silly planing question

[Bob Parker]

I just need some reassurance before i do this... I've glued up a panel of walnut boards for a coffee table and need to plane it flat now. It is "economy walnut" which means there are a few knots and other character. Would it be ok to plane with reckless abandon diagonally to flatten the board and then expect to get out all the plane marks and tearout by using a smoothing plane and finishing with a card scraper? i'm working with someone elses wood so excuse my timidness.

[Johnny Kleso]

You cant plane reckless but you can plane and watch whats happening..

First thing is use a straight edge and mark your high spots and knock them down..

Then try planing diagonally but be aware if you start pulling big chucks out..

[Frank Drew]

Bob,

A scrub plane (with a slightly crowned edge) is a good tool to flatten wood without so much danger of tearout, but you'll have a lot of cleanup afterwards so only use one if you've got to remove a lot of wood to flatten the panel. If the panel is already fairly flat, you should be able to get by with a jack or jointer plane followed by a smoother (or do the whole job with a jack plane, finishing up with a freshly sharpened blade and a light cut).

[David Keller NC]

Bob - You're going to have to be cautious about this if the panel was made of already-surfaced 3/4" stock. Moreover, you may find that the panel wasn't glued up with planing in mind - in other words, the grain reverses direction in adjacent boards.

Were I confronted with this situation, and the table top is pretty flat but just has machine marks, I'd use a scraper plane to do this job (I use a Lie-Nielsen #112 Stanley copy, but any of the old Stanleys would work well). The advantage is almost no risk of taking a huge chunk out of the top where the grain reverses around a knot, which is a distinct possibility with an aggressive plane.

If the top is not flat, and is cupped or bowed no more than about 1/4", I'd flatten it by the moisture adsorption method, then fix it to the table aprons before final smoothing. The way to do this is to put a moist (not wet!) towel on the concave side of the top, and use a hairdryer on the "low" setting to dry out the convex side a bit. The moisture will expand the wood on the side that's cupped, and the hairdryer will dry out and slightly shrink the side that's convex. If you monitor it carefully, you can catch the point where the top is pretty much flat, fix it to the aprons, and allow it to come to moisture equilibrium with your shop again.

It doesn't happen often, but note that there's a small risk of the top cracking when it comes back to moisture equilibrium. In my experience, the risk is small if the top's only out by a little (the previously mentioned 1/4"), and the top is fixed to the apron with moveable joints so that it "floats".

[Mark Singer]

David is correct and it is a very common issue that when laying up boards the direction for planing is not considered. So as you cross boards you are planing "against" the grain. If you glue up for appearance and don't check the pith side of the board and arrange them you will be faced with this.