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Just received a custom table finished with minwax water-based polyurethane. It's been about a week so I tested applying pressure with my fingernail, which did leave a small scratch if you look closely. I'm just wondering if this is expected for polyurethane finishes or if they should be completely scratch resistant. I'm mainly concerned with if it's fully cured or not (for health reasons)

If the expectation is that it should scratch a bit with my fingernail then that's fine with me. Just don't want to be using an desk that isn't fully cured because that might not be safe from what I've been reading.

More details from a comment posted below:

Since I don't know how hard a fully cured product feels, my main question was how can I tell if it is fully cured or not. The person who made the desk put on 7 coats within 20-30 min of each other spread out between 2 days, so people have told me it may never fully cure so I'm wondering if even if will never reach the expected hardness of a properly applied product, will it still be safe to use as a desk and occasionally eat on (its hard to tell from the smell since the water-based stuff has low odor)

FreeMan
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eric
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    Nothing is completely scratch resistant :-) – Volfram K Oct 09 '21 at 05:38
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    There is lots of info captured in previous Q&A. Search for "polyurethane scratch". –  Oct 09 '21 at 12:45
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    Hi, welcome to StackExchange. As already mentioned no finish is completely scratch resistant, although some industrial coatings get close! Waterbased poly is historically one of the poorest performers in this regard and also you picked what may be the poorest entry in that class (Minwax being frequently mentioned as bottom-tier stuff). – Graphus Oct 09 '21 at 14:59
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    Close enough to Water-based polyurethane Vs. Oil-based polyurethane that we could consider it a dupe? Additionally When can I sand water based polyurethane? I think covers the bases. – Graphus Oct 09 '21 at 15:01
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    Are your health concerns about having the table in the house before the finish is cured? If so, scratch resistance is the wrong question to be asking and it's too late, since it seems the table is already in your house. If it's about health concerns of a small child licking food off the table and getting some finish up, then ask that. Or, just simply ask what the cure time is of the product. Please clarify exactly what it is that you're concerned about. – FreeMan Oct 10 '21 at 17:52
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    Does this answer your question? Water-based polyurethane Vs. Oil-based polyurethane – Graphus Oct 11 '21 at 07:03
  • @FreeMan since i dont know how hard a fully cured product feels, my main question was how can i tell if it is fully cured or not. the person who made the desk put on 7 coats within 20-30 min of each other spread out between 2 days, so people have told me it may never fully cure so im wondering if even if will never reach the expected hardness of a properly applied product, will it still be safe to use as a desk and occasionally eat on (its hard to tell from the smell since the water-based stuff has low odor) – eric Oct 12 '21 at 00:48
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    @eric I've added your comment to the question itself. That's really were that info belongs - not everyone reads comments, and they can get deleted. In the future, please feel free to [edit] your own questions or answers to include additional details like these. – FreeMan Oct 12 '21 at 12:32
  • There's lots more ground I could cover here but one of the bottom lines here is that you haven't waited long enough for the finish to cure. Even if it had been applied more lightly it's still likely you haven't waited long enough, as previous Answers suggest. But put that aside for now, let me try to reassure you that you shouldn't have any health concerns about the finish — even if you were putting food directly on the surface and licking it off you'd probably still be safe! The health concerns about finish are consistently exaggerated and blown out of proportion (because, Internet) [contd] – Graphus Oct 12 '21 at 16:12
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    ...and (literally) nothing short of drinking the liquid finish or actively scraping it off and eating the flakes would be any sort of poisoning risk. – Graphus Oct 12 '21 at 16:16
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    @FreeMan thanks, this is my first post so I wasn't aware it could be edited – eric Oct 13 '21 at 04:17

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