | Primary Function | Re-coatable |
|---|---|---|---|
| 17-0556 | Ankocryl Interior Primer | Adhesion, opacity, standard timbers | 4 hours |
| 17-0559 | Ankocryl Interior ISO Primer | Tannin blocking, grain filling | 4 hours |
17-0556 Ankocryl Interior Primer
A waterborne acrylic dispersion interior wood primer with high opacity and strong adhesion. Formulated for non-tannin-rich interior timbers. High hiding power, good flow, and excellent stackability make it well suited to production line processing. Available in white and grey.
17-0559 Ankocryl Interior ISO Primer
A grain-filling tannin-blocking interior primer formulated with Tri-Cryl® technology. The key difference from the standard 17-0556 is its ability to isolate and block tannins and discolouring stains. This is important when working with oak, teak, and other tannin-heavy interior timbers where bleed-through under light topcoat colours is a risk.
If tannins remain visible after the first coat, a second coat after 24 hours is required before proceeding with topcoats. Available in white and grey.
- MDF, pine, and non-tannin-rich hardwoods: 17-0556 Interior Primer
- Oak, teak, and tannin-rich timbers: 17-0559 Interior ISO Primer
Always refer to the relevant Technical Data Sheet and system specification before use.
Tannin Bleed in Timber Coatings
Tannins are water-soluble extractives present in varying concentrations across different timber species. When a waterborne primer is applied, moisture from the coating can carry tannins to the surface before the film forms, resulting in yellow or brown discolouration that is most visible under white and pale topcoats.
Species where tannin bleed is most commonly seen include oak, iroko, teak, western red cedar, and certain tropical hardwoods. The ISO primers in both the Hydrolux and Ankocryl ranges are specifically formulated to block this migration. On very high-tannin species, or where discolouration persists after the first coat, a second primer coat should be applied before topcoating.
White vs Grey Primers
Several primers across both ranges are available in white and grey. Grey-tinted primers are intended for use under dark topcoat colours. Using a white primer under a dark topcoat typically requires additional topcoat passes to achieve full opacity and colour uniformity. A grey primer provides a more neutral base, reducing the number of coats needed and improving colour consistency, particularly on edges and profiled sections where film build is harder to control.
