Interior Barn Door

[Jonathan McCully]

I'm getting ready to prepare all of my panel boards for this project, and of course, I listen to a Wood Talk podcast that has me thinking about wood movement and want to make sure I've thought this through well. The comment that was made was that it's a negative thing to put solid wood boards within a solid wood frame, which is what I'm doing. I've planned to tongue and groove my panel boards together without gluing to allow for movement along the long grain. I also plan to tongue both long edges of the end boards of the panel to allow them to slot into a dado in the stiles. These boards will then be glued into the rails with dominos. Does this sound like it will be problematic from a movement standpoint or have I accounted for that adequately with my tongue and grooves?

[wtnhighlander]

Wood moves across the grain far more than along it. Concentrate your efforts on managing the joints where pieces are perpendicular to one another.

[Jonathan McCully]

15 minutes ago, wtnhighlander said:

Wood moves across the grain far more than along it. Concentrate your efforts on managing the joints where pieces are perpendicular to one another.

Makes sense. The perpendicular joint is the domino joining the panel board into the rail. Is gluing that domino into the mortise on the rail going to be problematic, even if I make those mortises slightly oversized? And do I need to cut my panel boards slightly undersized to allow for the movement of the rails into the panels? If so, how would I do that without it looking like a gap?

[Coop]

I may be corrected but: I would cut the tongues and grooves a little deeper than normal and leave a little space so they do not bottom out. This will allow for them to move laterally. I would also attach the panel boards to the rails with a single Domino in the center of the ends. Another option would be to cut tenons on the ends of your panel boards and grooves in your rails for them to ride in, with no glue or dominos. 

[treeslayer]

I’m with @Coop and wouldn’t glue them, if you’re concerned about them moving you could pin nail them thru the rails in the center of both dominoes 

[Jonathan McCully]

3 hours ago, Coop said:

I would also attach the panel boards to the rails with a single Domino in the center of the ends.

This was my plan. Can I glue the dominos in to the rails and panel boards or should I just leave them loose?

Sorry if these questions seem a bit elementary. I’m still trying to understand the best ways to design accounting for movement.

[Coop]

No glue should be fine. Your original design diagonal pieces. Will it still have those and if so, how will you attach those? Not that it has anything to do with this answer, just curious. 

[Jonathan McCully]

5 minutes ago, Coop said:

No glue should be fine.

Is that “no, glue should be fine” or “no glue should be fine” 

The diagonal should be 1/2” in thickness which allows it to rest on the panels flush with the frame. I was planning to use dominos to attach that into the frame as well, two on each end. I like the  dowel suggestion with a contrasting wood, but think I might use that on the half lap corners of the frame rather than on the diagonal. 
 

I really appreciate everyone’s advise on this project. I really like being able to try and design something myself and work through the challenges rather than just following a plan to the T. Not sure that seeking advice is the primary focus of these journal’s but hopefully someday I’ll be skilled enough to be able to just walk you through a project and maybe teach you something.

[wtnhighlander]

Looking back at your plan drawing, I see the t&g panels are vertical. If I were building this, I would glue the boards together to make a solid panel, and either cut a tongue around it to fit an oversized groove in the frame, typical raised panel style (no glue), or lay it into a rabbet from the back side. 

The reason I would avoid the single domino tenon per board idea is that each board is then free to cup, and the t&g on the edge won't do much to prevent that.  If you don't glue the t&g edges to each other, you risk shrinkage that could open random gaps in the panel. Seems easier to keep the shrinkage less obvious around the edge of the frame. I suspect that is the reason raised panels usually have a wide bevel or cove shape, as they would obscure the changing size of the panel better than a squared corder tongue would.

[Jonathan McCully]

11 minutes ago, wtnhighlander said:

Looking back at your plan drawing, I see the t&g panels are vertical. If I were building this, I would glue the boards together to make a solid panel, and either cut a tongue around it to fit an oversized groove in the frame, typical raised panel style (no glue), or lay it into a rabbet from the back side. 

The reason I would avoid the single domino tenon per board idea is that each board is then free to cup, and the t&g on the edge won't do much to prevent that.  If you don't glue the t&g edges to each other, you risk shrinkage that could open random gaps in the panel. Seems easier to keep the shrinkage less obvious around the edge of the frame. I suspect that is the reason raised panels usually have a wide bevel or cove shape, as they would obscure the changing size of the panel better than a squared corder tongue would.

I like the idea of gluing them up into a large panel rather than using the t&g and then perhaps putting a wide bevel on the insertion into the stiles with a deep groove. Been reading my Understanding Wood a bit tonight trying to understand this issue and that seems to be the way to go. Unfortunately, I’ve already cut most of these board to length to fit the frame, so a tongue on the end grain of the vertical boards or rabbeting to the back aren’t doable. Would having the boards as a large panel joined to the rails with dominos resist cupping where a single domino per board would not?

[wtnhighlander]

I see no reason a couple of dominoes on each board end wouldn't work. Just make the mortises a litte wider to allow for movement.

[Jonathan McCully]

It’s been a bit since I’ve updated this project, so this post will be a bit longer. I’ve gotten a decent amount of work done on this over the past few of weeks and am finally working to get the panels glued up. Based on the most recent discussion, I decided to glue up my panel boards into larger panels rather than putting a t&g on all of them. As the final width of the panel was 56” long, I decided to create 3 separate panels joined with a t&g joint which allowed me to learn the technique of making t&g as well as making it a bit easier to glue up the panels. To allow for tangential movement, I cut bevels on the long edges of the panels which are seated into a dado in the vertical stiles. The panels will eventually be joined into the rails with dominos. We’ve also decided to forgo the diagonals across the door as we felt that it took away from the overall visual appeal and made everything a bit too busy.

I first determined which boards would be receiving the tongues and which the grooves. I wanted to cut them all at the same time to limit variability.

Both tongues and grooves were cut on the router table (my first time using it). Panels were planed to final thickness of 5/8.” I used a 3/8” straight bit to form the groove and made it 3/8” deep. The tongues were cut with the same bit, centered on the board, but were cut to 1/4” to leave an additional 1/8” and keep the tongue from bottoming out in the groove.

My next step was to bevel the outermost panel boards. I wanted to put a 1 3/4” bevel on to allow for tangential wood movement so that if the wood experiences shrinking, it won’t leave a gap between the panel board and the stile. I started with a 1/4” deep dado on each of these boards followed by the bevel. The dado really just adds a bit of visual appeal and seems to be fairly common with frame and panel construction, based on what I’ve read. Bevels were then cleaned up with a block plane.

Next I cleaned up some of the ends, rejointed a few of the boards, and cut the dados in the stiles, all prior to a dry fit.

Now, I’m in the process of glueing up the panels after which I’ll cut the mortises for the dominos and finish sand the entire door. Hope to finish most of this by the end of the week.