TABLE TOP Glue-Up Tip / How To NOT Make a Flat Table Top

Hoping that this video will help someone avoid making the mistake that I made when gluing up boards for a dining room table. The boards should be glued with alternating end grain patterns to avoid cupping and warping.

[dcolorado]

Being experienced, I respect a young man who can openly share his experience of a project gone wrong. Thanks

[Billy-qhvp]

I graduated high school in 2002. In shop class they taught us to rotate the grain on a table top. So the concept has been around for a long time. It was just a blind spot for you. We all have them. You just learned the hard way, at least it wasn’t on expensive wood. Thanks for showing us! You probably taught many people that didn’t know either!

[timsharr]

I learned this end grain flip method a year ago and keep forgetting to make this an important step when arranging my boards for glue up. Thanks for bringing this up !

[joshcatstream]

Your video reached me and I won't make this mistake, so your efforts here were worth it.

[ronh]

Another tip is to make sure the material acclimates to your workshop and sticker the boards and leave a small gap between each board on the same level. Make sure the stickers are the same thickness.
Let it acclimate after each stage of construction and when you move it to a different area/location…, i.e. shop to garage, garage to house. Make sure you finish both sides of a table top. Not finishing both side can contribute to warping or cupping.
Also try to avoid buying boards that were either cut from the pith or right next to the pith. Boards that have the pith in them will warp the most. Try to use boards with a similar grain pattern on each face but especially the end grain. If the end grain (and face grain) are similar they will usually behave similarly.

[adamnonnenmacher]

Flipping the end grain does not matter. Some really experienced workers do not even bother with this. The biggest thing is making sure all the moisture is out of the wood. After glue up, never lay the wood flat without circulation or one side will dry out and begin to bow.

[TerrapinCreations]

The construction grade pine at the big box stores is hardly ever dry enough to make a flat table top from. Even if you altered the grain, you would end up with a wavy table top with each piece curving in the opposite way sorta like a potato chip. That would not keep the table top flat. The only way would be to kiln dry or air dry the wood completely. Then run it all through a planer to flatten each board before assembling.

[karenchilds]

I thought I was going crazy I tried everything. This is my first tabletop and I have just about lost my mind. Thank you for this! 👍👍👍

[patrikhafstrom]

Thank you for sharing not only successes ! But I belive the biggest reason was that the wood wasn’t dry enough. Construction timber is often new sawn when you buy it and need drying indoors or in a kiln if you want to use it as soon as possible. Then coating before it is dry will make it even worse.

[pushpendrarajput]

Definitely gonna try it. Seems so useful. Almost all of my tops end up like this or cracked from joints. Do share more tips man. Really appreciate it

[JG-mvqn]

Thanks for this information, luckily watched your video before it has happened to me Thank You

[whitepawwoodworks]

Moisture…. The thing that tipped me off is when you said, “2x6”.

Construction grade lumber isn’t always very dry. I’ve crosscut 2x6s before and noticed a distinct moisture ring inside the perimeter of the board. Construction grade lumber also doesn’t always have very dense growth rings making it more “floppy.” I occasionally build prototype doors with 2x4s and 2x6s. If I build with them immediately, the doors almost always warp. If I stack and sticker them for several months, a few will stay flat and stable but most will have a twist or bow.

Using furniture grade lumber from a reputable supplier should make things easier. Even furniture grade knotty pine will be more stable and dry than a 2x6. Alternating the “cup” in the grain doesn’t hurt but I don’t think it matters that much.

[MrJaxparadize]

Yeah. I used to just dry them on a flat surface with clamps and or weights. I just finished a desk and had the top sitting on a 4x8 work bench on pipe clamps and heavy blocks on top. Dried flat, no rocking. Remember to keep an eye on the moisture with a meter as well. You can get away without doing the up down thing, but it’s best practices. I only did it this way because of how the grain LOOKED. I also had to put in pocket screws. Country style.

[Bnann]

That sounds like a really good tip, thanks for sharing

[tooljunkie]

same w clamps one facing up and one facing down (parallel clamps) also clamping pressure plays a role.alot of ppl CRANK the clamps when in reality u only need to tighten them til u see 1st bead of squeeze out .i use my thumb and 2 fingers to tighten clamps for panel glue ups anymore than tht u risk cupping it.

[thewoodbox]

We’ve all done it I’d say. Lovely video!

[michaelhancock]

Well your first mistake was construction grade pine. Second, you're still going to get warpage even with alternating grain patterns. Best to glue up at a rough thickness. Glue adds moisture which can cause warp. Let your glued plank sit for 3 days to stabilize then surface it flat on a cnc or with a router and flattening jig then send it through the planer/ surface sander. Maintaining consistent shop temperature and humidity is also important. If it still cups after your final surfacing spray and wipe the concave side with water and put it wet side down on a sheet of platic it will flatten as it draws moisture through the panel.

[acemany]

If you didn't know that...you better call your old customers and ask them about them sold table lol. Glad you learn something and keep your thumb safe.

[nitrojunkie]

That is excellent advice. Funny I happened across this video, because this is an issue I'm dealing with now. I built a table top out of cedar and maple, glued it up, and that is all glued down to a piece of 3/4 oak plywood, and it still bowed. Not too horribly bad, mind you, but enough to create a little bit of a headache, and possibly having to start over. I might have to take a Sharpie and write in big, bold letters on the wall of the shop "CUT IN HALF AND FLIP IT" just as a reminder.

[jojo]

You need this book: Understanding Wood by R. Bruce Hoadley