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Had an email today about a board that had started to split. This was a new board. We're wondering why this failed so badly - the only other time I've seen a stringy separation like this was when heat was involved, but our exposure to these failures is limited so I wanted to get feedback.

Glue is Tightbond 3, joints were let to set for 24 hours, we lightly oiled it (good coat on both sides, let it soak in) and put some beeswax/oil mix on before it left for its new home. The owners said that they had only used it a couple of times when the crack started to appear, and that they had not let it sit in water.

We do live in a very humid area, but the wood had been.. what's the word, "equalized?". Basically we let it sit for a few weeks before actually doing anything with it. We had mostly finished the board and let it sit for almost three weeks before giving it a final sand and oil, unsure if that may have been related.

separation point top view another angle

  • The basic answer here may be that part of the board got wet (it doesn't matter if you oiled it or how well, the wood can still respond to water, especially liquid water). "The owners said... they had not let it sit in water." You can't trust this to be the case, sadly they might just be lying. But they they could simply be mistaken — how easy is it to miss one drop of water on a counter and for the board to then be placed on it? Also, did they clean it or not, if so how and just as importantly if not more so, how did they leave it to dry? [contd] – Graphus Nov 21 '19 at 7:28
  • Obviously there were glue-line failures too. Glue joints should never fail if done right, which may indicate that in at least in a few areas everything didn't go 100%. All too easy in a big thing like this with so many joints. I want to stress though that I don't believe this to be the cause — even if every glue joint were absolutely flawless a board can still crack, with the cracks exclusively going through the wood and just ignoring the joints as though they weren't there — it's just that this highlighted that there is an issue sometimes, which is something to bear in mind for the future. – Graphus Nov 21 '19 at 7:43
  • How fresh is that glue? I assume it PVC based adhesive. Uncured PVC glues do not last forever in the bottle, and this sort of stringiness can be related to glue that has reached a certain age, or has subjected to very low temperatures. – jdv Nov 21 '19 at 16:19
  • @jdv - less than six months. We go through about a gallon every 3-4 months. – Stephen Nov 21 '19 at 23:35
  • @GraphussupportsMonica - I think this may be related. Maybe. I found a cutoff from the pieces we put together and noticed that the edges are ever so slightly less wide than the middle. I'm thinking that maybe when this was put together we didn't really notice it being off that little bit, and the settling + expansion may have caused it to "pop". Granted, I don't even know if that's possible. But your explanation certainly has Occam's Razor behind it. [I think that's the right reference..] – Stephen Nov 21 '19 at 23:39
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This certainly appears to be a wood movement issue, if you look very closely at the first image, you can see the dark (walnut?) square block is not as wide as the maple behind it, yet the cut lines on the right side line up. Assuming the block sizes where the same when the butcher block was assembled the block that separated is slightly smaller.

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  • Good point. There's one more picture I didn't include though that shows that the maple actually cracked right there, and pushes it out of alignment. Let me see if I can edit my question with another photo.. – Stephen Nov 20 '19 at 21:38
  • Sorry for the late reply, I still thing this comes down to wood movement. Generally wood cracks because a glued piece expands and pulls part of the wood with it, or wood is trying to shrink and cant because it's firmly glued in place. In this case it may have been the latter the maple tried to shrink some and was unable too due to firm glueing and cracked. – user7993 Dec 2 '19 at 15:36
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We finally got the board back in hand. @GraphussupportsMonica's comments seem to ring true - this board is severely water damaged. It feels like sandpaper, all the oil and wax has been ripped out of it, and it has numerous joint failures. So, alas, it was no match for a dishwasher. We feel.. foolish.. for agreeing to replace without inspecting first, but it is what it is.

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    Sheesh. If you want a cutting board to put through a dishwasher, this is why Crom invented nylon cutting boards. – jdv Dec 19 '19 at 19:13

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