Intro: Simple Marking Gauge for Non-square Edges
I am currently building an Optimist sailing dinghy for my son (similar to this 'ible) and needed a marking gauge to mark off 50mm distance off the bottom edges of the hull. My standard marking gauges all failed because they cannot cope with angles higher than 90 degrees. Working this way would create rather random lines.
So I set out to make myself a quick & simple solution based on 2 short lengths of wooden strips from a decomissioned window blind (jalousie ... IKEA Lindmon). I like these strips as they are very handy for a lot of purposes in the workshop. They can be easily broken over the edge of the workbench, and I am using them
- as protection layers for clamps and vises
- as rulers
- as flat splines
and lately as marking gauge ... let's see.
Step 1: Marking, Cutting, Edge Preparation
- Measure gauge datum - in my case 50mm - from the hole in one of the strips
- write the datum on one surface - from now on called "datum surface"
- draw a perpendicular line on datum surface and cut - I used a chisel here, scissors or back saw are equally suited to get a "datum edge"
- grind down the back side of the datum edge to a sharp angle - the angle itself is not critical, but maintain the edge of the datum surface just cut so nicely.
- cut to convenient length the other end of the strip
- prepare another strip of convenient length with one side precisely cut perpendicular and grinded as described in 3 & 4 above
Step 2: Glueing
- Take a length of adhesive tape and place it - glue side up - on a flat suface
- position your gauge with datum side down on the tape (as you can see in 1st picture I almost positioned the marking hole across the tape - not the most brilliant idea - but I realized that soon enough)
- position the other piece next to the gauge piece so that edges just touch
- if tape is wider than strips, cut out triangles where the two pieces meet - I used my chisel here - and wrap tape around the edges
Step 3: Using
- Fold the gauge around the edge you want to mark - with datum piece on the surface to be marked
- mark surface through the hole
- advance and repeat
I hope someone will enjoy this idea as much as I enjoyed building, using and documenting this gauge (and yes it's my first 'ible)