straightening a wide cupped board

[Mike Gager]

was watching NYW today and norm was building a small table using reclaimed pine boards about 12-15 wide. the boards were cupped and he was talking about ways to get them flat enough to plane. normally you would rip the board in half and and joint and plane the 2 halves and then glue back together but he didnt want to cut the boards

instead he made a kerf cut down the middle about 3/4 of the way through the board and then pressed down on the opposite side which more or less flattened the board before running it through the planer. after planing the boards and edge gluing them into a panel he took some sort of wood filler and filled the saw kerfs

i had never seen or heard of this being done before. does anyone do this? it doesnt seem like it would work very well to flatten the boards as i would think they would still have some cupping. it didnt show him running the boards over the jointer

[Russ Boyd]

I don't have any experience with that particular method, but It would work. The kerf cut relieves the stress in the board and the planer would push it down a bit making a pretty flat surface. I wouldn't want that piece for a top as I don't think it would be strong enough, but a side or back should be fine.

[glenn bradley]

Same approach as making benderboard, just isolated. Seems viable but I would have to be in love with the figure on the board to not just rip it and re-glue. On solid wood I would fear eventual cracking. JMHO ;-)

[Tony Bilello]

By cutting a kerf he has substantially weakened the board. I would think that the only type of filler that would be strong enough to hold the joint together would be epoxy with a high density/high strength filler.

[David DeCristoforo]

Well I know there a lot of "Norm fans" around here but, IMMHO, that is the most ridiculous way to flatten a board I have ever heard and a nonsensical use of the kerfing technique.

[Myk Rian]

I also saw the show. It was pretty interesting how he did that. I believe he used an epoxy. Looked the same color as JB weld.

I thought for sure he was going to pick an armoire to copy, but instead opted for the easy table. :D

[Tony Bilello]

Well I know there a lot of "Norm fans" around here but, IMMHO, that is the most ridiculous way to flatten a board I have ever heard and a nonsensical use of the kerfing technique.

I was just being more delicate because I didn't want sound like I had professional jealousy.
BTW, I am not a Norm fan.

[David DeCristoforo]

"...I didn't want sound like I had professional jealousy..."

Wouldn't that be un-professional jealousy?

[Paul Greathouse]

I'll admit Norm does have a few unorthodox techniques but he is a darn sight more interesting to watch that those flowery-smowery design shows.

There's just something about watching two guys get all googly eyed about bedsheets and window coverings that makes my skin crawl. At least Norm is a mans-man type of guy.

[Mike Gager]

you guys that saw the show, did you notice towards the end when he had the table top on the bench how it was rocking back and forth? i thought maybe he had something under it but if he didnt, that thing wasnt even close to being flat

[James Harrison]

Instead of trying to make someone look bad why don't you just say I would have done it this way and then tell how you would have done it.
I don't think Norm is the world's greatest furniture maker but he sure has done more than most of us to promote woodworking.

[Myk Rian]

I would have made 2 kerf cuts in the wood instead of 1.

[Doug Shepard]

There's always the old fashioned method
http://www.sawmillcreek.org/showthread.php?t=57646

[Mike Gager]

Instead of trying to make someone look bad why don't you just say I would have done it this way and then tell how you would have done it.
I don't think Norm is the world's greatest furniture maker but he sure has done more than most of us to promote woodworking.

i wasnt trying to make him look bad, its a procedure i have never seen done before and was wondering (and pretty skeptical) if it actually worked

[Mike Gager]

There's always the old fashioned method
http://www.sawmillcreek.org/showthread.php?t=57646

his board was cupped a lot more then 3/16

he wouldnt have had any material left

[Scott Rollins]

Mike I noticed that; as well as the rather large gaps betweeb the apron and top...you could see light though it on TV. :eek:. But in perspective of trying to replicate 100 years of aging, a top with boards that wide will likely warp. I would let it be somewhat cupped and add some dents and scratches and a dull finish to make it look 100 yrs old.

