This is on the back side of an end grain cutting board that I'm almost finished with. I vacuumed it off this morning, then thoroughly cleaned it with mineral spirits and set it outside to dry. Not all that warm out today, so the board got down to probably 45-50 degrees over the coarse of several hours. I brought it inside, then used the branding iron on it. I had to hit it twice with the iron, as the transfer wasn't complete after the first try (which also explains why there's a bit of a ghost image since I didn't get it perfectly aligned the second time).
After lifting the branding iron off the second time, I heard a small pop. I looked down and saw the larger of the two cracks that runs through the "A" in Jonathan, then the left wing, and up through "RA" in "CRAFTED". A few seconds later, I heard another little popping sound and looked again to see a smaller, narrower crack that's hard to see in the photo. It runs through the right wing and down through one of the "E"s in my last name.
I haven't had this happen before, and I'm thinking it was because of the sudden temperature fluctuation within the wood, especially since it went down through the end grain, causing the wood to dry out ever so slightly and crack. This is all kiln-dried wood, by the way.
I believe these cracks to be fairly shallow, but I don't want them to get any worse. At this point, they're only on the underside of the board, which I'm not too concerned about, but I don't want them getting any bigger and going all the way through to the front of the board, which is about 2-1/8" thick.
I plan on finishing this board with mineral oil and wax. I am wondering if I should try to use a little thin CA glue in the cracks or not? That will create the issue of the mineral oil not taking there, and causing a color variation. And if I apply the mineral oil first, I'm thinking that trying to apply CA glue after that won't be effective.
Any thoughts on this predicament?