Flattening a 22" wide Pine Plank

[Doug Shepard]

I get home today to find my uncle had dropped off a 5/4 22" wide x 40"-ish pine board and wants to know if I can run it through my Performax 16/32 to flatten it. Apparently a friend of his found this behind a wall during a house demolition and he and my uncle want to make a coffee table out of it for a vacation cabin. I take a block plane to the end to see what's going on, and I've got doubts this thing wont just cup again if I try to sand it flat plus it's going to put the thickness around 3/4". It's a pretty non-descript looking piece of wood and I personally wouldn't bother with it but they want to try. The ONLY thing going for it is the thickness and the fact that it's a single plank. I suggested they rip, alternate flip, and re-glue but they want to keep it one piece. So my next thought is that maybe if they can moisten one side, sticker it, and weight it down that they may be able to pull enough cup out that table-top fasteners cinched down to table aprons could hold this flat?? I think this might work, but which side do they want to moisten - bark side or center side? And how long should they let it dry afterwards?
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Thanks in advance.

[Jim DeLaney]

I seriously doubt that moistening it will work. It's probably time to break out the scrub plane(s) and get yourself a good upper body workout.

Actually, being pine, it ought to hog off pretty quickly. Probably only take half an hour or so to flatten.

BTW - are you sure your drawing is correct? Boards usually cup in the other direction.

[Doug Shepard]

Yeah - the growth rings are curved in the opposite direction of the cup. I thought about the scrub plane too, but was hoping to put as much of this problem as possible in my uncle's hands, and not mine. Handtools aren't really his thing so I'd have to do it. Got enough stuff going on right now with trying to get my DC ducting in but handplanes is one other possibility.

[Jim Becker]

3/16" on a 22" wide board isn't much. If you design the support structure of the table well and use good mounting methods that take into account wood movement, the board should flatten out fine just by the mechanical fastening. If they like the style, they could clamp the board flat and machine for bread-board ends that would further assist with keeping it flat without reducing thickness.

All this IMHO, of course...I have not seen the board...assuming it's real... ;)

[Ron Brese]

Being pine it is going to pitch up some sandpaper pretty good if you run it thru the performax. In fact you'll probably have to clean the wrap several times during the process and then most likely scrap that wrapping when you're done. Relatives have a way of ignoring cost issues when they ask for a favor. Been there, done that, had to replace the sanding wrap out of my own pocket.

Ron Brese

[Doug Shepard]

...
All this IMHO, of course...I have not seen the board...assuming it's real... ;)

Oh it's real allright - a real PITA:mad: . I tried to take a pic last night to show the growth rings after I planed it, but my camera's macro abilities aren't that good. Right now it's fairly dirty. I'd have to take the ROS to it just to get the dirt and grit off before I do much else to it. Maybe once it's cleaned up some, I can get a half decent pic.

[David Weaver]

Scrub plane - I agree. I just got two scrubs for my first scrub planes a couple of weeks ago. I can't tell from your response whether or not you have one, but if you don't and you do get one, you'll be astounded by how fast they can remove stock, and how easy they are to push.

If you're forced to level it with a bench plane, at least it's pine. There's probably a 10 to 1 difference in your tiredness after using a bench plane vs. a scrub plane.

Apologies for the "overexcitedness" about scrubs - I just feel like a dunce for not getting one sooner after seeing how useful they are. I got a LN and LV version, knowing there's a huge difference in totes (WW buddy has hands much larger than mine). He purchased the LV from me, and i'm left with the LN, but both are nice and work well. A stanely 40 1/2 would be fine, too, and they can be gotten much more cheaply.

Oh, and you can scrub plane mildy dirty boards without making them perfect - something I wouldn't do with a high quality finely tuned bench plane.

[Doug Shepard]

I do have a scrub (LV) and would probably put either (or both) my LV BU Jointer or LN LA Jack to work after that. Good excuse to practice my handtool technique, but it's pine (blech) - almost hate to touch my nice tools to the stuff:D

[Ron Brese]

You'll certainly be cleaning the pitch off those plans when you're done. When I'm asked to quote a piece of furniture in pine folks are amazed when it is not cheaper than with quality hardwoods. I then explain to them that I will probably have an entire day or more in cleaning off the pitch from every machine that I use on the stuff. Some things are more appropriate in pine but it does have it's own set of expenses.

Ron Brese

[David Weaver]

I do have a scrub (LV) and would probably put either (or both) my LV BU Jointer or LN LA Jack to work after that. Good excuse to practice my handtool technique, but it's pine (blech) - almost hate to touch my nice tools to the stuff:D

I've never scrubbed pine - never had any good enough to plane and be worth the effort of cleaning the pitch and sap. Let us know how the edges of the wood hold up if you scrub it.