[Dan Forman]

Very similar to a technique I saw demonstrated on Charles Neil's website for removing cup from a panel. Rather than filling with epoxy, he glued in a spline. He called it a technique of last resort. Here is the clip: Edit, see my post below for the link.

I saw the last part of the NYW show in question, wondered about the cup in the top, but it appeared that when he screwed the clips in to hold the top to the frame, it straightened out the cup pretty well.

Dan

[Myk Rian]

Dan;
That link points to a file on your desktop.

[Jim Kountz]

Yeah I dont know so much about the kerf cutting thing to flatten a board. There could be no edge treatment in the finished product unless you werent concerned about seeing the "body filler" repair to the kerf cut. I tried this in my steps that lead up to my shops 2nd floor. I had a 2x12 I was using for treads and one of them was cupped so I put a kerf down the middle and it flattened right out. It also cracked about a year later so the lesson is not to rely on this method for me.

[Clifford Mescher]

Instead of trying to make someone look bad why don't you just say I would have done it this way and then tell how you would have done it.
I don't think Norm is the world's greatest furniture maker but he sure has done more than most of us to promote woodworking.
I agree. An alternative method would suffice.Clifford.

[David DeCristoforo]

"...an alterative method would suffice..."

That is not what the OP asked for. He only asked what was thought about the "technique". I am sorry if my opinion of this is offensive to anyone (which it obviously is) but it's only my opinion and was offered as such. Obviously you are free to disagree.

[David Epperson]

I'm facing a very similar situation with a platter I'm planning to do from a wide board of Bradford Pear. The particular board was flitch cut not far from the outside of the tree, but only has 1/4 to 3/8" of cup to it. But it's also only about 4.5 quarters thick, and 20+" wide. What I'm thinking of doing is metting and redrying to flatten it a bit as has been described here, but to try and prevent future recupping, I've decided to run at leat 2 and possibly 3 dovetail grooves cross grain on what will be the bottom side of the platter. I may very well leave these crossmembers wide and make legs from them, something similar could be done under the tabletop. Just a thought.

[JohnMorgan of Lititz]

There's just something about watching two guys get all googly eyed about bedsheets and window coverings that makes my skin crawl. At least Norm is a mans-man type of guy.

Now that's hilarious and I couldn't agree more. That's almost quote worthy! Well put.

[Dan Forman]

OK, try this for the Charles Neil link.

YouTube - Part 2 - Uncup the Cup - WOODWORKING (http://www.youtube.com/watch?v=wijLDuPL4LA)


For some reason it doesn't start at the very beginning, but you will get the idea.

Dan

(file:///Users/danforman/Desktop/new%20woodworking/charles%20neil%20you%20tube/www.youtube.com:.webloc)

[Clifford Mescher]

OK, try this for the Charles Neil link.

YouTube - Part 2 - Uncup the Cup - WOODWORKING (http://www.youtube.com/watch?v=wijLDuPL4LA)


For some reason it doesn't start at the very beginning, but you will get the idea.

Dan

(file:///Users/danforman/Desktop/new%20woodworking/charles%20neil%20you%20tube/www.youtube.com:.webloc)
Thanks Dan. I have seen that video before and used that technique a couple of times. I just couldn't remember what site it was on. I'll have to put it in my "favorites" Clifford.

[Mark Hulette]

OK, try this for the Charles Neil link.

YouTube - Part 2 - Uncup the Cup - WOODWORKING (http://www.youtube.com/watch?v=wijLDuPL4LA)


For some reason it doesn't start at the very beginning, but you will get the idea.

Dan

(file:///Users/danforman/Desktop/new%20woodworking/charles%20neil%20you%20tube/www.youtube.com:.webloc)

Yup, Charles is a hoot. <unsolicited plug -on-> I got his Finishing Series and it is outstanding. I've been working wood for 12 years and this is easily the most comprehensive and understandable explanation of the black art of finishing I've found. And he covers just about everything, too!! <unsolicited plug -off-> I highly recommend it! Sorry to hijack this thread and yes, Normy used an epoxy.