grain!

[Walter Wolf G.]

Hi, as some of you may know, i'm doing wood boxes for a stair case. the box is made of 5 faces, my problem is the fifth face. The top and the bottom are with the same grain orientation, the sides with 1/4" plywood, and I was planing on making the fifth face of vertical grain, so when the wood expands, it will expand to the side as well with the top and bottom faces. but, since it's about 12" wide and 4" tall, it was VERY weak I couldn't even glue them because they broke. So, I don't know what to do, I think that if I do the 5th face with horizontal grain it will expand vertically so it will split the box apart. And well, plywood is no good because I only have 1/4" plywood and it's supposed to be 3/4" thick. What can I do? Maybe I could seal it so it won't move? I actually don't think I can prevent expansion so it might not work.

Walter

[Beechwood Chip]

My gut says floating panel. Cut a rabbet in all four sides of the end piece, and dadoes in the top, bottom and sides, and leave enough room for the panel to expand and contract in the dadoes.

Actually, my gut first said, "sliding dovetails in the top and bottom, and floating in the sides." That would lock things together pretty well, and still allow for wood movement.

Or, use horizontal grain and check the shrinkulator to see how much wood movement you'll get over 4". I'm thinking 4" is small enough that you don't need to worry about wood movement.

[PurpLev]

hold on - what's that about plywood? is this all made of plywood? or solid wood? if it's all plywood - there will be little to no movement at all, so there's nothing to worry about. if it's all solid wood - than glue it to the center of the top and bottom panels, and leave some room for expansion left and right. kinda hard to tell from the pictures.

[PaulMarcel]

I agree with both of them Couldn't tell from the pictures that the treads and bottoms were real oak vs plywood so I had Purp's question. Since it's real wood, I'd go for a panel like Beech suggested. Not sure what that will do to the look though. I presume you were expecting it to look solid.

If you glued hardwood on the 5th face, you'd need it to have vertical grain for the reasons you mentioned: it won't grow in the height of the plywood, but it will match the expansion of the hardwood tread/bottom.

Share more on what it's to look like and maybe we'll come up with other ideas.

Oh, coincidentally, today I'm refacing a stairway at a friend's house.

[Vic]

I agree about the approaches. You could use "keys" to attach a face. That would allow movement. But, I'd want the top to always remain flush...so, that's the point that would need to be figured out. I'd definitely need better pics before I could give a definitive answer. Can you shoot a few close ups? I need to see grain direction, etc.

[daninhim]

This is more a question than a suggestion...what if the 4 sides of the 5th piece were cut at a 45-degree bevel and mounted with the bevel on the inside...would that allow for enough expansion?

[Beechwood Chip]

It doesn't have to look like a panel. You can cut a rabbet in the outside face of the end piece, and keep everything flush even though it's floating. There will be a visible, but small, gap. There are spacers you can put in the dadoes to keep the gap equal on all sides.

[cosmocyb]

I go with Beechwood on this. I think the Rabbet is a good way to go. You know what they say, Keep it simple.

[iSawitFirst]

I'm with Beachwood too. The gap would give it another level of (contemporary) detail.