I have a soft wet wood support beam, as described here. I bought some wood hardener. Instructions say to not apply to wet wood, only dry. I just wonder how that makes sense. I need the hardener liquid to penetrate the wood as much as possible. Water will creep along a wet surface better than a dry surface. I believe the wicking action of a wet surface will get the harder deeper into the wood. OTOH, they must have a reason for the guidance. Is it that the hardener would trap the water inside the wood fibers and be unable to escape?

If I use a hair dryer or something to dry the wood out as much as possible, is there anything I can do to improve the penetration of the hardener? I suppose I could make holes but of course that’s probably a bad idea in this case.

I should also mention that the hardener is water-based, which adds to my bafflement. The PDF says “Substrates must be cohesive, clean, sound and dry.” But the 2nd bullet on the webpage says “Adheres to damp wood”. Webpage also says “Surfaces:
Can be applied to any types of woods, absorbent
wood, dry or damp, including exotic species, chipboard and plywood sanded or stripped beforehand. ... Directions for use:
Do not apply to soggy wood.”

It’s confusing but all their statements together seem to suggest it’s okay to apply to wet wood, but not ideal or optimal. Though my intuition would be to favor slightly damp wood to get wicking effects.

The version I've used before penetrated really well on dry wood. If yours is water based, I'd assume the more moisture present, the weaker the bond, like diluting it.

It's https://en.wikipedia.org/wiki/Law_of_mass_action mostly; also for cross-linking, polymer chunks should be brought close to each other to make better bonds. Wood will absorb the compound better when dry, as it'll have higher surface energy and no water trapped to be displaced as compound moves in.

Yeah I think dilution is the intuition OP was missing too, well phrased