Hey everyone, I'm new and I've just built my first dining table 70" long , the wood I used has been in the barn for about 4 years stacked with sticks between every layer, I brought it in the shop and let it take 2 weeks between planing and the time I started glueing . I glued the top into 2 pieces making sure I clamped straight edges on to keep them straight, and then put the 2 half's on the frame and clamped and glued them together with straight edge clamped to them , after another week in the shop putting tongue oil finish on I took the table in the house , after sitting in the house for a week this table got a bow in the top , I rushed it back to the shop and put tow straps on the legs and pulled it back in over a couple of days ,
My question is , will this table bow again when I take the straps off ?
Help . Lol
Welcome to LumberJocks. Your profile doesn't show where your located or anything about your shop, but it sounds like your home has quite a different RH than your shop. In my experience, air dried wood doesn't seem to be as stable as kiln dried. If your shop isn't conditioned like your house, then then it's unlikely the MC of the wood changed much from being in the barn - until you moved it into the house.
If you can get it to flatten out again in the shop, I think the best advise is to make sure all surfaces are equally sealed so that as the wood looses moisture in the house, it does it as evenly and slowly as possible. Good luck.
Alternating grain direction is hocus pocus. Always glue up table top for the best look.
I have found table tops will warp for lots of different reasons and for no reason that we can predict.
For me I've learned how to pick boards that are somewhat predictable. When and how I handle them is important for success.
Always arrange the boards for harmony or the table not worth making.
Good Luck
I haven't posted this for a while, but since the alternating grain fallacy was mentioned, time to put it back out there.
Tage Frid on Alternating Rings
"Another thing most books tell you is to alternate the wood to compensate for the cupping caused by shrinkage. This would be fine if you wanted to design a washboard. But if you want to use your wood, for example, for a tabletop, it will take a lot of screws to hold it down, plus every second board will usually have a lot of sapwood, especially today with the shortage and high cost of wood, where every piece must be used. But, if we don't alternate the wood, it will work together and form an arch that will be very easy to hold down with a few screws. Also, we will have the center of the wood facing up, meaning less sapwood, better color, harder and usually fewer knots."
Here's my tip for anyone interested. Looking at the end of a board or Rich's picture see the curved growth rings.
Many times this is how a board will cup because the growth rings are trying to flatten out. Or become straight
Not always but it's a good bet.
Good Luck everyone
Rich,
Thanks for posting that. I've seen a lot of (heated) arguments back an forth on the subject, but that was concise and makes a TON of sense to me in a way it never did before. Now I feel like, DUH - if the bow is in one direction it's easy to straighten; and if it's up in the center, even better - you can pull it down with a screw! I'm going to try and remember this when it's my turn to build a dining table.
RWNDY, good luck - I have no advice for you, and it's a bit late for you to align your boards - but please post back again to let us know what worked, if anything! And post your table as a project!
I should have noted that the Tage Frid quote was taken from an article he wrote in Fine Woodworking Issue #2 in Spring 1976.
Back to the OP (although as so often happens here, he hasn't followed up on the thread with more information). I would recommend attaching some battens to the bottom of the table to pull the bow out. Be sure to allow for wood movement, etc.
I second Steve's question above. Need some more info on the construction (or some pics) to help you out with some probable solutions. Also, what kind of wood?
My preferred method to prevent table top movement is the old tried and true bread board ends. Not sure if you have any more of the same wood left over, but it should be a relatively simple process to add some bread boards to your existing top… ask me how i know . There are a couple ways to approach that but again, would like to know more before I chime in with anything specific.
- Steve
I have no pics of the bow , I glued the top all the way around the frame and it has one crossmember in the middle and I glued it too , the bow was in the middle, I put tongue oil coats all the same coats top and bottom and frame and legs , I took it back to the shop and was able to pull the bow out and put 4 coats of laquer finish on top, can I take the table inside the house and leave straps on the legs for a week or 2 or do I need to put extra supports you were talking about but I need more info on what you was saying , I put 1 cross support in the middle
- Steve
I have no pics of the bow , I glued the top all the way around the frame and it has one crossmember in the middle and I glued it too , the bow was in the middle, I put tongue oil coats all the same coats top and bottom and frame and legs , I took it back to the shop and was able to pull the bow out and put 4 coats of laquer finish on top, can I take the table inside the house and leave straps on the legs for a week or 2 or do I need to put extra supports you were talking about but I need more info on what you was saying , I put 1 cross support in the middle
You don't say the WIDTH of the top. If the grain was running long, IOW with your 70" length, then any, and all shrinkage, and movement will be across width of the top. You don't mention your location, but it is 75 to 90* here right now, and pretty humid with almost daily rain. A project here made out in an unconditioned place, and brought into a nice air conditioned home could conceivably have movement on the first day.
Your use of glue to NOT allow that top to move as it will want to do, is likely your cupping issue, and it will only get worse going into a winter.
Proper installation if a top of any size, especially one of the length, and maybe the width you could have here requires the use of fixation devices to secure the top, but ALSO allow it to move seasonally.
Woodworking is all about learning. From the looks of your frame it is done well. Likely you will learn one of the most valuable lessons here. Wood moves, you need to allow for it. It never gets longer, it sure does get wider though. Depending on width and species of wood, thickness, and varied degrees of temp, and humidity it can be a lot, or just enough to cause trouble, but it moves. FWIW if you polled everyone here, probably a lot of them have done what you did. About half of most woodworking videos are shots of people smearing glue all over everything…......
I sure wish I would've seen that video last year . I've built bed side tables too . Anyway the grain is going crossways on the dining table as is 40" across.
Am I just screwed on this and chalk it up with bad learning experience or is there something I can do to save it? . My bed side tables i built I had the white oak kiln dried but this red oak dining table is air dried a few years in the barn
It's pretty clear from this and your other photo that the grain runs across and not down the table. Nothing wrong with that, but it's a factor in the bowing you're seeing.
The key is that you glued down the top to the aprons. Since the aprons are long grain, the grain on the top is at 90º to the apron at each end (end of the table top grain, not end of the table). Because you oriented the grain across the table and didn't allow for movement by gluing, as the top changes with moisture, it will bend those long apron pieces.
Had you oriented the top the way most are-down the length of the table-it would have had less tendency to bow because of the shorter aprons.
Either way however, you are going to have cracks form in the top when you glue it down like that.
Your best course of action is to separate the top from the base and re-attach it correctly. Whether you fashion your own blocks, use figure-8s or Z-clips doesn't matter, but that top has to be able to expand and contract without interference.
Hopefully, the aprons are just being bent by the movement of the top and will straighten when freed. Any slight bow remaining in the top should get pulled out when you attach it, but worst case you might have to run a couple of battens down the length of the top to pull it flat.
Thanks guys , it looks like I'll have to break out the sawsaw and remove the top , that's the best I can think of , and re anchor as you said . This is definitely a hard learned lesson for me , goes to show your never to old to learn. Thanks again .
Hopefully I can post my finished product when the rework is completed
What Rich said. Also, Steven is more honest than the rest of us. We've all done something similar at some point and "learned the hard way." This is definitely fixable per Rich's reply with a top-to-apron attachment that allows for movement.
Whatever way you go, I would allow for up to 1 inch of movement.
I would also suggest giving some thought to beefing up the aprons and maybe a couple stout battens running lengthwise (of course applying the same principle of fastening to allow movement.
It's a fallacy, just like alternating growth rings.
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