Issue with white oak glue ups

[Sparktrician]

Rick, I made a cherry coffee table a few years ago.  The top was from a single, well-machined board that had been very carefully planed down to 4/4".  I cut it into three pieces to be side-joined.  I did the glue-up and clamped it using cauls to keep things straight and true.  When I went down to the shop the next morning and released the clamps and cauls, everything looked OK, but that afternoon I checked with a straightedge, I saw some arching. 

I went ahead and machined the edges as I wanted them and checked again with the straightedge.  Yup, getting more curved.  Nonetheless, I went ahead and cut the domino mortises in the legs and top, then did the glue-up.  I inverted the table so that the top was down and legs up.  I clamped the works down securely to a set of dead-straight Douglas fir rails that I use with my flattening jig. 

The next morning I took the clamps off and let the table sit for three days, checking again that the top was straight and true.  It was, so I applied the first coat of finish, followed by two more coats.  The top stayed straight and true, so it migrated upstairs into my family room where it sits today, still straight and true. 

 

[Rick Herrick]

Thanks again for more info.  One of the things that is easy to control is stickers.  What do people use?  Been googling a lot and some of the options are just not possible for the small hobbyist.  Can you use ply wood or do they have to be hardwood and do they have to match what you are drying?  One thing I read is you need to heat them after one use to keep insects from taking over.  I assume that most of what I am reading is geared toward folks that actually mill logs for themselves or a business. 

I have a bunch of scraps that I can turn into stickers.  What I read is they need to be 1x1.  Is that really necessary?  Don't want to over think this though.

 

[ChuckM]

Stickers:

Any scrap strips 1/2", 3/4" or 1"; square or rectangular (long enough) -- plywood or soft/hardwood, it doesn't matter.

For smaller pieces with no risk of rolling, bamboo sticks -- dirt cheap, sold at any grocery chains.

 

[Rick Herrick]

Thanks Chuck.  Lots of ply scrap so that's good to know.  Would have never guessed to use to the bamboo sticks in certain conditions.

 

[CeeJay]

One of the earlier posters mentioned this method.

Place the board cupped side up. Wet the surface then cover in a moist towel. Leave it a while. The moisture will penetrate the cupped side and expand the fibres which will flatten the board. Once it’s flattened, sticker and weight it, leave for a week or two.

Usually it will stay flat, and then once assembled with frame-legs etc will stay flat.

Good luck. Above points regarding quarter sawn etc will help avoid this in future but won’t help with the pieces you’ve already made.

Sent from my iPhone using Tapatalk

 

[Rick Herrick]

Thanks CeeJay, I have it weighted now just to see what happens but I will try the towel method next.

 

[mrFinpgh]

Thanks again for more info.  One of the things that is easy to control is stickers.  What do people use?  Been googling a lot and some of the options are just not possible for the small hobbyist.  Can you use ply wood or do they have to be hardwood and do they have to match what you are drying?  One thing I read is you need to heat them after one use to keep insects from taking over.  I assume that most of what I am reading is geared toward folks that actually mill logs for themselves or a business. 

I have a bunch of scraps that I can turn into stickers.  What I read is they need to be 1x1.  Is that really necessary?  Don't want to over think this though.

1x1 matters much more if you're air drying lumber.  For already dry stuff, anything that gets air flowing evenly around both asides is good.

Most of my stickers are offcuts from plywood, but I've used solid wood and even leftover base cap and quarter round molding to get space between boards.  No negative effects that I've observed.

 

[Packard]

This illustration shows how grain affects glue-ups.

https://woodadvocate.com/2014/07/28/the-secret-to-flat-panels/

Whether you are trying to restore a table with a warped top, figure out why your cabinet or passageway doors are warped, or you’re a woodworker looking to fine tune your projects, understanding what causes panels to warp and how to prevent it can be the difference between getting it done and getting it right.  When working with solid wood or plywood, preventing panel warp is possible.  Although solid wood and plywood have inherent differences the fundamentals are the same.  Panel warp can be caused by the materials, construction, processes, or environment.

