# Cross Grain Joint



## jcwalleye (Dec 26, 2009)

It's been a while since I lasted posted on Lumberjacks and hope you're willing to offer some opinions.

I'm building a simple riser made of 9/16" red oak. The base and top of the riser will be a glued up panel 18" deep. I'd like to attach the sides, and a center divider to the top and bottom with a dado or rabbit, glue, and brads. It's a classic cross grain dilemma. My question is 'how much expansion should I expect, considering that the oak is all quarter sawn? Is it likely to blow apart with seasonal movements? I live in a very arid climate.

Here is a picture of the materials I plan to use and showing the cross grain.










Can you suggest another joint that is simple yet somewhat durable? Worst case scenario is that I'll glue up another panel and cut that across the grain, effectively matching the sides to the base and top.

Thanks much. Joe.


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## bondogaposis (Dec 18, 2011)

What's a "riser"?


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## jcwalleye (Dec 26, 2009)

Just a small shelf to set a flat screen TV on. Raise it 6" or so. It'll have a top, bottom, 2 sides, center divider, maybe a back to prevent racking


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## bondogaposis (Dec 18, 2011)

Oh, I thought you were building stairs, and the picture made no sense for that. Being 18" deep you are going to get some wood movement even with 1/4 sawn. If you glue the top down it might split but will still work as a shelf. If you skip the glue, the brads will flex and allow movement with out stressing the top. You could glue the front edge and let the movement go to the back.


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## jcwalleye (Dec 26, 2009)

Good ideas. Glue and brads at the front, brads only at the back?

It's for a friend and he's not going to be fragile with it. He should be able to grab it anywhere and not worry about the unit's strength.

Other thoughts, tongue and groove for the top and bottom (lot of work). Sliding dovetail (too complicated).


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## Loren (May 30, 2008)

I would make the sides and dividers with
the grain going the other way.

I expect the 18" top would move about 3/16" 
in quartersawn oak. As I recall flatsawn 
moves about 1/4" per 12" span and quartersawn
half that.


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## jcwalleye (Dec 26, 2009)

Great info Loren. That's probably the way to go. Thanx


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## Lazyman (Aug 8, 2014)

So you are basically making a narrow box with a divider that is laying on its side, right?

Loren, why wouldn't you want the grain on the vertical pieces, ends and dividers to be the same as the horizontal? It seems like if they we all oriented the same way, they would be more likely to move together? Maybe I don't understand what you mean.

Also, I would think you would want the glue in the middle instead of close to the front or back . Similar to how you attach breadboard table ends. That way you only get half the movement at the edges? Again, maybe I'm missing something?


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## Loren (May 30, 2008)

> Loren, why wouldn t you want the grain on the vertical pieces, ends and dividers to be the same as the horizontal? It seems like if they we all oriented the same way, they would be more likely to move together? Maybe I don t understand what you mean.
> 
> - Lazyman


I'm saying to do what you're saying I think.

What the OP was wanting to do was the sort of
thing where you really have to use something
like sliding dovetails for it to work.


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## wormil (Nov 19, 2011)

If the pieces are oriented correctly, there will be no cross grain joints.


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## jerryminer (Jun 15, 2014)

> If the pieces are oriented correctly, there will be no cross grain joints.
> 
> - Rick_M


Right. I agree. I think Loren and Lazyman are saying the same thing. Top and bottom grain running left-to right. Vertical pieces grain running top-to- bottom. (all parts are 18" glue-ups)


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## HorizontalMike (Jun 3, 2010)

> It s been a while since I lasted posted on Lumberjacks and hope you re willing to offer some opinions.
> 
> I m building a simple riser made of 9/16" red oak. The base and top of the riser will be a glued up panel 18" deep. *I d like to attach the sides, and a center divider to the top and bottom with a dado or rabbit, glue, and brads.* It s a classic cross grain dilemma. My question is how much expansion should I expect, considering that the oak is all quarter sawn? Is it likely to blow apart with seasonal movements? I live in a very arid climate.
> ...[snip]...
> ...


IMO, SKIP the glue portion and let the divider slide(shrink/swell) in the dado. Attach the sides and divider with brads only, and not too many of them. You want to allow that movement within limits.

The only other option I see would be to use veneered plywood, because that would minimize/eliminate shrink/swell and any cross-grain issues.


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## jerryminer (Jun 15, 2014)

Brads only, without glue, would be a problem if this thing is handled roughly-like picking it up from the top only, with a heavy object or two sitting on the bottom. You'd be pulling the brads out as you lift.

But if it just sits still with weight on top, it'll be fine. I would definitely put some kind of back in it.


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## jcwalleye (Dec 26, 2009)

Thanks all. Loren was first to suggest what I actually ended up doing, reorienting the side's grain to match the top and bottom. That the top could move up to 3/16" was compelling. And no joint, other than a sliding dovetail, could offer much strength and survive the cross grain expansion. I'd hoped there was a simple one, but couldn't come up with it. Thanks again.


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## bbasiaga (Dec 8, 2012)

In the TV stand in my projects list I just used a pin in the back, so the whole riser was mechanically free of the table top, but still held in place so it didn't move when moving the TV. So far, so good.

Brian


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