Joints to handle wood movement?

[heathicus]

I'm in the process of building a doll house for my girls' Barbies. (Nothing elaborate, but something rather simple similar to this).

My stock is the leftover pine I had from the wood my dad gave me to build my shop with. None of the boards I had left were wide enough, so I glued up panels with as many as 3 boards. All of the panels have been planed, jointed, glued up, planed again, cut to width and to length over the last few weekends.

The wood is not kiln dried. It's just been stacked behind my shop for about a year and a half now. As I'm working with it, I can tell it's still a bit "wet" so I'm expecting some movement once it goes inside and dries more.

So I'm concerned about that movement. I don't want any splits from joinery that doesn't allow the contraction. But I want it to be solid as well. Every panel is aligned so that the majority of the movement will be from front of the house to the back of the house. There shouldn't be as much up/down or left/right movement. But can I count on each board drying and moving at the same rate as the one it's joined to?

What is the best joinery to accommodate this expected movement (shrinkage)? I don't have a Kreg pocket hole jig. I don't have a biscuit joiner. I have a few of the pins and cam locks I've taken off of discarded particle board furniture. Would they be good? They would also allow for easier disassembly and storage once the girls grow out of it.

[heathicus]

No suggestions?

[nuhobby]

I wasn't sure I understood the exact question you had.... so my info here may not hit what you're after.

Here's a pine 'secretary' I made from old pine boards from a dumpster. Things I can note are:

- All the long-grain glue-joints were straightforward and durable. I never much thought about that direction of grain having expansion/contraction differences.
- The very large glued-up panels such as the writing surface, I knew would want to bow. So I've got some thin steel rails inset into them, serving as "breadboard ends". (Steel rails re-purposed from that same dumpster.)
- Where my shelves are installed, each end of each shelf has 3 dowels holding it in place. It's all held up well seasonally for 3 years now. If you're making something similar, it ought to do fine I'd think .


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[heathicus]

Thanks, Chris. The construction of your secretary isn't too different from what I'm doing. Here's a pic of the doll house laying on its back (the right angle clamps are on the bottom of the house - the angled cuts will be the top).



Nothing is glued, screwed, or attached in any way. They're just standing up.

The only place I will have a cross-grain joint would be at the top. I don't have the parts showing it in the picture above, but the top of the house will be a storage area. The slanted "roof" (outlined in blue in the pic below) will be hinged and can be raised to open the storage compartment. The front of that compartment will be a cross-grain joint.



So my question is how to join the parts and accommodate the expected wood movement? Or, with all the wood moving in the same direction, is it even a problem to anticipate?

[swampgator]

When you stated you did NOT have a biscuit joiner, my first thought was to tilt the table to get the holes just like a Kregg clamp.

Another way that I like to do is rabbet/dado 3/8" where the boards will join. Doweling can look cool too.

Corrected my first statment.

[nuhobby]

Hi Heath,

I think 95% of your joints will have no conflicts and you can fasten however suits you. For the slanted "lid", that free-hinged plank may want to bow with humidity changes, so some perpendicular elements (e.g., breadboard ends, or even some simple rigid beams on the lid's underside) fastened with a bit of elongated slots would be great there.
That just leaves the vertical front cover piece as a cross-grain joint. Probably anything akin to fasteners-in-elongated-holes, or long tenons in a groove, would give you plenty of breathing room.
Your girls will love that piece!

[BuckeyeDennis]

Since wood is pretty stable in the length dimension along the grain, the only potential problem with expansion I see for your project is the backing. If you use a glued-up panel for that, you will need to allow for expansion cross-grain, like you would with a tabletop. I understand that plywood is stable in both dimensions, so do I believe that a plywood backing could be fastened rigidly.

[bffulgham]

Since wood is pretty stable in the length dimension along the grain, the only potential problem with expansion I see for your project is the backing. If you use a glued-up panel for that, you will need to allow for expansion cross-grain, like you would with a tabletop. I understand that plywood is stable in both dimensions, so do I believe that a plywood backing could be fastened rigidly.

I agree with BuckeyeDennis on the back....that's a wide piece of solid wood. You could try attaching it with screws...no glue. Maybe a tight fitting screw in the center and elongating the screw holes on the back board as you work to each edge (working across the grain) to allow expansion/contraction. If you haven't already created a panel for the back, yes, you can solidly attach a piece of plywood to for the back....it adds a lot of rigidity and strength.

The other cross-grain issue I see is with the front rail at the top for the storage compartment. You could screw something like a vertical 3/4" x 3/4" block in the front corners tightly screwed to the carcass sides and the elongated holes in the block to attach the front rail.

Instead of planning to take it apart and store it when the girls outgrow the Barbie thing.....convert it to a book case

[heathicus]

Thanks for the comments and suggestions! I do feel a lot more confident going forward now.

So I'm going to plan on dadoes on the sides for the horizontal shelves ("floors"), reinforced with through dowels in from the sides. Dowels only for the inside dividers ("walls"). Trimmed and sanded flush that will give me no screw holes to try to hide with wood filler. Follow bffulgham's suggestion for the front rail at the top and nuhobby's suggestion to keep the lid from warping.

The back panel will be thin plywood.

The whole thing will be painted except the "floors" which I'll stain. Fabric scraps from my mother-in-law will serve as "wallpaper" for each room. I might make a staircase to go between floors, and some fake dormer windows for the roof.

[bffulgham]

Thanks for the comments and suggestions! I do feel a lot more confident going forward now.

So I'm going to plan on dadoes on the sides for the horizontal shelves ("floors"), reinforced with through dowels in from the sides. Dowels only for the inside dividers ("walls"). Trimmed and sanded flush that will give me no screw holes to try to hide with wood filler. Follow bffulgham's suggestion for the front rail at the top and nuhobby's suggestion to keep the lid from warping.

The back panel will be thin plywood.

The whole thing will be painted except the "floors" which I'll stain. Fabric scraps from my mother-in-law will serve as "wallpaper" for each room. I might make a staircase to go between floors, and some fake dormer windows for the roof.

I think you will be very happy with the plywood back. The back on my pantry is only 1/4" ply attached with glue and 18ga brads, but it really stabilized that monster and it's 36" x 84" x 24"
You are going to make some little girls VERY happy. Way to go Dad!

Bud