[Greg Robbins]

Doug,

Since you live in Michigan and there's a lot of dew on the grass in the morning and the weather's pretty good right now, try this. Take the piece out in the morning and lay it in the grass with the cupped side down. Let the sun beat on it for a few hours and see what happens. If that doesn't help, just like Jim says, 3/16" isn't that much and it wouldn't be difficult to pull it down with the proper supports.

[David N. Williams]

Hmmm... most cupping I've seen is towards the outside of the tree. This happens when the wood Moisture Content goes down. It would cup toward the inside if the wood MC increases, though, so I suppose it depends on your climate. Anyhoo...

I've got some old baseboards that warped while I was stripping them... Here's how I straightened 'em out good enough to hang. The nails keep 'em straight, now.

Try wetting the cupped side, lay a sheet of Saran Wrap on it to keep the water in, and set it across some sawhorses in the sun. Might take a day or two. Add 3 or 4 cauls across the width if its not straight after a day and try again. Less prone to split than if you put them on first thing.

When its straight enough, strip off the plastic and let it dry in the cauls for a couple of days. In fact, keep it in the cauls while you're not working on it. Securing it to the aprons with pocket screws and screwing a few battens to the underside will help keep it flat. Might save cleaning those tools!

Good luck.

[Doug Shepard]

Well I decided to dive in with the hand planes this evening as I had an extra hour or so to kill. Took the LV scrub to it and worked the hump out in the middle then had to remove some more about 2/3rds of the width as one side still curved downward more than the other.
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Then decided to put the Anant #8 (not one of the newer Kamal versions) to work. It's not a great plane but works well enough and it's longer and heavier than my LV BU jointer and I thought that might help some with this. So now I've got one side flat (but not smooth) and had to stop as it was getting too dark. I'll tackle the other side tomorrow then smooth both out.
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Really gotta do something soon about getting a real workbench.

[Cliff Rohrabacher]

Let them use your scrub plane in your shop and teach 'em how to do it. You convey a good thing and they get a clue about what it is they requested.

[Doyle Alley]

Maybe you experts could answer this. Once he gets it flattened, what is to prevent it from warping again? Wouldn't the flat-sawn nature of the wood still tend to make it cup?

I was thinking the best way to tackle this would be to rip it into 4" wide pieces, run them through the jointer/planer to flatten them, and glue them up with the rings in opposing directions.

[Paul Simmel]

Doyle,

>>> Once he gets it flattened, what is to prevent it from warping again?

I’m not an expert, I can only tell you what I know from experience.

When a piece is sliced off from the trunk it becomes an independent piece of wood. It has been “released” from the whole. So-called stresses pull the piece every which way now that it is independent. Stickering helps keep the board “flat”, but after drying, that board still has innate “will” to move. And it will move.

Once it has done its thing and moved, twisted, cupped.. in Doug’s case for a long time:

>>> a friend of his found this behind a wall during a house demolition

It has more or less “stabilized”. It has become “itself”, and no longer a piece of the whole tree.

3/16” cup over 22” is not a lot. To alter the board “a little” will probably not affect it much now.

As to your ripping suggestion, and in keeping with the OP intent to maintain a rather rare 22” single board (which has “stabilized”), to rip-and-flip will make the piece look like any other glued up panel whose grain doesn’t flow as one piece.

Because Doug said, “It's a pretty non-descript looking piece of wood”, before I saw that Doug decided to get an upper-body work out, I was going to suggest that he indeed rip his piece a number of times with a thin kerf, ever so slightly face-joint and plane, but glue it back together as the piece cam apart, grain matching. That would have removed the cup and retained the look of a single, 22” plank and would have probably allowed him to keep the piece thicker as well.

Hand planing it as he is now, will make it flatter than it was, but he will be loosing a lot more thickness.

-=-=-=-

Doug, my remarks to Doyle is in no way a criticism of your efforts to simply get that thing out of your shop! <smile>

[Doug Shepard]

I originally suggested that they do the rip/flip/re-glue thing, but couldn't sell it. Shame, because that would have put the whole project in my uncle's shop.:D Anyway, I also agree with you Paul - this board has been around for a long time and should be fairly stable although I too was also concerned some about it re-cupping. Cant get any pics to show the rings but the center 8-10" has the growth rings almost dead parallel to the top/bottom surfaces. Nowhere do they approach vertical (like quarter-sawn). But this looks like it was cut from about the outer 1/3 of the tree so had to be quite a big sucker. So I'm guessing this thing may have been cut as much as 100 years (or more) ago. I think the house it came out of was very old. When this is done, I think I'll be looking at a final thickness of around 1"+
Will post some pics and measurement once I get this done (and outta here!) Did I mention how sore my arms are?:D

[Doug Shepard]

Well it's finally outta here!:) Now I can get some more DC duct work done this weekend.

