Tuesday, March 21, 2017

Fixing and Fettling a Wooden Plow / Plough Plane - Part 1

Well, the trip to Death Valley was great, though it was HOT!!  Mid to high 90's most days, about 15° warmer than usual for this time of year.
Notice the temperature at bottom of this gauge in the rental car
On this trip, we also visited Valley of Fire (about an hour east of Vegas), Ash Meadows (just outside Death Valley NP on the south east side) and Red Rocks Canyon (just west of Las Vegas).  All were fantastic.
View of the Badwater area of Death Valley from Dante's View
Badwater is 282 feet below sea level.  Check out the sign about 3/4 the way up the mountain in the following picture.
The arrow points to the sign that reads "SEA LEVEL"

Enough of that, time to get back to woodworking stuff.

A couple years ago I bought an Ohio Tool #96 wooden screw arm plow plane off Craigslist for $45.
At one time owned by H. L. Allen
The plane was in rough condition.  I worked on it at the time and thought I had it in useful condition.  A really great article by Zach Dillinger guided me through some of this, though I did not heed all his advise.
Right side
Left side
Since then it has been on a shelf, mainly because it came with only a single 1/2" iron and I have never needed to plow a 1/2" groove.  I recently picked up a few more irons in sizes that are more useful for the work I do and that gave me the impetus to look into this plane again.

This post will show what I did to fix the plane a couple years ago.  Warning - some parts of this post are not for the squeamish.  Succeeding posts will show the further work I need to do to get it working properly (hopefully).

First is the fence assembly.  The screw arms are attached to the fence with screws from below.
The fence and screw arm assembly
Screws go through bottom of fence and into the screw arm posts
One of the screw arms was broken from its post.
Broken post at bottom of pic
Close-up picture
Fortunately this was a fairly clean break and I was able to glue it.  Polyurethane glue was used - this glue expands and fills gaps as it cures.
The parts clamped up with the glue expanding in the joint
The previous owner had ignored this and let the screw that holds the screw arm post to the fence hold it together.  In fact, he used an extra long screw that went all the way to the top of the screw arm, making a small hole in the top of the post.
Arrow points to hole in top of screw arm post
I shortened the screw a little by cutting it down a few threads and filing a taper on the end.

The second and much larger problem I'm sure most readers noticed already.  On both wooden screws, several threads were damaged or missing where the screw begins from the post.  (See pics of the broken screw arm above.)  I didn't notice this when I bought the plane because the wooden nuts were covering that area and I was not diligent enough to check.  This got me into a long sidebar of trying to make wooden screws to replace this - not a very successful set of experiments.
Front screw
Rear screw
This is the area of threads that really needs to be in decent condition for the grooves that I might do.  For grooves that are 1/4" to 1/2" from the edge of a board, the nut in the above pics would be right in that area.

Some options were
  • Make a big fat auxilliary fence that attaches to face of existing fence, bypassing the damaged and missing threads - didn't seem optimal
  • Rebuild the threads on the existing screws - no idea how this might be done
  • Make new screw arm assemblies - that's the screw-making rabbit hole I mentioned above
  • Ditch the screw arms and make a wedge arm - didn't really want to do this
  • Cut out the damaged thread area and dowel the screw arm back together
Well, the last option was the winner and it came out remarkably well.  I cut out about 1 3/8" of damaged area from each screw.
Cut out the damaged section and drilled holes for a dowel in mating parts
I did my best to drill the holes in the right location and straight.  In retrospect, I can think of ways to do this more accurately, but it came out pretty good.
Dowel in place, later glued and clamped
They're 1 3/8" shorter, but no one will ever know
Another problem had to do with the depth adjuster lock mechanism.  The lock mechanism is a thumb screw that threads directly into the wooden plane body and the threads were mostly dust.
Depth adjustment assembly
Mortise for the top part of the adjuster - locking thumb screw seen at bottom of  photo
The stripped hole for the locking screw
I drilled the hole out, glued in some wood plugs, re-drilled an appropriately sized hole, and used the thumb screw to thread its way into the hole.
It's not pretty, but works perfectly
Thumb screw in place
There are some other problems with this plane that I'll address in a future post.


  1. Matt look at this for ideas on fixing the threads

    1. Wow, wish I had seen that a couple years ago. He went to a lot more trouble than I did. But he got a better result, too. Great stuff.

  2. Good recovery on the damaged threads. Not sure if i would have used poly glue, yes it expand and gap fill but the actual expansion of the glue is more like insulating spray foam than a hard glue line. My glue of choice would had been epoxy, and thart would probably be a tad overkill... but that is just me, overkill everything :-)

    Bob, nurturing a man cold. The hazard of having your girldfriend driving a school bus i suppose...

    1. Hi Bob. The metal screw that holds the screw arm post to the fence will also help hold the broken post together. Thanks for the tip on the epoxy. Gotta remember that for next time. Hope your cold passes quickly.

  3. You know, the more i look at these pics, the more I am wondering if that side screw to "lock" the depth adjuster is original. As you seen by the damages it caused, it sure seems to be a dumb idea, and why is that screw metal instead of brass like the others?
    I own 4 of these beast and none ever had that side provision to lock the depth setting, relying on the adjuster back lash to keep it there.
    Cannot help to wonder if that is original or a later user mod...
    In any case, i would not rely on it.
    Great restoration you got going there, good job

    Bob, still probably delirious :-)

    1. Bob, I had the same thought about the depth adjuster lock thumb-screw. I thought it should be brass. Maybe it's not original equipment. I thought I had seen it on another #96 plow plane when I did an image search, but I can't seem to find it on a search I just did now. Either way, it does work even when you don't crank down on it too hard, so I don't think it will hurt anything if I use it.