Refinish A Cutting Board

So you have an cutting board that is showing its wear with cut marks and stains.

To refinish you will need to bring the wood to a flat state without cut marks.  Use an Orbital Sander (available at Lowes, Harbor Freight, etc.   Look for the tag of orbital using round sanding discs.
You will need multiple grades of sandpaper.  I typically start with 80 grit, then move on to 120 grit, then to 220 grit, and maybe to 320 grit.  This is called working the grits.   80 grit sandpaper is rough and 320 grit is almost paper smooth.  

When working the grits you will need to spend some time and work the entire board.  Avoid gouging an area.  Use a rubber sandpaper cleaner to clear dust off your sandpaper.   Vacuum the board frequently and rub off any dust with cloth or shop towels. 

Water bursting is done on the final step.  This involves spraying the board with water, then letting it dry, then re-sand with the last grit.  This step opens the fibers of the wood to get a smoother finish.   You can do it between every grit but I find it sufficient to do 1 or 2 grits.

Our goal with above it so have a smooth board, remove knife marks, and to remove any old finish. 

Time to refinish now.   I use a product from Tennessee based company called "The Real Milk Paint Company".   You can find a similar product at Lowes or similar store called Walrus Oil.  What ever product you use, check for food safe contact.

Rub the oil or paste into the board and let it sit at least 15 minutes.   Wipe the oil off and re-apply.    With the liquid product, I go to 320 grit then apply... with paste product, I go to 220 grit and apply.   Give it a few days to dry before use.

Also there are many products to use labeled cutting board oil, tung oil, etc.  AVOID using varnish or polyurethane. 

If you have a warp in the board, that will likely take a wood worker to restore if that is even possible.   A trick for a small warp is to apply rubber feet to one side of the board if the warp is not severe.