milling cupped boards

[Brad McCollum]

I have a pile of rough sawn, kiln dried hickory that is cupped. I am thinking I should join one face and one edge before planing and ripping. I don't have a lot of experience with rough sawn timber but this stuff is too pretty to pass up. The end result is to be a dinning table. Should I start concave side down on the joiner then go to the planer? The boards were flat sawn about 6/4 thick. The worst cup is about 3/8 on boards 6" wide. The goal is to end up with 4" material 3/4 thick.
Thanks in advance for any help you can give.

[Mel Fulks]

I would ignore the cup while at the jointer and base my decision on bow. See earlier posts on removing bow for thorough spirited debate.

[Charles Lent]

The first thing that you need to do is to determine if the board will be thick enough to use after you have flattened both sides with the joiner and planer. A significantly bowed 5/4 rough sawn board may not even get you a 3/4 thick board after it is milled. If there is any twist it will also reduce the thickness of the end result. Then you should also consider that a cupped board will likely cup or bow again after you have made your table with it. I know you like the grain patterns, but maybe you should try to find a use for it that does not require long stock that remains very flat throughout it's life, as is required for a table top.

Charley

[johnny means]

My first step would be ripping on the bandsaw, to 4.5"

[Sam Murdoch]

The answer to your basic question is - YES - but all the above needs to be considered too.

[Jeff Duncan]

I won't tell you what you should do.....instead I'll tell you what I would do

I would run all my boards with the cup facing up, (or concave side up), generally speaking if the cup is up so will be the bow. (This is a bit harder to do if your not experienced on the jointer, but again, it's that way I would do it). I'd take of at least an eighth in each pass and hope to get it flat enough in 2 passes. Then I'd run them through the planer to clean up the other side. Once that side is clean a light pass on the side that was initially faced on the jointer. At this point if your stock was reasonably straight to begin with you would now have something in the neighborhood of 1-1/8" - 1-1/4" of thickness.

I would let the wood sit for several days and see what it does. If some pieces move a lot, I wouldn't use them. If pieces move a bit you still have room to repeat the flattening process. FWIW I would never go to 3/4" on a table. IMO that's way to thin and your almost certainly going to have warp problems. The thicker the better so I'd keep it 1" plus....but that's just me. I also wouldn't rip them down to 4"...smaller pieces make it look like a factory table.

good luck,
JeffD

[J.R. Rutter]

I would approach this more or less as Jeff outlined. The main thing that I will point out is that i would consider how you plan to flatten after gluing up. You may not need to start with absolutely flat boards as long as they are mostly uniform thickness. You can try to hold some boards in tension with each other to balance the assembly and flatten with handplanes, or find a shop with a widebelt sander nearby.

[glenn bradley]

Reducing the dimension on the bandsaw reduces the impact of the curve prior to flattening surfaces. Several good articles discuss many flaws and how to deal with them here: http://tinyurl.com/8woph87

Hmm, looks like you need to subscribe to view the videos and articles. Sorry about that. I am a subscriber but, have no other association with Fine Woodworking Online. For your purposes, I would probably consider the 30 day trial just to watch and read up on milling.

[Matt Day]

Not only rip the boards, but I would also cut them to length +6" or so. The closer the boards are to final length and width, the less impact cup and bow will have at the joiner/planer.

[Paul Murphy]

Getting the thickest and widest piece from your stock is a balancing act of competing goals. The longer/wider pieces must come from the flattest rough stock. Sometimes you just have to set some boards aside for other uses if they cannot yield the desired width/length/thickness.

Unless your stock is very flat or well above finished thickness you should mark your parts from areas of the board that can realistically yield your desired dimensions, and cut to rough size+ before you joint and then plane. The small/narrow parts can come from boards with more cup/bow/crook while still yielding your desired finished dimension.

If your table is 6’ long, then cut your rough 6+’ blanks from the straightest/flattest part of the board. Sometimes your concave section is toward the middle…if so then perhaps joint that face only enough to provide full thickness near the edge for planer support and gluing. The face with some remaining rough concave area may be acceptable to you/your customer if it is on the underside of the table and within the apron. This compromise may enable your desired thickness and width at the visible face/edge. I like wide boards, so this is a compromise I have accepted at times.

For an average size dining table I often use 7/8” thickness at the edge, and a very large table might use 1” thickness. That is often really just a visual decision, and all part of the tradeoff made at the beginning of every project.

I agree with many others that you may want your table-top boards maximum practical width rather than 4”. Just my opinion based on what I find attractive.

[Robert LaPlaca]

I won't tell you what you should do.....instead I'll tell you what I would do

I would run all my boards with the cup facing up, (or concave side up), generally speaking if the cup is up so will be the bow. (This is a bit harder to do if your not experienced on the jointer, but again, it's that way I would do it). I'd take of at least an eighth in each pass and hope to get it flat enough in 2 passes. Then I'd run them through the planer to clean up the other side. Once that side is clean a light pass on the side that was initially faced on the jointer. At this point if your stock was reasonably straight to begin with you would now have something in the neighborhood of 1-1/8" - 1-1/4" of thickness.

I would let the wood sit for several days and see what it does. If some pieces move a lot, I wouldn't use them. If pieces move a bit you still have room to repeat the flattening process. FWIW I would never go to 3/4" on a table. IMO that's way to thin and your almost certainly going to have warp problems. The thicker the better so I'd keep it 1" plus....but that's just me. I also wouldn't rip them down to 4"...smaller pieces make it look like a factory table.

good luck,
JeffD

I totally agree with Jeff, just to reiterate after getting the 6/4 flat on both sides, I take the stock to 1/8" over final thickness, I would sticker it for a few days (I usually do a week) so the air can get to both sides. After the resting process has completed, you have a fairly good idea what boards are going to be squirrelly, I would reface one side and continue to the final thickness.. It's also best to get them close to the final length and width +1/4~3/8" during the initial flatting process. Good luck

PS: 6/4 is pretty thick stock for a 3/4" net, unless the rough stock is absolutely terrible or you need extremely long and/or wide widths 4/4 or 5/4 should do the job..

[Andrew Joiner]

I hate to complicate this more, but I select for grain first, then cut to rough length. I flatten on a planer sled. I take as little wood off as needed to get straight and flat. The bottom of the table can be ugly as long as it's smooth. I straight line rip on the table saw with another sled. With 6/4 you ought to be able to get a top thicker than 3/4".

This is why sheet goods are so common. Selecting,milling and gluing up a solid top is a real craft.