chaplaindoug created the topic: Placement of Twisted Boards
I am making a 82" x 38" poplar table top out of eight 7/8" thick boards. Two of the boards are slightly twisted. What would be the best place to put these boards? Would placing them inside the table top (one or two boards in) be better? Or would placing them as the outside boards be better? I was thinking inside, but another woodcrafter suggested putting them on the two outer edges of the top. Which is better? Or is there something else I should do?
colin replied the topic: Placement of Twisted Boards
Twisted boards is tricky no matter what you do with them. Really hard to answer questions like this because there are so many variables, like what is the moisture content of the wood, how bad is the twist, where will the table be living after it is made ...
What I would recommend is to get at least one side of each of the boards flat, at least that way you can get good edges and glue all the flat sides together to be the face of the table. The underside of the table will have a couple of boards that will be thinner on one side at one end, but at least you will have workable wood you don't have to worry about.
eric422 replied the topic: Placement of Twisted Boards
If there is one thing I hate most about milling lumber, it's dealing with twisted boards. I think the best thing to do is to try and stabilize the board as much as possible. I don't know how bad the twist is, but if it's bad, then it will eventually start to crack and might work its way down the board. I also don't know what kind of tools you have, so I'll make a couple suggestions.
One way to address twisting is to cut the tension out of the board that makes it twist. A rip cut down the middle should be okay for boards that aren't too wide.
I do not recommend doing this on a table saw though. This is because the twist can bind into the back of the blade when cutting it, which will cause a kickback. Also, a twisted board is unstable as it tries to rock from side to side when cutting it. So don't use a table saw. A jig saw, bandsaw, or a hand saw should work fine. Once the pieces are cut then you can flatten the boards, square up the edges and glue it back together.
If the board has a little twist, then you can probably just flatten one side with a hand plane, jointer, router, or a belt sander. Then surface the other side to thickness if you have a surfacing planer.
Note - Make sure to watch the link below on using a router sled to flatten wide boards
Winding sticks are very helpful when removing the twist out of a board. If you're not familiar with them, all they are is two straight sticks that are placed at the ends of the twisted board. If the board is twisted then the sticks won't line up when looking down the length of the board. If the twist is gone, then the sticks will line up parallel to each other.
Here are some youtube videos which shows how to save your twisted boards:
Here is a video that shows a cool way to flatten a board with a router sled
I think its best to avoid using twisted boards. But if it's all you have then there are methods that will help you save those boards. The bottom line is to take out the twist so that it doesn't ruin your project. Boards that are bowed, or cupped aren't very difficult to take out, but twisted boards are my arch enemies.
Derek replied the topic: Placement of Twisted Boards
An excellent response Eric.
My advice on this is straight forward for this issue and that is to find another piece of wood that is more suitable. If that is not an option, then I would consider some of the techniques Colin and Eric have mentioned but not having enough information on the wood such as the final board thickness desired, is it still green wood, is it air or kiln dried etc. Remember, furniture wood must have 9% moisture content and if at all possible a two to three week acclamation period at the final destination of the piece.
Table top boards must meet some very critical criteria before they can be selected with any confidence. When a board has to be taken through a process such as score cutting the underside, ripping and then gluing back together or flattening through the removal of material I would seriously try and find some better boards first which would greatly enhance the final outcome.
To get back to the core question asked, I think any slight twist can be pretty much eliminated and made to behave over the long term and I would make it disappear buy placing them on the outside boards of a table. The trained eye can discern minor deviations but most people would never notice it. The choice of staining, painting, dying along with a protective finish can also help with tricking the eye into our intended deception. While seated, most people will pick up any defects in the middle of a table much more easily than the outside portion.
"Pick your battles" Chaplain Doug and I hope you have found some helpful info.
chaplaindoug replied the topic: Placement of Twisted Boards
Thank you so much Derek for a thorough and thoughtful (and gracious) response. I find myself "doing time" over defects (real or perceived) in most of my projects. I am a perfectionist in recovery.
After so many responding that I should not use the slightly twisted boards, I asked the mill for two replacements. However, in the mean time, I glued them into the top just to see if they would straighten out if placed between two straight boards. That does not really work. So I am cutting them out and replacing them.
By the way, the master wood worker who trained me gave the same advice as you, i.e., putting the boards on the outside.
Again, thank you and God bless you for taking time to answer.
P.S. The boards are poplar, 15/16" thick and dry.
Also, thanks to all the other responders. It is great having help!