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What species of timber can cause tannin bleed with water-based coatings?

High-tannin species that commonly cause tannin bleed under waterborne coatings: Blackbutt, Forest Red Gum, Grey Ironbark, Ironbark (generic), Merbau, Red Bloodwood, Red Ironbark, River Red Gum, Tallowwood, Turpentine, Western Australian Blackbutt. Bona Intense is the primer Bona specifies for this class; Bona Classic, Classic UX and White are not recommended.

High-tannin species (Bona Intense recommended; Classic, Classic UX and White are not recommended):
Blackbutt, Forest Red Gum, Grey Ironbark, Ironbark (generic), Merbau, Red Bloodwood, Red Ironbark, River Red Gum, Tallowwood, Turpentine, Western Australian Blackbutt.

Medium-to-high tannin species (Bona Intense is the safer default; Classic / Classic UX / White are 'unlisted' or not recommended for dark ones):
American Oak, Blackwood, European Oak, Grey Box, Grey Gum, Jarrah, Oak (generic).

Bona's own Primers brochure is explicit: Bona Classic 'should not be used on high tannin timber species', Bona Classic UX is 'not recommended for high tannin timber species', Bona White is 'not recommended for high tannin or darker timbers'. Bona Intense is 'specifically recommended on timber species with high tannin content such as Blackbutt and Tallowwood'.

Sources: Bona Primers Range Brochure (Ed 4), Bona Classic TDS AU (2025-03-25), Bona Classic UX TDS AU (2025-03-25), Bona Intense TDS AU (2025-03-25), Bona White TDS AU (2025-03-25).

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