View Full Version : thinning a soundboard

03-27-2009, 08:14 PM
hi all just require a bit of advice

i've been thinning down a recycled floorboard to use as a soundboard and got it down to around 4mm thick, but its not exactly even, is there any way to flatten it to 2 or 3mm.

just wondering how every body else gets their soundboards to the right thickness.


p.s. so far i've been using a plane and sandpaper, but its not exactly even

03-28-2009, 02:02 AM

I don't know if this is what they use for guitar woord, but here is what I do for planning other woods when I dont have acces to a real sander :

-I buy or make some spacers (in you cas, buying a sheet of 3mm MDF should be fine)
-I lay the spacers on the table on each side of the piece I want to correct
-I glue some sanding paper on a large sheet of flat plywood
-I sand until the sandpaper barely touche the flatened paper because the plywood touches the MDF

Final thickness of the sanded piece is spacer height minus sandpaper thickness.

Of course, you have to work on a flat workbench :)

03-28-2009, 09:12 PM
yeah i was coming to that conclusion, that will have to be the way forward. let you know how it goes



03-29-2009, 10:21 AM
Here is a trick that we carved top builders use, provided you have access to a drill press. Sand one side of the soundboard flat. Chuck a small (1/8" or so) bit in the drill press. Set the drill press stop to the desired thickness when you lower the spindle, in other words the bit stops at the desired thickness above the drill press table. Drill a number of holes in the side of the top you wish to plane/sand. Plane/sand until the holes just disappear. Works really well if you don't have a thickness caliper.


03-29-2009, 10:43 AM
Good trick :) I have also used a similar one, but :

-the press is replaced by a temporary custom made fixed height plywood bridge
-the drill is replaced by a router
-the bit is a planning bit (I'm sorry if this is not proper name in english :))

You need to have a router and buy the bit, of course :)


03-30-2009, 02:44 PM
just saw this


03-31-2009, 07:38 AM
If you have access to a drill press.....the Wagner Safety Planer works great. I think StewMac sells them now. Tops, necks, headstocks, fingerboards are all easy to plane down with this arm saver. Just leave a couple thousandths extra to sand out the swirly marks