[Herb Stoops]

I do it like Don said . Only I saw it all the way through and joint the edge and re glue it. Then if it needs more in a different spot I do it again til it lays flat, the grain matches so the saw cut don't show. Some times I rip them and turn them end for end. Then after they are glued up I run them through the planer or drum sander to finish them. I find that less thickness is lost by doing this.

Herb

 

[Herb Stoops]

Herb; if you flip end for end don't you create an issue with grain direction when it comes to the planing? Why not just flip the piece over top to bottom, assuming the quality is the same for both sides (no knots etc.)?
You'd also counter the warp effect by flipping over.

Your suggestion sounds good to me. If I flip end to end,I dress it down with the drum sander. That is the last resort because when the finish goes on the grain reflects the finish dark and light.

I can flatten most boards by just ripping and reglueing as many times as it takes.

One time I had a PU load of reject Elm 1" rough sawn boards from the mill given to me. They were straight on the edges but the hump was between the ends ,like skis. I ended up ripping them into 2 1/2" wide strips and then planing them. and nestling them (spooning them) together making a 2 1/2" thick plank ,then resawing them into (2) 1" thick boards.

Herb