Need Advice: Prepping stock for a project

[Jeff Kerr]

I was fortunate enough to pick up some wide board cherry some time back and have decided to use it for a TV stand for SWMBO.

I have several boards that are 13" wide and was planning on planing and jointing them down for a 2 board glueup.

I mentioned this to a fellow woodworker and he advised against it thinking that I would have better long term results in ripping them down to 6 inch, then plane and Joint and glueup. This would have less planing because of natural cupping of wide boards and less chance for problems later.

Thoughts?

I was looking forward to having a nice wide 24" 2 board top.

[glenn bradley]

There seem to be 2 schools of thought; those that have had issues with wide board glue-ups and those that haven't. I'm sure the material and how it was dried has a great deal to do with the long term results. I have only used material purchased from my local lumber yard. I have used boards as wide as possible unless I need to size them for a balanced look so I would use 2 boards. Others will have different opinions. YMMV ;-)

[Prashun Patel]

Unless the boards are so beautifully figured that you don't want to risk interrupting them, I vote for ripping into 6" widths. With a thin kerf blade, after glue up, you will probably not even notice the interruption.

I would also do the rough milling now, so it can acclimate. Do the final milling when yr ready to glue.

[Michael MacDonald]

there have been other threads on this topic in the past... it is a question that has no consensus answer, apparently. Along with the topic of alternating the endgrain curve to avoid “compounded cupping”. (I just made that term up.) The issue of losing less material if you rip them is a pragmatic one, and I think there is no controversy over that... depends on how thick you need them and how much you have to work.

The issue of future cupping or twist is really the question. I would consider perhaps whether these are going to be similar open to air or similarly finished on each side. This will impact whether they evenly exchange moisture with the surrounding air. I can’t imagine that ripping 3/32 out and putting a film of glue between the halves will change that much in terms of cupping… if the whole thing was going to cup, then the two halves will cup… the only thing missing might be 1/10 of a degree of cupping potential from the immediate 1/2” of wood around the glue line, I would guess.

the presumption I am making is that the edge of a board--or the last 1/2" next to the glue line, does not cup... not sure why I have that thought in my head... may not be true... but it seems like cupping happens in the middle, not the edge.

Perhaps when you get down to gluing 1 x 3/4 strips together, cupping becomes impossible… but somewhere between 1-inch and six inches that advantage must all but disappear.

I am no expert… just some thoughts. Perhaps someone with knowledge of how the glue line helps with reducing cupping might chime in to correct me.

[Richard M. Wolfe]

I would make the two board wide panel, taking care that the two boards are jointed wwhere it takes no great amount of clamping to produce a seamless panel. Glue it, alternating clamps top and bottom, and let it sit for a while (time is up to you) to see if any cupping occurs. If you think its not wise to continue you can rip it then.

[John Thompson]

Ditto Richard... I would also go for the two board glue-up. If you have had them for awhile the boards should be acclimated to your shop already. First I would see what happens when you originally joint and plane. If they do not cup then they are not likely to cup latter. And as Richard states.. if they were to cup after you do glue them you can rip down the glue line and then rip to smaller widths. You have more options.

And.. if this is flat sawn as I suspect.. I would personally turn the open end of the growth rings all down in the glue up. Wood has a tendency to cup away from the pith so I turn growth rings down so any cup will happen in the center which can be pulled down easy. If you alternate you can get a ripple effect that makes life difficult and a eyesore if you have exposed end grain as in a table-top. Even an untrained eye will catch it immediately IMO.

If you turn all the open ends of growth rings up and you get a slight bow... you have to then pull the ends down which is double work and more complicated IMO compared to just the center going the opposite route.

Ain't all this fun? haha.. good luck!

[Lee Schierer]

Ripping a wide board and gluing the same edges with the faces as they were originally back together is a method used to remove the cupping from a board, it will not prevent cupping. If the wood is going to cup it will cup anyway. Alternating the direction of growth rings would not prevent cupping but would reduce the overall effect.

Surface your boards evenly on both sides and edges as much as possible. Take off half the material needed to size them and then stack and sticker them so they have air circulation and can't move. Let them set for at least a week. Check for cupping. If there is none, remove the second half of the material to be removed, again evenly from all surfaces and put them back into the stickering/clamping set up to dry for at least another week. If the boards still haven't cupped, then they probably won't. Build your project and apply equal amounts and types of finish to all sides.

I once saw a drop leaf table at George mason College that had a 30" drop leaf that was all one walnut board it was very flat after 100+ years.

[Rick Markham]

I personally would just glue it up. My thoughts on ripping a wide board when you don't need to, is that you are risking releasing some internal stresses inside the board, and having one of the smaller (interior boards) cup or warp. (don't know if there is any foundation for this) Besides, I like to use as wide of boards as possible in glue ups.

Remember back in the day, period furniture was made out of 18"+ boards, that stuff has been around centuries. They loved to hide endgrain, but my suspicion is any glue ups done was purely in regard to grain pattern, and alternating the direction of growth rings, was the least of their concerns. I've done both personally and neither one have I had a problem with later down the road.

I think ripping the board and then gluing it up in the same order isn't going to prevent any cupping it was going to do anyway.

[Prashun Patel]

Ripping may not prevent cupping after glue up. But will likely give you a thicker finished surface if any cupping exists before the glue up.

[Danny Hamsley]

Make sure the wood is perfectly dry for the area you intend to use it. If the moisture content is stable it will not cup. If the wood is not fully dry and in equilibrium with your environment, it can easily cup after you plane it as the wood dries further, setting up the stress that leads to cupping.

[Peter Quinn]

There are only two schools of though on this; the school to which I adhere and those idiots that do it wrong!:D How is that for clarity. (strictly kidding here)

Let me go out on a limb and state that I feel that people who rip a wide board just to reglue it from two smaller pieces and think they are actually doing something to control future cupping are smoking a harsh pipe! IME it is meaningless in all circumstances. 6X4=2X12 no mater how you slice the bread. You don't get more pizza by slicing it into more pieces.

But as Shawn notes, some boards come to you too cupped to flatten or plane relatively flat and reach your desired thickness, so rip and flatten is your only recourse, and in only those cases I prefer to split and reglue than loose the board completely. Otherwise I prefer to glue up as wide as possible and control cupping by using cleats or breadboards in the design. Most tops as thick as 1 1/2" will have some flex over 24" width and can be made flat enough for use.

As long as you use well dried stock, finish both sides, and don't involve your furniture in a water balloon fight, I doubt there will be any serious problems at 24" width. Remember to allow for wood movement in your attachment method to avoid splitting.