Grit Progression for Sanding Doors on the Widebelt

Which grits to use depends on how much thickness you need to remove. July 9, 2009

I made a couple of custom cherry interior doors with flat panels. I would like to run them through my widebelt sander. What would be the sanding sequence as far as grit sizes? I purchased the sander in the spring and have only used it for inline sanding. This will be the first time I have sanded any doors.

Forum Responses
(Architectural Woodworking Forum)
From contributor S:
It depends on how much you need to remove. If more than a 1/4" then I'd start with 80. The last 1/8" or so I'd switch to 120 or a little higher. You can use 120 all the way through, but I'd rather try and save it a little. You’re going to have to sand the rails by hand anyway because of cross grain scratches.

From contributor K:
I like to sand all my faceframes and doors down with 80 then 150 then 220 or 240 when I have cross grain sanding to do after. It's much faster to sand out the 220 or 240 cross grain scratches with the 180 random orbital than it is to sand 150 or 180 cross grain scratches. It also means you will spend less for sanding disks.

From the original questioner:
This is the first time I've tried doing any cross grain sanding and didn't want to mess these doors up.

From contributor G:
As mentioned it depends on how much you need to remove. You can remove about .015" per pass with 80g and .010" with 120g. If you need to remove upwards of 1/4" (the doors shouldn't be that much too thick to start with) you might want to use 60g which can remove .025-.030" per pass. So the sequence would be 60 80 120 150 180 220g skipping 60g if you do not need to remove massive amounts of thickness. Sand to close to the final thickness with the 60 or 80g. From there you only need to remove the scratches from the previous grits with the next finer grit removing only about .005" per pass with 150 and finer. As contributor K said sand to 220g or so to make random orbit cross grain removal easier. Don't skip grits. It only costs more time in the long run.