Started off setting the marking gauge to the thinnest spot from flattening the first side. Marked a line on all 4 edges then darkened it with a pencil and scrubbed all four edges to the line. Then scrubbed some more to connect all 4 edges into the same plane, checking along the way with a straightedge. Here's side 2 after flattening.
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Then pulled out the Anant again to get the scrub scallops out and fine-tune the flatness. These things get trashed a lot, but for $90 I think they do a pretty fair job. My biggest complaint is that the adjuster tends to work free too much and you have to keep putting a 1/4 turn or so on it to keep some positive pressure on it so it keeps the same cut setting.
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I dont have any camber on the #8 blade though so had plane ridges on both sides after flattening. So I used the LN LA Jack to improve things (mine has a tiny bit of blade camber).
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Still had some minor ridges, but MY job was to flatten it. My uncle can smooth it out and make it purty.:D I called him up, and told him to come pick it up as I had it done (LIE). Got the Stanley #80 ready and put him to work when he arrived. 30 minutes later any remaining ridges were gone.
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Then I handed him the broom and dustpan while I commenced to wiping the pitch off my planes with acetone. He was still sweeping up when I got that done.:D Final thickness ended up at something like 31/32".

[David Eisan]

I have flattened and surfaced similar boards on my drum sander.

Bash together a torsion box a little bigger than the boar out of any thin sheet good that has been sitting in your shop too long. I like quick and dirty with melamine leftovers and a narrow crown stapler.

Attach a fence at the back of the torsion box. With the crown up, use hot melt glue and some shims secure the board with no rocking.

Start with 36 grit as you will never load 36 grit, your 16x32 should have come with one strip. Surface the crown up side, rinse, flip, repeate. Work your way through the grits and you will have a nice flat board.

I have done this a number of times with special boards too wide for my jointer/planer.

Thanks,

David.

[Ted Owen]

so I know this doesn't help you. But for future reference--I've addressed the same problem in Maple by wetting the concave surface and running an clothes steam iron down the piece until it cupped slightly the opposite direction. The iron does not touch the wood, it rides on a wet dish rag. Even shot some steam in there where the piece seemed cantankerous.

Then weighted it down, and it flattened as it dried. Happened to guess close enough the first time on how much to cup the opposite direction to end up with a sufficiently flat piece.

Stayed straight to this day AFAIK.

Best, Ted

[Doug Shepard]

Sorry I didn't see the thread sooner...
...
Best, Ted

You tell me this AFTER I so carefully worked on my Popeye forearms?:mad: :mad: If I could raise my arms above my waist, I'd throttle you:D

I'm definitely bookmarking this iron tip. Sounds a lot easier. Thanks.

[Ted Owen]

I'll alert the local police to keep an eye out for Michigan license plates. :D

Tage Frid showed that ironing tip in his FWW series way back when. Works great. But you look kind of silly ironing wood through a wet cloth.

One more thing--I've heard you may get some resin on the iron from some species. But I never had any problems with Maple or Mahogany. And afterward the iron always happily resumed its life freshening clothes.

Best, Ted

[Reg Mitchell]

Throw it out in the yard cup side up over night. Get it in the morning befor ethe dewdrys and clamp it flat let dry. Should flatten it out
Reg

[Tony Bilello]

Maybe you experts could answer this. Once he gets it flattened, what is to prevent it from warping again? Wouldn't the flat-sawn nature of the wood still tend to make it cup?


Cupping direction goes against most logic. One would think that the cupping would go in the same direction as the growth rings and continue with the curve, however, it really goes in the opposite direction.
The easiest way to remember this is to think of the growth rings as wanting to straighten themselves out.

To answer Doyles questions, The board has been around long enough to have stabilized itself. If cut and reglued it will remain in the new position.
If it were me, I would have sliced the board down the middle, run the edges through a joiner (or a table saw) to form a new angle and reglue as in my sketch. Then he could have run it through his drum sander and flattened it out. With just a saw kerf, the reglued joint would only be visible to those that knew it was there. Since the wood has stabilized over the years, there would be no need to flip flop the boards.
As to hurting any perceived value of a 22" wide board, I would ask myself "self, do I depreciate the value more by splitting the board or by thinning it out or by thinking a 22" wide pine board has some value?"