Clamping at ANY Angle





Introduction: Clamping at ANY Angle

Clamps are a woodworker's best friend... until you need to clamp two non-parallel surfaces. There are specialty clamps for picture frames, cabinet making, and other 90 degree applications but you'll also find yourself facing a 45 degree or 30 degree angle every so often.

When faced with a 45 degree angle, if you're like me, you'll first try to use a bar clamp with a pivoting head. Friction will allow the clamp to work if your surfaces are close to parallel or if your wood is rather rough. Thinking yourself rather clever you'll then attempt a glue-up and the now-greatly-slicker surfaces will slide all over when you try to tighten the clamp.

A scrap piece of wood, a few basic tools, and 5 minutes are all you need to create a custom v-block for securely clamping any angle!

Step 1: Grab a Scrap Piece of Wood and a Piece of Paper

You'll need-

  • A scrap piece of wood (mine was approximatly 1.5" x .75" by 1 ft)
  • A piece of paper
  • A pencil
  • A saw


  • Power Drill

Step 2: Create a 45 Degree Angle

Fold the piece of paper to form a 45 degree angle. Lift one corner along the short edge of the paper and bring it to the opposite long edge, lining up the short edge of the paper with the long edge.

Note: This is a great trick to quickly check angles around your workshop. Often a folded piece of paper is better than a metal angle when checking the alignment angle of a blade (which might be knicked) or reaching in between delicate components.

Step 3: Mark a 90 Degree V

Line up one edge of your 45 degree angle with the bottom edge of the scrap board. Mark with a pencil along the folded edge (you could also use the other edge of the 45 degree angle but the pencil will travel better against the fold). Flip your template over horizontally and mark a second line.

Make sure that the intersection point between your first and second line is approximately in the center of your scrap board. If the V shape is too deep, your block might split later under clamping pressure.

Step 4: Mark the Edge

Draw a straight line so the V shape will be approximately in the middle of the final block. If you love exact angles, you can use the corner of your piece of paper to draw a vertical line 90 degrees from the bottom edge of the scrap board.

Step 5: Optional: Drill at the Intersection

Use a drill to make a hole at the intersection of your two 45 degree lines. I used a 3/16" drill bit but you can use whatever looks proportional to you. The hole creates clearance space at the intersection of the V block and will help protect delicate corners (especially mitered corners that are slightly off).

Step 6: Cut Out the V and Cut Off the V Block

Use a saw to cut off the section of your scrap lumber that will become the v block. Mine ended up being a little over 3 inches but yours will vary depending on the depth of your V and desired angle. Next, cut each side of the v shape. Be sure to keep your blade on the inside of your pencil lines to make the drilled hole as effective as possible.

Step 7: Clamp at 45 Degrees! (or Any Other Angle)

Clean up the edges of your v block with some sandpaper and clamp away!

You can use this technique to make a custom v block to clamp against any angle with a little math (or a protractor).
I'd love to see your results if this helped you out!

Happy making!



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Been thinking about making something like this for a while. How does it hold up when clamping a diagonal that long? Doesn't it spread the walls apart anyway?

You can simply make a larger version off her design, so it has more 'backing' on it. Basically, if the backing goes up higher, you'll have more of a plane to brace against. Good for larger projects or for wood that is flexible (which would require a rigid backing).

As of now the backing is a bit low, but that is all that she needed in this case. Her cuts of wood are straight, rigid, and she double-checked with a square.

Just add another clamp on the diagonal to keep it all together.

Clamps on clamps on clamps! :)

Of course, exactly why there are never enough clamps in the workshop!

marteen1 - sure, yet then there's the thing of stock size needed to cut such a thing. I think I have one idea in mind though - a bigger version with steps for clamsp should work.

Great idea! Now, why didn't I think of that? Thanks!

In regular woodworking, you secure the diagonal piece with glue plus 18 ga nailgun. If you clamp a diagonal into a 90º, you have to be spreading the angle. The angle blocks are great but not in this construction.

You think so? This is the perfect time for the angle blocks.

The vertical wood piece would have to bend before that angle would spread. And if it was to bend, then your clamping it too hard.

And it strikes me that any but the lightest clamping will bend the 90º to 93, 95, 97º.. Keep a good square on the angle and give it a try. You might also create a double hooked piece that prevents spreading. Could also place the rt-angle assembly facedown on a piece of plywood with wood strips hard against both sides so it can't spread.