Friday, July 22, 2016

Making a Panel Gauge - Part 2

I've never been good with metal work.  I thought about buying an X-acto knife blade to use for the cutter in this panel gauge, but I decided to make a cutter from a piece of one of my thicker (0.039") card scrapers.  I hope the metal is good enough to hold an edge.
Hacksawed a bit over 5/16"
Filed it to a width of 5/16"
Then filed one end to a point and started putting an edge on one side
And got the final profile - all with a straight single-cut file
I used an off-cut from the stem of the gauge to practice mortising for the cutter and wedge.  This turned out to be very important.  In the following picture, the mortise on the far right was my first attempt.
First mortise at right, final practice try in center
I was a little worried about blowing out the wood to the right of the mortise when chopping and that's exactly what happened.
Can you see the end grain protruding?
So I decided to first drill out the hole with a 1/4" drill bit and then pare away the waste with a 1/4" chisel.  The mortise is 5/16" wide.  On the bottom it is 5/16" long and on the top it is 13/32" long.  The wall closest to the end of the stem is straight and the other wall is angled.  I took my time and pared carefully.

When it was time for the real thing I marked very carefully, drilled the hole, and pared away.  BTW, I started the mortise about 3/4" away from the end of the stem.
Mortise layout on bottom
And on top
Drilled from both sides to avoid blowout
Chiseled out the waste
Used an auxilliary light to see the inside better.  See the hump in the middle?
I pared away until a chisel laid on the wall was flush with top and bottom edges.  With the mortise cut it was time to fit a wedge.  I had a small oak scrap, already at 5/16" width and cut the angle to get an approximate fit.
Tight fit on bottom ...
But not so good on top (mind the gap!)
I tweaked the wedge until I got a tight fit top and bottom.  Then I trimmed the wedge and the back end of the cutter to get the lengths I wanted.
This cutter isn't going anywhere!
There are a couple important points about this picture.  First, the wedge sticks out of the bottom of the stem a little bit.  This allows you to overhang the cutter but not the wedge at the end of the bench.  A light tap loosens the wedge.
Tapping the wedge to loosen the cutter
On the other side, the wedge sticks up higher than the cutter so you can tap it to tighten the cutter in place.
Tapping the wedge to tighten the cutter
For finishing, I gave all parts two coats of shellac.  Then the stock and stem (except for the side that opposes the wedge) got a coat of wax.  What a difference in how the stem slides in the mortise!  No wax on the wedges so they will hold better.
Shellac drying (how exciting!)
In use, to tighten or loosen the stem at a certain location on the stock, it takes just a tap on the bench.  But it really holds TIGHT.  It's no wonder wedges were such an integral part of woodworking shops for centuries (and still are in some shops).
Tightening the wedge
Loosening the wedge
In use, the rabbet cut at the bottom of the stock will slide along the straight edge of a board.
Slides nice after waxing
And the requisite glamour shot:
The finished product
I almost forgot - I drilled a 9/32" hole in the other end of the stem for a tight fit with a pencil when I want a pencil line instead of a knife line.  If I ever use skinnier pencils or if the fit gets loose I'll put a screw in from the side to tighten it down.
Turn the stem around and use pencil for a non-knifed line
And there you have it.  Another "to-do" list item done.  Finally!  Now I have to wonder how and where to store this ...

Edit: I'd appreciate it if anybody can recommend whether or not I should harden and temper the cutter.  Thanks.


  1. Nice looking panel gauge. It took me 3 tries before I got my done. Mine is made of maple and has a 3 foot beam. It doesn't get a lot of use. As an aside, McMaster-Carr sells a 1/16" thick brass angle iron 3/4 x 3/4. Lining the rabbet with it will extend the life of it and keep it square longer.

    1. Hey Ralph - like you, I don't think this gauge will get too much use. But after some use if I think it is wearing I'll add the brass angle. Thanks for the tip.

  2. Great looking gauge! Mine has the same setup for a pencil. The pencil sees far more use than the marking pin.
    Again, nicely done. Enjoy!

    1. Thanks Greg. It was a quick and fun project. Time will tell whether I use the cutter or pencil more.

  3. Nice looking gauge. It has also been on my hit parade for a while, but was never sure how long to make it. Last week found an antique one while shopping for chocolate :-) Look pretty much like yours except the point is simply set in like a pin gauge and there is not much of a nib left, would need replacing. I intent to make two duplicates for my sons. How long is your beam?

    As far as hardening/tempering the cutter, the short answer is NO if you don't mind sharpening more often. Its not something used every day so should last a while. YES if it does not last long (too soft) however, being made from a piece of card scraper, I suspect it is already hardened enough

    Bob and Rudy

    1. Oh, more important than worry about the cutter would be the brass strip, like Ralph said it would ensure it stays true.

      Rudy last minutes advice to Bob :-)

    2. Hi Bob. My beam is 31" long. I lose 3/4" at the end past the cutter and at least an inch off the back end to wedge it for the maximum length. So I could probably mark about 29" with it.

      BTW, did you find tools while shopping for chocolate or did you find chocolate while shopping for tools? Hmmm ...

  4. Interesting, mine is smaller, beam length is 19 in. How did you arrived at that number, based on an example or your own choosing?

    I would guess mine would be mostly for panels sides inside M&T frame, type thing?


    1. Bob, nothing scientific in arriving at the stem length. At some point I'd like to make a blanket chest (or something similar) with wide panels. I don't know if I'll ever need a measurement more than about 24", but it doesn't hurt anything to have that extra length. Ralph says his is 36" long. I wonder what he's got in mind for that?

  5. oh yeah forget to add... Says Bob with a face full of chocolates.
    About your last question, it is one of those rhetoric eternal question like what came first the tool or the chocolate?
    or Who's on first, What's on second :-)

    Bob, choking on chocolates, where is my beer :-)

  6. Hi. I admire your work, the panel gauge and the mini chest. workmanship spot on. I now only use a hard pencil in my panel gauge and plane to line, sometimes a ballpoint pen. I notice with your panel gauge has 2 bevels coming to a point, just like a pin marking gauge. I would try for a single bevel more like a knife. No need to harden your cutter, I have found that a hacksaw blade can be shaped to suit

    1. Hi Frank. Thanks. I made the cutter with two bevels so that I could either pull it or push it. The teachers I've seen using panel gauges typically push them, but I always find myself pulling. Just seems to work better for me. The two bevels on the cutter are to have that flexibility.

  7. Nice panel gauge, Matt. Now I have to make one!