Monday, July 25, 2016

Workbench Top Re-Flattening and Making a Scratch Stock

I've been aware for a while that my benchtop has gone a little out of flat.  I built the bench last fall from kiln dried Douglas fir so I thought it wouldn't move much.  Over time the top has shrunk a bit and twisted a little.  I don't need the top to be perfectly flat, just reasonably flat so I can test boards for twist by laying them on a flat surface.
Above bench, looking down: right front leg proud of top by 2-3 mm
When I assembled the bench, the front face of the front legs was flush with the edge of the top.  As Chief Inspector Clouseau said to the lady whose priceless Steinway piano he just ruined, "Not anymore".
High spots at back left, front right and center along slotted strip show up lighter after a couple passes
I'm fortunate to have a Lie-Nielsen #8 jointer.  This beast is 24" long and works fantastically well.  I took a few strokes diagonally across the bench and I can see it was removing certain high spots.  I also used the plane on its edge to show where high spots were and removed them with a #4.
Looking for high spots
After taking the surface down to bare wood and tweaking with winding sticks and a little more planing, I was happy.  I've got a brand new surface, reasonably flat.  I can probably do this many more times (if needed) before I risk having the top edge of the metal vises coming too close to the benchtop.

I've been wanting to make a scratch stock for years.  I've used the Sellers "poor man's beading tool" and that worked OK, but I'd like a tool with a bit more versatility.  Bob Easton had a "Google Books" link (somewhere in his blog site) to an October 1999 "American Woodworker" article by Tom Caspar about making and using a scratch stock.  My tool is based on that article.

Started with a piece of 1" thick x 5 3/4" long x 2 1/2" wide maple salvaged from a junked table undercarriage.  Squared it up and marked out the scratch stock.
Marked and ready
Cut carefully to the lines so very little clean-up was needed
Drilled 3/16" holes (and later countersunk) for some 10-24 machine screws
Made the holes 3/8" on the other side and chiseled out the shape for the nuts
Screws and nuts fitted
Then I cut the block in half, cleaned up the sawn surfaces with a #4 and did a little shaping to ease the corners and edges for comfort.  The underside of the arm gets curved a bit so that the tool can be angled slightly in use.
Underside of arm (facing up) curved with rasp and file
For the cutter, I used an old (really crappy) no-name saw that I got from a garage sale a couple years ago.
Cut off a piece of the saw blade
Filed off the teeth and got a flat edge
Rubbed it out on sandpaper to clean up the sides
Used a saw file to start a V groove, then a round 7/32" chainsaw file to cut a half-round profile
Cutter all done
Cutter installed
The cutter was a little wider than I needed and the bolt upper right in the above picture interfered with its placement.  So I filed a little cut-out so that it would straddle the bolt and sit at the right location.  And here's the first test drive.
Test cut in pine scrap
It worked fine, but got hung up a little on the soft and hard growth rings.  I'll have to try a harder wood soon.  But with a tiny bit of sanding, the bead was looking great!  I also tried a stopped cut to do a corner.  This time I used a wheel-type marking gauge to scribe a line before using the scratch stock.  Probably didn't need that with the grain, but definitely needed it cross grain.  This came out OK, but not perfect near the corner.
A little ragged near the corner
I noticed that you have to clean the tool often, and I did this with a knife point.  Tiny dust-like shavings get stuck in the corner as can be seen in this pic.
Mound of dust in the corner just above cutter
And another one from the To-Do list bites the dust.  Hoorah!


  1. I wish I had seen this post before I bought my LN beader.

    1. Haha. Something tells me your LN beader has a bit more capability. Have you used it much? What are your impressions of it?

  2. Well done! A scratch stock is something you'll appreciate many times over. Especially when you consider the cost of beading planes and other beading tools.

    Frequent cleaning is simply a factor of scratching pine. When you try on a hardwood, without the pitch, it'll be a lot easier.

    1. Thanks Bob. And thanks for the link to the Tom Caspar article, too.

  3. Hi Matt,
    great write up and nice beading tool.