Clamps for Boxes

Paul Douglass

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S E Washington State
I curious what you who make all the pretty boxes, how do you clamp them after glueing? I've been looking at some different types of 90' corner clamps, but I do not know how well they work.

Appreciate any input.
 
Another vote for tape, especially for mitered corners. I've typically used clear packing tape but blue painter's tape would also work. Here's a quick sketch of how the sides of the box are laid out and taped together before adding glue and folding it all into a box shape. As long as your 45º miters are dead on, you'll get nice tight joints with this method:

Box%20Glue-Up.jpg


I do have some 90º angle clamps made for things like picture frames, but have never been impressed with the results they give me, so they've gone unused for years.
 
When I used to make a lot of boxes I used biscuits to reinforce and align the corners. I still have at least 4 of the small Ryobi biscuit joiners that use the miniature biscuits that can be inserted in wood as thin as 3/8". The biscuits did a great job of aligning the corners but I still needed something to clamp it all together while the glue dried. I always applied painter's tape along both sides of the miters to catch glue squeeze out which inevitably happened.

For that I used Wolfcraft and Pony box clamps. I have no idea if they are still available. They work great and apply pressure where it is needed. Depending on the size of the box I could get away with just one but even for large boxes I seldom needed more than two, one at the top and one at the bottom.

box clamp.jpgbox clamp 2.jpg
 
I read someplace that the thinner the glue line is the better the joint is since glue itself has no strength to speak of. Now I realize that painters tape will apply an enormous amount of pressure to a joint, it won't come close to pressure applied by mechanical means. So for box joints (finger joints) and dovetail joints I use Bessey bar clamps. For miter joints I use the Bessey strap clamp (about $35.00 or so). Also I reinforce the miter joint (FF biscuits, splines) since by itself it is very weak.

DKT
 
I read someplace that the thinner the glue line is the better the joint is since glue itself has no strength to speak of. Now I realize that painters tape will apply an enormous amount of pressure to a joint, it won't come close to pressure applied by mechanical means. So for box joints (finger joints) and dovetail joints I use Bessey bar clamps. For miter joints I use the Bessey strap clamp (about $35.00 or so). Also I reinforce the miter joint (FF biscuits, splines) since by itself it is very weak.

DKT

You are correct about thin glue joints, but especially on thin-walled boxes (let's say 3/8" to 1/2"), tape can exert more than enough pressure to create a strong, thin joint. I've never had the joints on a mitered box fail using tape. Mechanical clamps are capable of actually exerting too much force, and can end up squeezing too much of the glue out of the joint, causing a weaker joint in the end. Of course, mechanical clamps will work, but you must resist the urge to overtighten them. The accuracy of your cuts, and a thin even layer of glue on both surfaces are more important in creating a strong joint than romping down on the clamps.
 
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