Mitered box questions

[Scott H]

Working on a small cherry box with mitered sides and a top/bottom that sit in grooves. I thought I would double check some stuff before I started gluing anything together. The box is 5-1/4 long x 3-1/4" wide and will be about 2-1/8" tall, with surface mount hinges, and thinking maybe putting a tiny magnet in the top to make a magnetic catch. Planning on a shellac finish. I'm planning to glue it up as a single unit, using tape as the "clamps", and saw the top off to separate it when the glue has cured. The purpose of the box is to hold a friend's tarot card deck so it is not probably going to be getting super rough use.

Some of the things I'm trying to sort out, I suspect this is all really basic boxmaking stuff...

• For a box this size would you leave the top/bottom floating or would you glue it? The top/bottom stock is 1/8" thick quartersawn if it helps, about 3" wide across the grain.
• I'm worried about getting glue squeeze out that interferes with the finish or unintentionally locks the top/bottom in place. Also, I'm worried since shellac is a film finish, if I finish it after assembly the shellac would weakly lock the top/bottom in place and make an unsightly finish crack or gap if it does move. Can anyone suggest order of operations and any tips for glue up and finishing? In the past I have just mummified the project in blue tape to avoid squeeze out problems but I don't think it will work well here, especially if I do a floating top.
• Do you think titebond 3 with sizing applied to the miters first is enough or should I do feathered miters to reinforce the sides? I could do feathered miters decently well I think, just trying to keep this from getting unnecessarily complex. The sides are 1/4" thick if that matters.

I probably have more minor questions that will come to me later but those are the big ones. Thanks in advance for your help.

 

[Wiley's Woodworks]

1/4" thick sides leaves you almost no surface area to glue together on the miter hypotenuse. It will break apart the first time it hits the floor. You're going to need some kind of interlocking joinery to hold it together. Since you're going to glue it up as a one piece box and cut off the top section, box joints may be the easiest. Every recipe box you've ever seen uses box joints. The walls are so thin a feather miter joint--aka spline joint--won't add much strength. After you clean out the insides of the corners there's just not that much wood in the spline.

Regarding finishing: Cut the lid off the box, finish it in 2 pieces, then mount the hinges.

 

[NYTransplant]

Working on a small cherry box with mitered sides and a top/bottom that sit in grooves. I thought I would double check some stuff before I started gluing anything together. The box is 5-1/4 long x 3-1/4" wide and will be about 2-1/8" tall, with surface mount hinges, and thinking maybe putting a tiny magnet in the top to make a magnetic catch. Planning on a shellac finish. I'm planning to glue it up as a single unit, using tape as the "clamps", and saw the top off to separate it when the glue has cured. The purpose of the box is to hold a friend's tarot card deck so it is not probably going to be getting super rough use.

Some of the things I'm trying to sort out, I suspect this is all really basic boxmaking stuff...

• For a box this size would you leave the top/bottom floating or would you glue it? The top/bottom stock is 1/8" thick quartersawn if it helps, about 3" wide across the grain.
• I'm worried about getting glue squeeze out that interferes with the finish or unintentionally locks the top/bottom in place. Also, I'm worried since shellac is a film finish, if I finish it after assembly the shellac would weakly lock the top/bottom in place and make an unsightly finish crack or gap if it does move. Can anyone suggest order of operations and any tips for glue up and finishing? In the past I have just mummified the project in blue tape to avoid squeeze out problems but I don't think it will work well here, especially if I do a floating top.
• Do you think titebond 3 with sizing applied to the miters first is enough or should I do feathered miters to reinforce the sides? I could do feathered miters decently well I think, just trying to keep this from getting unnecessarily complex. The sides are 1/4" thick if that matters.

I probably have more minor questions that will come to me later but those are the big ones. Thanks in advance for your help.

Unless the panels are loose and move freely in the grooves, I'd leave them floating. I've also done it where I've put a single bead of glue at the center of each groove. It allows the panel to move, even though it's "locked in". The other option is to use spaceballs (not the movie ) they are flexible balls that keep the panel centered in the groove yet allow it to move. I haven't used them, but will probably try them on my next box.

The last box I made, I sanded the lid to less than 1/8" thick and laminated it to 3mm plywood for stability. It was not captured in a groove though, it was dropped into a rabbet, so I needed it to to stay as stable as possible to avoid a gap.

I've done a cherry box nearly identical to yours and have not had any issues with the shellac creating a line due to wood movement. It's only been a few months though, but zero issues thus far.

I've since switched to Odie's oil because it doesn't build up a film. I typically finish all the parts for the interior (other than the glued surfaces) of the box before assembly. The finish is matte compared to shellac, but I believe you can add paste wax over the finish to give it a glossier surface. I'd expect this would be a better finish to use if you wanted to finish the top/bottom panels before assembly.

Not sure about the last question. I use splines to reinforce the miter joints.

I'm no expert by any means. I'm still learning boxmaking myself, but thought I'd share my limited experience.

Tim

 

[Scott H]

1/4" thick sides leaves you almost no surface area to glue together on the miter hypotenuse. It will break apart the first time it hits the floor. You're going to need some kind of interlocking joinery to hold it together. Since you're going to glue it up as a one piece box and cut off the top section, box joints may be the easiest. Every recipe box you've ever seen uses box joints. The walls are so thin a feather miter joint--aka spline joint--won't add much strength. After you clean out the insides of the corners there's just not that much wood in the spline.

Since I have a minimum interior dimension to hit and the sides are already mitered do you recommend I throw out the sides and make new ones? If I am doing that anyway is there a thickness that a feather miter would begin to be acceptable (3/8", 1/2", ...?)

