Board Tolerance After Face Jointing

I've just run a 4' x 6" x 4/4 walnut board over my new (and first) jointer, and I seem to be having trouble getting the board's face completely flat. There's still a very slight concavity, rising to a height of about 1/64" in the center. I'm concerned that the curve might be caused by either (a) despite trying to have a very light touch, applying too much pressure during jointing, thus flattening out the natural concavity so that the jointer can't correct it; or (b) having the knives too high relative to the outfeed table. Before I investigate these matters further, am I wasting my time trying to get rid of this amount of curvature? Is a tolerance of, say, within 0.008" a reasonable level to shoot for?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sounds more like a pressing problem than a blade/table. Those kind make tapers or snipes.
I only guide on the infeed table, pushing down and through on the out when taking a full pass. To allow for the possibility of outfeed droop, which might produce what you have, I feed stepwise within a foot after the knives.
To clear up concavity of a minor nature, start jointing near one end (13-1/4 of length) to flatten, before running full length. In this case, hold down to reference infeed. If the concavity's bad, joint one end, then the other until it looks close, then full length.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.