Working With Wide Boards

[Joe Jensen]

How do you guys who use wide boards control warpage once the project if finished? Say to do a table top with 12" wide boads. How are you holding down the top to allow movement, and still control warpage?

I was taught to never use boards more a width more than 8X the thickness. I cheat a little, but not much. The only time I did wide boards were some 3/4" thick drawer fronts that were 6" wide. Some have cupped a little over time.

Apparently I'm too paranoid here. Can you shed some light on my ignorance :confused:

[Jim Becker]

There are a lot of myths about board width. The fact of the matter is that lumber that is properly dried is not going to cause you problems if you build your projects with good techniques that accommodate normal wood movement. I choose a wide board every time I can and when it is necessary to glue up for total width, I take great pains to do grain and color matching to try and make the joint completely disappear.

If you have experienced cupping, then that's an indication that the workpiece is not fastened well to the project. Take your example of a very tall drawer front. With normal wood movement, you cannot use glue so screws are used to fasten it to the drawer box. Given the nature of the size, you'll need to put fasteners both at the bottom and the top, but you must accommodate expansion...so one row of screws has a slot in the drawer box for the screws to move in. The front stays tight to the box, but can move seasonally.

[Greg Robbins]

Years ago when I first started woodworking I took a class from Frank Klausz and he is a proponent of wide boards. This is how he explained to control wide boards. Boards want to cup away from the center of the tree. Also, he says that the side of the board that is toward the center of the tree is the best grain, so that should be the side that is showing. This way he says, if the board wants to cup, it will cup out, or away from the piece your making. You attach the center of the board with clips, such a a Z clip, on both ends and in the center if possible. This way if the board decides to cup it will try to cup up in the center, but if can't so it will expand outwards. You allow for your normal cross grain movement. I've been using wide boards (when I can get them) ever since and using this method, have never had a problem. This is for a table top. Hope this makes sense.

[Brent Ring]

Years ago when I first started woodworking I took a class from Frank Klausz and he is a proponent of wide boards. This is how he explained to control wide boards. Boards want to cup away from the center of the tree. Also, he says that the side of the board that is toward the center of the tree is the best grain, so that should be the side that is showing. This way he says, if the board wants to cup, it will cup out, or away from the piece your making. You attach the center of the board with clips, such a a Z clip, on both ends and in the center if possible. This way if the board decides to cup it will try to cup up in the center, but if can't so it will expand outwards. You allow for your normal cross grain movement. I've been using wide boards (when I can get them) ever since and using this method, have never had a problem. This is for a table top. Hope this makes sense.


Greg,

Is it possible you could diagram this? I am not quite understanding, and please excuse my ignorance

[John Thompson]

You might want to clarify to Greg if you are having trouble understanding how to place Z clips.. or are you referring to understanding how to determine what the face side closest to heart is?....

I was taught the same thing back in the 80"s by Frank Klaus in a class given by him. I used the method he described on a chest top just yesterday. Once you have determined the face likely to cup up from the carcass.. you simply use the Z clips (or your own creation) to attach the lenght center-line of the glue up.

Then use figure 8's on the bottom of top corners that attach in splines on the outer corners of the carcass for hold down with the spline allowing side to side expansion to move in and out seasonally. You will have to wait on Greg to map it out as I am not a computer guy with the knowledge required to do drawing or much else with these things for that matter. :)

Good luck...

Sarge..

[Bill Wyko]

You can also use a figure 8 bracket. This allows the wood to move independently from the rest of the material. It really depends on the application.

[Greg Robbins]

You will have to wait on Greg to map it out as I am not a computer guy with the knowledge required to do drawing or much else with these things for that matter. :)

Good luck...

Sarge..

Sorry it took so long to get back here. I don't have the ability to draw something up either. But Sarge's explanation of attaching a top is a good one. Now if you're wondering about how to tell which side of a board is the inside of the tree... Just look at the end grain. As long as it's not quarter sawn, it will have the growth rings either curving up or down. Think of it as a smiley face. If it's smiling at you then the top is the side that was toward the inside of the tree. If it's frowning at you, then just flip the board over. I've found over the years that this really is true, most of the time. Meaning the side toward the inside of the tree is the best grain. I may not be explaining this very well but I hope I am. :o

[Steve Kolbe]

You can also use a figure 8 bracket. This allows the wood to move independently from the rest of the material. It really depends on the application.

woof - OK. I kinda lost here too. I even did a google search for the figure 8 bracket, and didn't find much!

...and accomodating for seasonal expansion on a cabinet just blows my mind. Is this for something in a climate controlled home - or a garage?

Sorry for being a little slow to wrap my head around this... maybe I should just go get some sleep first!

[Greg Robbins]

woof - OK. I kinda lost here too. I even did a google search for the figure 8 bracket, and didn't find much!

...and accomodating for seasonal expansion on a cabinet just blows my mind. Is this for something in a climate controlled home - or a garage?

Sorry for being a little slow to wrap my head around this... maybe I should just go get some sleep first!

These are the table top fastners that I use.
http://www.rockler.com/product.cfm?page=784&filter=table%20top%20fastners

I believe these are the figure 8's that are mentioned.
http://www.rockler.com/product.cfm?page=786&cs=1

[John Thompson]

Sorry it took so long to get back here. I don't have the ability to draw something up either. But Sarge's explanation of attaching a top is a good one. Now if you're wondering about how to tell which side of a board is the inside of the tree... Just look at the end grain. As long as it's not quarter sawn, it will have the growth rings either curving up or down. Think of it as a smiley face. If it's smiling at you then the top is the side that was toward the inside of the tree. If it's frowning at you, then just flip the board over. I've found over the years that this really is true, most of the time. Meaning the side toward the inside of the tree is the best grain. I may not be explaining this very well but I hope I am. :o

Interesting and a clever description as I thought of the smiley face after I posted last night. :)

That's an excellent way of describing it as the occasions that I point it out to someone are usually in a shop with stock that you can physically point to. I suppose you have to come up with clever little things as such to do the same thing on the internet where a picture is not available.

BTW... I use the table top Z attachments also over the figure 8's. I just ordered about 40 of them several days ago as stock is running low. 9 will get used within a week or so...

Regards...

Sarge..

[David DeCristoforo]

FWIW, this is my preferred method of attachment. The "clips" are about 1.25 X 1". Easy to make and attach.

85143

YM