Can warped boards be straightened?

[Monkeyleg]

I have in my new backyard a privacy fence made of lengths of 1" x 6" boards. They might be redwood, or maybe they're just stained to look like it. I haven't inspected them that closely.

There's a few that have warped at the top or bottom and come loose from the structure. Rather than try to make new ones or look for existing ones to match, I'm wondering if the boards can be submerged in water to soften them, then be fasted back on. I'm thinking that doing this might "warp" them straight.

Of course, I know next to nothing about working with wood. Could this work?

[Hawkmoon]

Sure -- until they dry out again. They warp because the grain isn't symmetrical. There's a possibility this fix might hold for long term, but the best repair is to replace. When doing paneling that we really don't want to see warp, we cut a few kerfs in the back (hidden) side, leaving a thinner face so any warpage doesn't have as much force to pull on the fasteners. But that only works where the back side is concealed.

[Monkeyleg]

But that only works where the back side is concealed.

Around here every house has a fence, so the side facing away from our yard is obscured by the neighbors' fences. So the the kerfs might work.

But what's a kerf?

[Brad Johnson]

But what's a kerf?

'Frek' spelled backwards.

Brad

[Monkeyleg]

sknaht.

[Hawkmoon]

Around here every house has a fence, so the side facing away from our yard is obscured by the neighbors' fences. So the the kerfs might work.

But what's a kerf?

It's just a groove, a sawcut that only goes 1/3 to 1/2 of the depth of the board.

A kerf will also weaken the board. If you want to try it, I'd suggest doing your wetting and straightening first, then use a Skilsaw to cut a couple of lengthwise "kerfs" before you nail or screw the boards back in place. Use screws -- they're much more resistant to pull-out. If you cut the kerfs first, the boards might break along the cuts when you try to straighten them.

[Perd Hapley]

But what's a kerf?

You're from the land of Paul Bunyan, and you don't know kerf?   

[KD5NRH]

There's a few that have warped at the top or bottom and come loose from the structure. Rather than try to make new ones or look for existing ones to match, I'm wondering if the boards can be submerged in water to soften them, then be fasted back on. I'm thinking that doing this might "warp" them straight.

The best way to do that would be to get something very straight and strong, like maybe a hardwood 6x6 of the right length, steam the boards, and clamp them to the straight piece until they dry.  Use a few spacers, so you're actually overbending the warped boards slightly, so that when they spring back on being released, they'll be straight.

[230RN]

kerf n. A groove or notch made by a cutting tool, such as a saw or an ax. The width of a cut made by a cutting tool.  The transverse distance between the offsets of the teeth of a saw.  Can also be applied to the width of a torch cut.  Usage: "Don't use a torch to cut kerfs in the backs of your fence boards."

from wiki: # Kerf: Width of the saw cut. On most saws the kerf is wider than the saw blade because the teeth are flared out sideways (set). This allows the blade to move through the cut easily without getting stuck (binding). However, some saws are made so that the teeth have no set on one side. This is done so that the saw can lie flat on a surface and cut along the surface without scratching it. These are referred to as flush cutting saws. Although the term kerf is often used to refer to the width of the saw blade, it actually means the width of the cut, which is affected by the width of the blade, the amount of wobble created during cutting, and the amount of material pulled out of the sides of the cut. This distinction can be important because the use of a blade that is too thin can result in excessive wobble and a wider kerf.

For steel in a lathe:



(Credit: http://www.mini-lathe.com/mini_lathe/operation/Parting/parting.htm)

The kerf is obvious here, though it's very close to the width of the cutter.

There.  That orta do it.

Ha.  Now you guys got me interested in the word's origins, so look out!

Terry, 230RN

(saw kerf diagram also from the wiki article.)

[Monkeyleg]

You're from the land of Paul Bunyan, and you don't know kerf?

The land of Paul Bunyan is Brainerd, MN. I'm from Milwaukee, the land of beer and brats.

Thanks for the replies. This sounds simple enough but, with my ability to really mess up woodworking projects, I expect the boards to all crack in half.

[Perd Hapley]

The land of Paul Bunyan is Brainerd, MN. I'm from Milwaukee, the land of beer and brats.

My apologies.  The "kerf" is (among other things) the notch cut in the trunk of a tree, in the direction it is intended to fall.  When using a chain-saw, the kerf is also the wooden wedge that is removed from said notch. 

[Sergeant Bob]

The land of Paul Bunyan is Brainerd, MN. I'm from Milwaukee, the land of beer and brats.

Thanks for the replies. This sounds simple enough but, with my ability to really mess up woodworking projects, I expect the boards to all crack in half.

One thing I love about these forums is the vast quantities of available wisdom.

I now know where Paul Bunyan is from, what a "kerf" is, and that Wisconsin is full of fat drunks.

[Doggy Daddy]

I now know where Paul Bunyan is from, what a "kerf" is, and that Wisconsin is full of fat drunks.

I knew 2 out of 3 before reading this thread.   

DD

[Harold Tuttle]

I thought that was swarf

[Harold Tuttle]

[Sergeant Bob]

He said "warped", not "Worfed".

[sanglant]

if your willing to invest enough cash, you could stabilize them. meaning using a vacuum pull epoxy through the grain. but i have never heard of anyone setting up to do pieces that size. maybe some thin CA glue soaked in from the unfinished side?

[Perd Hapley]

He said "warped", not "Worfed".

I think that picture counts for both.

[KD5NRH]

I thought that was swarf

Swarf is the stuff that was in the kerf.

[Scout26]

One thing I love about these forums is the vast quantities of available wisdom.

Sadly, not much of it is useful.....



My college roommate was from Brainerd, MN.  One of the previous jobs listed on his resume was "Operated Largest Talking Animation in the World, the 26ft tall Paul Bunyan at the entrance of Paul Bunyan Land."

[Tallpine]

A kerf is where sawdust comes from 

This topic is a good springboard for conversation. 

[charby]

Student of Forestry here, more than likely the board will return to its warped shape. Check out this paper on some wood geek. http://www.fpl.fs.fed.us/documnts/pdf1987/maegl87a.pdf

[Harold Tuttle]

a proper installation with the right materials is dimensionally stable,
It's hard to fix something that wasn't installed correctly.

[Monkeyleg]

:D:D:D

OK, I'll try it on just a couple of boards to see if it works. That is, I'll try it on a couple of boards in a couple of months when it's not in the 90's and humid.

[gunsmith]

even the most warped board can be made straight if he lets God into his heart.