I've recently started making chopping boards and I'm having a tough time getting them to stay flat. I use a router and jig to plane them, and they seem flat when I check them against my kitchen counter. However, after sanding them—working my way up to 600 grit—they warp and no longer lie flat. Is there a trick to getting a flat chopping board after the sanding and sealing process? I really need some help!
3 Answers
Sanding up to 600 grit can create too much friction on one side, which isn’t really necessary. Instead, balance your sanding by doing both sides with each grit and stop at around 220. A handy trick is to scribble some pencil lines on the board; when they disappear, you've sanded enough!
It's crucial to use a flat reference, so try checking against your table saw surface instead of your kitchen counter, which might not be perfectly flat. Also, make sure your wood is properly dried (aim for 7-10% moisture content). Lastly, ensure you treat both sides of the board equally during sanding. Good luck!
Do you live in a humid area? I sometimes have this issue in the summer. I let my boards acclimate for at least 30 days before working on them. If it's really humid, I let the glued board dry inside for a day before sanding. Seems like you might need to ensure they're fully dry before cutting or sanding, so check the moisture levels!
Thanks for the tip! The drying process makes sense, but it’s still frustrating that they warp after sanding.