Built a walnut cabinet for a client in Denver last month and the finish is already showing hairline cracks

Client wanted a custom media console for their living room. I used 4/4 black walnut with a simple shaker style door. Finished it with three coats of a water based poly, sanding between each. The house is new construction, so the air is super dry. I warned them to use a humidifier. Checked in last week and the panel on the front has these tiny cracks running with the grain. Not deep, but you can see them in the light. I think the wood moved more than the finish could handle. Should I have used an oil based finish instead for more flexibility? What's your fix for something like this?

2 comments

2 Comments

the_viola1mo ago

Three coats of water based poly is pretty rigid for a big solid wood panel in a dry house. Did you seal the back and edges of that door panel the same as the front, or just finish the show faces?

quinn_kim451mo ago

Yeah, that's a solid point from @the_viola. My buddy learned this the hard way. He built a beautiful oak door for his office and only sealed the front. He used three coats of poly on the show face, just like you said. A year later, the unsealed back sucked up all the winter air and the panel cupped like a potato chip. Had to take the whole thing apart to sand and seal the back. Now he treats every side the same, no matter what.