Above all else, to me, this stage is the most important part of reviving an old hand plane. A flat and polished sole makes it run like new again and perform significantly better. Based on my experience, I would bet that the manufacturing tolerances on old Stanley planes were not too strict, as many of the planes i’ve restored were way out of flat, even if they didn’t seem to be heavily used.
A flat polished sole will allow the plane to glide smoothly, will decrease tear-out and greatly improves the look of the plane.
To start off, i use a 12”x12” x3/8” piece of plate glass. Spray on a light mist of adhesive and lay on a sheet of 60 grit paper. Depending on how bad your plane is, you may not need to go as coarse.
I push the plane providing even pressure on the knob and tote at a 45 degree angle to maximize surface area on the paper. Occasionally I will swich hands and push it the other direction. I will usually do about 150-200 passes over the paper at first to remove any left over rust and tarnish to see what I have to work with.
Use your shop vac every 50 or so passes to remove build up on the paper. It accumulates and clogs the paper quite fast but will suck up easily.
In the above picture you can see the diagonal scratches created by the sand paper, and the horizontal scratches that were pre-existing that I am working to remove (Especially near the mouth)
Once I have removed most of the scratches and gouges and have a somewhat even sanding pattern on the sole, I take a square and a marker and mark out lines on the about an inch apart, and one on either side of the mouth:
I then continue making passes over the paper, checking the sole every 20 or so passes to see how the marker is wearing off. As you can see, It is wearing off slower on the back of the plane at the top of the picture. That shows that that is a low spot. I will need to keep going until that is all rubbed off, then repeat the process:
I find that I often have to repeat the mark-up 2-3 times until alll of the lines fade evenly. Once the lines are fading evenly and you have eliminated all of the deep scratches in the sole, you are likely close to flat. Check the sole both length and width with precision straight edge if you have one (Or use the back side of your glass plate if you don’t).
Once you have flattened the sole, you can go ahead and do the sides in the same manner. When doing the sides, be sure to have even pressure and check frequently with a good engineer’s square to make sure that you are squaring up the side, not making it worse!!
By the time you are done with the 60 grit, your sole and sides should be flat, free of deep scratches and gouges and ready for polishing:
Peel off the paper (you may need to use some solvent to get it up) and scrape off your glass with a razor blade being careful to remove any lumps/bumps while avoiding scratching the glass.
The next part of the process (to follow in the next post) involves polishing out the scratches created by the sand paper, working towards a mirror finish that will look better than most planes do out of the box