I would rip these on the table saw into narrower pieces and alternate the grain.  I don't think you can flatten it sufficiently otherwise.

 

[Rick Herrick]

Thanks Packard.  There are several comments here on this but whats odd is one of the two boards I did correctly (alternating end grain) is the one that warped the most.  I also think the thinner the material the likely these cupping/warping issues happen.  Since I have the extra wood, and other options, I will play with these two and see how the flattening, wetting and then flattening work out.  But its a good suggestion to re-rip and start again.

There was one comment above and I think it might have referred to also alternating face grain.  I tried to keep all face grain going the same way is it was going into the thickness planar all glued up.  If I thickness'd the boards first and glued up second, would alternating those face grains lessen my issues ?

 

[Cheese]

Trust but verify. you really don’t what you are starting with without measuring it yourself.

I use and really like this one from Wagner. It’s a pinless one that works well.

Hey Ron [member=3192]rvieceli[/member] what do you like about that particular meter and what are your go/no-go limits for wood moisture? I've never used one before, I just pray a lot and often.  [big grin]

 

[ChuckM]

Thanks Packard.  There are several comments here on this but whats odd is one of the two boards I did correctly (alternating end grain) is the one that warped the most.  Snip.

Alternating the grain DOES NOT guarantee that warping or cupping won't happen; it simply reduces the severity or chance of "disformation."

I belong to the school (led by people like Tage Frid, Sam Maloof, etc.) where alternating the grain is not a consideration when we edge join panels or boards that will show. Our first foremost consideration is how the piece will look after the process. James Krenov made sure wood was stable before he used it, while Frid actually called alternating the grain one of the "Textbook Mistakes" (Fine Woodworking -https://www.finewoodworking.com/1976/04/01/textbook-mistakes).

I don't alternate grain consciously, but if a panel is alternated, I'm fine with it. Rough lumber usually stays in my shop for months -- not days or weeks -- some even for years before it's used. I have had very little experience of wood warping or cupping on me after a piece is built. If twisting happens after a board is thickness-planed, I remove the twist (after which the stock may become thinner or narrower or both) and use it for something else. I always budget for wastage -- whether it's due to blunders or wood movement.

 

[Packard]

I'm a plywood-guy.  I've glued up a handful of panels.  I do read extensively before undertaking a new process.  I followed this advice.  I did not have warping issues.  I was working in pine, however.

 

[Michael Kellough]

Moisture meters are not as useful as you might think, unless you are working with wood that has never been seasoned (dried to ambient equilibrium by one means or the other) and you want to use it as soon as possible.

If the wood has previously been seasoned and has been stored under cover a plain old $10 temperature/humidity meter is more useful because all you really need to do is bring the wood to equilibrium with the climate where the finished product will reside.

It only takes a week or two for stickered boards to reach equilibrium so if the shop is too dry or too wet you can make a microclimate with plastic and use the $10 meter to tell whether you need to add or remove moisture in the enclosure. It takes less time acclimate if the thickness is close to the finished thickness, more if it will be substantially reduced. It makes sense to go ahead and plane it down some before fully acclimating if you’re in a hurry.

Adding moisture can be as simple as adding a wet pressure treated board or a pail of water to the enclosure. In the summer you might need to put a small dehumidifier in the enclosure. Knowing the specific moisture content of the wood is way less important than knowing it is at equilibrium.

Stickers for dry wood can be made of anything. Stickers for green wood are more critical the wetter the wood is. In that case you want stickers that are rot resistant so they don’t transfer fungus stains to the good wood. It’s also better to add diagonal channels to the surface of the sticker so air can get between the sticker and the good wood. The best stickers I’ve seen were substantial (30mm square) purpose made straight sticks meant to last for decades. I don’t know the species as the wood had weathered to grey and I don’t speak Japanese but they had deep diagonal grooves on the contact surfaces to allow air circulation.

