Planer/Jointer questions--how "flat" to make a board?

[MBeckmann]

Hi,
I recently got back into woodworking (after taking nearly 20 years off!), and am now getting geared up with equipment and a shop; and have just tackled my first major project--a cherry bookcase.
My question has to do with how flat and true does a board need to be. I bought some rough-cut lumber, and face-jointed with my planer, using shims (don't have a jointer yet). The board will be a vertical leg on the bookcase--dimensions of the leg are 3/4" x 3" x 72". When laid face-down on a flat workbench, the ends of the board touch the benchtop, but there is a very slight gap in the middle, less than 1/16". Will this be noticeable/objectionable? Is there a rule of thumb for tolerance for twist/cup/warp? I worked on this board for nearly an hour, and can't get it any truer--my feeling is that no one will be able to notice 1/16" over a 6-foot span; but it may screw up my joints.
My next purchase may be a jointer--but what can I expect from a jointer? For instance--will a jointer completely eliminate my current problem?
Any comments would be greatly appreciated! Thanks in advance for your help,
Mike in Wisconsin

[MikeMcCoy]

If you are going to have a back on the piece, you can probably live with that and use the back to line things up. I have a jointer but only use it primarily for edge joints. Every cupped/crooked piece gets dealt with by hand planes and it's just about as fast and a whole lot quieter.

[LCHIEN]

There's straight and there's flat.

if the board is not straight, then you will have problems with you bookcase carcass.

If its not flat, then in all likelihood when you put the shelf boards in rabbets in the wide panels then the side panels will be pulled quite straight and held that way, if they only have a 1/16th inch out-of flat end-to end. OTOH, if it has a 1/16th inch cup, then you may well have problems.

In any case, if it has 1/16th warp, cup, or twist then you will end up taking 1/16th off both faces and end up with a board 1/8th thinner than you started, if you want to make it truly flat. (and it might not stay that way when the humidity changes).

[cabinetman]

I agree with Mike on the use of hand planes. The vertical inconsistency may be corrected with the joinery, which may straighten out the curves. Out of flat can be corrected with hand planes. Did you acclimate your lumber before machining?
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[MBeckmann]

Thanks for the help, guys, looks like I'll need to purchase a few more hand planes (just have one, an old hand-me-down block plane from Dad). It sounds like a power jointer will probably not prevent this problem--I'll still need to hand-plane to get that level of perfection? If so--you've just saved me some money and a LOT of shop space!
And no, I don't really acclimate the wood--I just have it inside, in the basement; the bookcase will eventually move upstairs, into the kitchen, where of course it is slightly warmer.

[MikeMcCoy]

Thanks for the help, guys, looks like I'll need to purchase a few more hand planes (just have one, an old hand-me-down block plane from Dad). It sounds like a power jointer will probably not prevent this problem--I'll still need to hand-plane to get that level of perfection? If so--you've just saved me some money and a LOT of shop space!
And no, I don't really acclimate the wood--I just have it inside, in the basement; the bookcase will eventually move upstairs, into the kitchen, where of course it is slightly warmer.

I don't see planes for sell much on BT3 Central but I have gotten some really good buys on user planes over at Woodnet. Occasionally they appear in the Swap and Sell Forum but more often than not, they only get posted in the Handtool Forum. Of course if you don't easily get sticker shock, there's always a Lie-Neilson on the horizon.

[BigguyZ]

You know, I've been more and more intersted in hand planes for these types of tasks, but how do you accurately flatten a wide board with something only 2 1/2" wide? It seems to me that it'd be a whole lot of work to do. Especially if you want to take the overall thickness down.

I'm going to be in the market for a planer as well, but hand planes interest me as a "tkae your time and enjoy the process" level.

[JR]

Any comments would be greatly appreciated!

Welcome to the forum, Mike!

I really don't think you're going to have any problems with this board. Assuming you're going to have joints top, middle, and bottom, that 1/16" is going to disappear during assembly.

JR

[MikeMcCoy]

You know, I've been more and more intersted in hand planes for these types of tasks, but how do you accurately flatten a wide board with something only 2 1/2" wide? It seems to me that it'd be a whole lot of work to do. Especially if you want to take the overall thickness down.

I'm going to be in the market for a planer as well, but hand planes interest me as a "tkae your time and enjoy the process" level.

Warning first of all that hand planes are almost as slippery a slope as the one that a lathe sits on. With that said, most hand plane users have several that range from smaller block planes up through the large beasts called jointer planes. It depends on what kind and how rough your stock is. I'm going to post a couple of links with a ton of info.

http://www.supertool.com/StanleyBG/stan0a.html

http://www.cianperez.com/Wood/WoodDo...DEX_How_To.htm

[Workman]

Not being an engineer and relatively new to using handplanes, I can only say in reply to the how do they work question that (1) they do work (2) a true straightedge helps you know this (3) they work best going from jointer, try, or fore planes (#6, 7, or 8) down to jack (#5) and then to smooth planes (#2, 3, or 4). The long planes take out the high hills and then on down. The planes seem to find the high spots automatically. I am sure Larry or some of the engineer types can explain how this works both along and across the board. But of course, plane with the grain. I like to wind up the process with a scraper (I use an old Stanley #80). I also have found that I should allow an extra 1/16" after jointing and planing with the electric tools for the hand planing to final dimension.