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
- 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!