 

[Rick Herrick]

Thanks Michael, very valid points.  Since my skill level is low, I only use hardwood from a couple of reputable suppliers here locally.  I have one of those ~$40 meters but its very hit/miss whether I get a reading or not.  But every time I do, its usually between 5-8% so I am assuming I am good.  If I was buying wood from all over, including saw mills, I probably would get one of those more expensive meters but its probably not in the cards for me.

 

[Michael Kellough]

ChuckS wrote “Our first foremost consideration is how the piece will look after the process.”

This. 

If you go to the trouble to make something take the extra steps (and extra wood) to make it look good. My pet peeve is seeing a nice construction spoiled by poorly matched boards. Especially something like a gash of bright sapwood jutting into a dark field of beautiful walnut.

Buying hardwood means dealing with random sizes and grain directions but you don’t have to accept a given edge as part of the project. Use the track saw and cut a taper to make the edge parallel to the grain, or to get rid of that random strip of sapwood.

 

[Rick Herrick]

I agree 100%, which is why I subscribe to Chuck's words

"I always budget for wastage -- whether it's due to blunders or wood movement."

The reason my two samples didn't match grain wise is because I am trying to get the best looking face I can so I wasn't watching for the grain issue.  But I believe my biggest mistake here was simply taking off way too much wood via the planar, in one session.  I will never do that again.  Patience grasshopper.....

This is my first fine woodworking (as least finer than what I have done up to this point) project and its for my first grand child so I feel more than a little pressure to not screw this up.  I did find some white oak 1/2" plywood panels that looked good on the web.  I figure its worth a shot to have it here just in case.

 

[rvieceli]

[member=44099]Cheese[/member] the Wagner 910 for me is a great meter. It’s pinless which means you can check any where on the wood without knocking a couple of pin holes in the piece. Means it’s seller friendly. Most folks only let you stick the ends with the pins which doesn’t tell you a lot. There are adjustments for different species of wood. I believe that takes relative density of the wood into account.

There are meters that are more expensive but Wagner has a good rep. It has a button to press that holds the reading on the display.

The 910 only has one depth of reading around .75 inches which works for me because I rarely work with anything under 1.5 inches. The 930 is a dual depth, .25 inches and .75 probably a better choice for a lot of folks.

Realistically in the area I’m in, even if it comes out of the kiln at 6-8% the stuff tends to drift up to 9-11% the humidity is high most of the year.  Typically I tend to shoot for 8-9% but I’m ok with 10%

It’s the 17-18% that get you.

Ron

 

[Rick Herrick]

[member=44099]Cheese[/member] the Wagner 910 for me is a great meter. It’s pinless which means you can check any where on the wood without knocking a couple of pin holes in the piece. Means it’s seller friendly. Most folks only let you stick the ends with the pins which doesn’t tell you a lot. There are adjustments for different species of wood. I believe that takes relative density of the wood into account.

There are meters that are more expensive but Wagner has a good rep. It has a button to press that holds the reading on the display.

The 910 only has one depth of reading around .75 inches which works for me because I rarely work with anything under 1.5 inches. The 930 is a dual depth, .25 inches and .75 probably a better choice for a lot of folks.

Realistically in the area I’m in, even if it comes out of the kiln at 6-8% the stuff tends to drift up to 9-11% the humidity is high most of the year.  Typically I tend to shoot for 8-9% but I’m ok with 10%

It’s the 17-18% that get you.

Ron

Added to what Ron said, from what I found yesterday, their customer service is great and they have a 7 year warranty on their meters.  Looked like the Orion 910 was their lower end (around $370) and the Orion 950 was higher up (~ $550), with a couple others in between.

 

[Cheese]

Thanks Ron...good things to know.  [smile]

It seems like the 930 meter is a better match for my work. Usually working in the 1/2" to 1 1/4" range.