Dealing with Warped Wood

Perhaps the woodworker’s biggest nightmare, warped wood can be extremely frustrating to have to deal with. But with a little experience and a couple tricks up your sleeve, you can save yourself from a pretty major headache.

Wood is often imperfect

A common mistake beginners make is assuming a piece of lumber is straight “because they bought it at the home center”, and finding out – painfully – that it’s as crooked as a dog’s hind leg. For the record, just because someone’s selling it, it doesn’t mean it’s straight or “A grade”, and it also doesn’t mean it will STAY straight even if it is so initially. When constructing areas of the house that require straightness, such as door & window frames, wall corners, etc, it’s quite crucial that your boards are

Types of warped wood

straight. Any more than a 1:2~3000 (1mm every 2 to 3000) bow is unacceptable for most precision projects. A habit I have when buying lumber at the local home center is checking the straightness of the piece by putting my eye on the corner and looking down its length.

With this method you should be able to easily detect bows as well as twists – which are equally if not MORE agonizing! But when all is said and done, there will be times when for some odd reason you still seem to wind up with that confounded “S” shaped board! Like I mentioned earlier, wood often doesn’t seem to want to stay the same shape. In fact, “new” wood, or wood that hasn’t been dried, will most certainly change shape in some way. That’s one reason quarter-sawn wood is so expensive – because due to its grain, it’s considerably less likely to warp or twist. (It’s also in large part due to its beautiful patterns.)

Dealing with the Consequences

Anyway, for those of us who can’t afford quarter-sawn boards just for a funky window frame, but want to make it look halfway respectable, we may need to opt for the cheaper “flat-sawn” boards. Having said that, I’m happy to add that flat-sawn boards are more than sufficient as long as you choose them right – or are prepared to “deal

A: Quarter-sawn; B: Flat-sawn

with the consequences”. “Dealing with the consequences” however, may not be as bad as it sounds. To deal with a board with a warp along the length of the edge (crook), all you need to do is trim off those offending edges.

Take a straight-edge and use the method I outlined in “Cut a Perfect Line with a Circular Saw“. (This method will not work with larger lumber that’s thicker than the saw blade’s maximum depth.) Because you will be left with a board that is shy the amount you just trimmed off, it’s wise to purchase wood that is slightly wider than actually necessary when there is a risk of warping – which is in most cases and especially when you might not be using the boards right away. Note that the longer wood is allowed to sit and “season”, the more time you’re giving it to warp.

Dealing with twists in your boards requires a more “brute force” course of action. Assuming the board will be straight as long as you bend it “flat” and keep it that way, what needs to be done is fairly straight-forward. You simply need to come up with a way that forces the wood to bend in the direction you want it to, while at the same time ensuring the other side doesn’t “follow”. For example, say you want to build a very simple rectangular door frame but your vertical boards look like screws. (Note that in real life there is only a certain degree of twisting a piece of wood can be “made” to recover from without splitting.) Attach the 2 vertical boards to the top horizontal one first.

This will essentially “lock” the 3 sides to each other. You now position the somewhat delicate frame into its place in the wall. Because the top half has been secured together, it should now be “locked” between the wall studs unable to move except by applying force with a mallet or such. But the bottom half of course is still free-hanging like a rag doll and can be manipulated at will. Being that the vertical boards were twisted and you secured the top ends at 90 degree angles, the bottom ends should now be displaying the full glory of the twists.

Board hammered down to Force Twist out

Make your final position within the wall studs and pop a screw up near the top through the studs and into the frame. – You probably don’t want any visible screw or nail heads on the face of your door frame. This is to secure the top end so it won’t shift, leaving you to confidently focus all your energies on the bottom end. Cut out a scrap board that’s as wide as the door frame is supposed to be, and with a sliver of plywood on either end to protect the frame surface, hammer the board down into the side of the frame that’s twisting in. This will essentially force the twist to flatten out.

Screwing from the studs into the frame only works if the frame board is thick enough, otherwise you’ll have to go from the face into the studs. You can conceal screw or nail heads by adding a piece of trimming over the row of heads, or if you’re going to be adding a door, the door stop trimming can do this for you. The only problem is that if the vertical frame board is too twisted, screws along the center won’t be in the right position to pin the twist down. In this case, the only alternative if you still want to use this board, is to counter-sink the screw/s in the proper position – most likely on one of the edges – and putty up the hole afterward.

Being that it’ll be toward the bottom of the door frame, it won’t be so noticeable, but you’ll still have to be prepared to live with an imperfect frame if you go this route. But at the end of it all, you may find that it’s best to just start out with better wood even if it is a bit more expensive. Not everyone has what it takes to patiently work with flawed materials and somehow make it turn out like there was nothing wrong. This is something that takes experience, skill, patience, and sometimes just pure luck! Weigh out the pros and cons and don’t be penny-wise but pound-foolish! Time is money so you should factor in man-hours on the project when calculating what’s more economical.

Comments are closed.