 

[Mike Davis]

1/4 inch thick white oak pencil box dovetailed on all sides over 10 years ago.
Made it through 6 years of school without a ding.

 

[Wiley's Woodworks]

I didn't realize you had already cut the miter corners, and you can't cut them off and start over. Such is life. If you're a gambler, here's a hack. Mix up Titebond III and water at ~ 75/25, i.e. "thin" the glue. Spread it on the miter edges and push it into the end grain with your fingertip. Wait 20 minutes or until the glue is tacky but not dried. Spread 2nd coat of glue as normal and form up the box. Your tape up method for clamping will do. Clean out insides of corners using miter cut plastic drinking straw hack. Let dry overnight before handling. The joint will be stronger than an ordinary end grain glue up, but I won't vouch for it surviving hitting the floor from table top height. Ya pays your money and takes your chances.

 

[JohnnyR]

Given the thin sides I wouldn't use hinges. If you cut halfway thru the inside of each side, assemble and then cut halfway thru the outside, one kerf width lower, you've got a removable top which would be fine for this use. Of course, you'll lose an 1/8" of height. Either way I'd finish at least the inside of the box and tape it before assembly which will help with squeeze out.

 

[JohnnyR]

One other thing.... I got the impression that the box will just fit the tarot cards. Therefore, no room for fingertips to remove the cards. If you tip the box over you may have a vacuum problem getting the last card out. If so, I'd drill a small hole in the bottom so you could blow it out.

 

[NYTransplant]

Here is an interesting video proving end grain joints are stronger than long grain joints. The experiments are well thought out and executed using consistent methods, and equipment. As an engineer, it's intriguing.

Note that these tests are done on a butt joint and not a miter joint, though the bending forces acting on the joint will be related when a miter is stressed along the vertical edge. A corner drop will respond differently.

 

[ssmith]

Don't want to get too far off-topic but VERY interesting and credible video - the author knows what he's doing.

Can't help but wonder if the stigma of end-grain joint weakness is also because some woodworkers may not use enough glue? Since end grain will absorb a lot more than side grain, that could starve the joint itself and lead to weakness.

 

[Cuprousworks]

I've used epoxy on box miters without hidden or decorative splines and haven't experienced a failure. But I haven't tried the drop to the floor test...

Mike
Chapel Hill

 

[NYTransplant]

Don't want to get too far off-topic but VERY interesting and credible video - the author knows what he's doing.

Can't help but wonder if the stigma of end-grain joint weakness is also because some woodworkers may not use enough glue? Since end grain will absorb a lot more than side grain, that could starve the joint itself and lead to weakness.

One thing mentioned in the video are advancements in glues. Perhaps the stigma of end grain joints stems from older glues.

It reminds me of old timers warning you should never put a car battery on a concrete floor because it will discharge. In the days of rubber encased batteries, this was likely true. Heck, when winterizing my vehicles, I never put a battery on a floor when I was younger. I always put a couple 2x4s under it. With advancements in plastic casings, that rule no longer applies.

 

[Scott H]

Thank you for the suggestions and thoughts everyone. I guess I am in the process of deciding if I want to keep working with these sides or just resaw out some new 3/8" sides. On the one hand if I keep going forward it will get me more experience with glue up, finishing, etc that I could then use on later sturdier boxes. On the other hand I am doing the resawing and planing/final thicknessing for all of the parts by hand due to having mostly hand tools so I am reluctant to throw the time I spent on the top/bottom away on less than ideal box sides.

@JohnnyR thank you for the design thoughts, the box is slightly larger than the cards by about 1/8" on the width and height which I imagine is enough to prevent vacuum issues but not enough to cut off the miters + still fit the cards.

 

[NYTransplant]

@Scott H, I wrote up an article on building a box joint jig recently and your post had me thinking about the strength of different joints. In the intro, I compared four corner joints: Miter, Splined Miter, Box, and Dovetail in surface area and mechanical strength. Not super-scientific, but hopefully informational.

The Modular Crosscut Sled: A Simple Box Joint Jig

 

[Robert166]

Thank you for the suggestions and thoughts everyone. I guess I am in the process of deciding if I want to keep working with these sides or just resaw out some new 3/8" sides. On the one hand if I keep going forward it will get me more experience with glue up, finishing, etc that I could then use on later sturdier boxes. On the other hand I am doing the resawing and planing/final thicknessing for all of the parts by hand due to having mostly hand tools so I am reluctant to throw the time I spent on the top/bottom away on less than ideal box sides.

@JohnnyR thank you for the design thoughts, the box is slightly larger than the cards by about 1/8" on the width and height which I imagine is enough to prevent vacuum issues but not enough to cut off the miters + still fit the cards.

As the rookie in the group, I like it! Don't toss it! Make a another!

 

[avikb]

@Scott H, I wrote up an article on building a box joint jig recently and your post had me thinking about the strength of different joints. In the intro, I compared four corner joints: Miter, Splined Miter, Box, and Dovetail in surface area and mechanical strength. Not super-scientific, but hopefully informational.

The Modular Crosscut Sled: A Simple Box Joint Jig

That looks pretty straight forward, thanks!

 

[Hmerkle]

@Scott H, I wrote up an article on building a box joint jig recently and your post had me thinking about the strength of different joints. In the intro, I compared four corner joints: Miter, Splined Miter, Box, and Dovetail in surface area and mechanical strength. Not super-scientific, but hopefully informational.

The Modular Crosscut Sled: A Simple Box Joint Jig

Tim,
Would you mind if we put your box joint jig article in our references? (If it isn't already)

 

[NYTransplant]

Tim,
Would you mind if we put your box joint jig article in our references? (If it isn't already)

Sure Hank. Feel free to copy & paste if that works.