Notes on Restoring a Plane.

Post date: 01-May-2018 23:23:33

Figure 1. The Plane as Found. Plenty of Surface Rust and Minor Damage to The Wood.

Among tools being auctioned by the club from the estate of former HTPSWA chairman and founding member, the late Bob Shoosmith, was a derelict rusty Spiers infill plane.

It would have attracted a lot of interest except for some major damage to its rear, where a long past former owner had cut away a section of wood in a most unprofessional and unattractive manner.

Figure 2. Major Damage at Rear of plane

I could, and perhaps should have avoided it, but I am a sucker for a challenge, so I bid for it with little opposition and won.

It was not at all clear to me how to deal with the plane. This is indeed a challenging restoration job.

To Restore or Not?

I don’t want to imply that restoration is always the best thing to do. Hand tool enthusiasts hold a wide range of views; from people who happily repaint black japanning, or polish with Brasso, to people who oppose ANY changes being made. Then there are pure collectors, and people who decry perfectly good tools being put on a shelf, and not used as originally intended. We as members need to respect such views, some of which can be held with a great deal of passion.

If you are thinking about restoring a tool, you would do well to be aware that there will not be universal agreement that it is the correct thing to do. The decision to restore is not one to take lightly.

I far prefer not to restore or repair tools, but I see little choice in this case. The plane would likely end up in a skip if no-one recovers it, so I am not compromising a valuable bit of heritage.

 Exploratory Surgery

At this stage the main task was to explore the situation as fully as necessary to reach an informed decision on the best way forward.

Before we go further, a note about how these planes were originally built is appropriate.

If you have ever considered making your own infill smoothing plane you will have come up against the difficulty of shaping and fitting the rear infill. It is an odd-shaped part with very few reference surfaces to measure from.

The commercial makers, Spiers, Mathieson, Preston and probably Norris all made this job easier by building the rear infill of their smoothing planes in two pieces (see Fig 3):

- A lower section with its top surface flush with the tops of the metal sides of the plane, and

- A top section glued to it that extends over the metal sides to be flush with the outer plane surfaces. If you look closely at any of these planes you will see the join by sighting down the blade bed, or at the rear, where you might see an abrupt change in grain pattern instead.

Figure 3. The Rear Infill is Made of Two Pieces of Rosewood Glued Together.

Close inspection revealed the top part of the infill to be slightly misaligned, in a way that would have prevented the plane working properly. With this being the case, it was necessary to separate the two parts of the rear infill. This was achieved by tapping a carefully-placed chisel, to reveal the original joint surface with its toothing marks and animal glue bond.

I learned something new about the original construction after doing this. The top infill has thin rosewood fillets glued to its sides. This is how the outer wood surfaces were made flush with the metal sides of the plane. The fillets are cut from the same bit of rosewood as the central bit. They are fitted so neatly that the joins are not detectable on the dressed outer faces.

Figure 4. Detail Showing Side Fillets Glued to The Main Part of The Rear Infill.

Having explored the situation in sufficient depth it was time to set the job aside and carefully think about the next step.

Cleaning the metal sides.

With the plane disassembled as far as it is going to be (see Part 1), this is the best time to tackle the metal parts of the plane.

The orange live rust was wire-brushed away to reveal shallow rust pits surrounded by unattractive dark blotches amid patches of clean metal. This is not great news because anything done to remedy the situation will irreversibly alter the surface.

Avoid this step if you can, but I draw-filed the sides until most rust pits disappeared, then used abrasive cloth down to 400 grit, to reduce the inevitable scratch marks. I used various holding methods to keep the scratches parallel to the sole and cleaned the file frequently with a file card to reduce the risk of pinned bits of steel cutting deep scratches. The steel ends up brighter than I am happy with and has coarser tooling marks than were originally present, but my experience is that these settle down over time.

I treated the sole similarly but left more rust pits than on the sides for fear of widening the mouth by taking too much metal off the sole.

This might be controversial, but I find draw-filing to be the most accurate way to flatten a plane’s sole to the standard needed for high performance planes. Sanding as suggested by the books may be simpler but is prone to rounding the sole in my experience. Although draw-filing leaves deep scratches on the sole, careful finer abrasion

can make smooth flat areas between the scratches, achieving a suitably flat and smooth surface overall.

Cleaning the Blade Assembly.

The parallel blade (or iron) is made by fellow Scottish maker; Mathieson and has an early serrated-border brand mark consistent with the early age of the plane itself. It is a composite of soft iron forge-welded to a tool-steel cutting edge. The soft iron part of the blade has a rough stippled surface with areas of dark oxide scale. These must be original features acquired from the blacksmith’s forge. In view of this I did little more than to wire brush the orange rust away. I doubt these early blades were ever bright metal, except at the cutting edge.

Cleaning the Gunmetal Lever.

My observations of well-preserved gunmetal screw-levers suggest their front faces were originally dressed sufficient to remove all tooling marks, before being coated by French-polish. Often the metal and polish have mellowed to give an attractive warm gold colour. This cannot be replicated successfully as you cannot abrade away all the little dents and scratches with their oxidised bottoms that the tool has acquired over its life. Polishing them as is would look like an amateur job.

The screw-lever had a few speckles of original polish surrounded by unattractive oxide patches in some parts and abraded scratched metal in other parts. I went for the minimum cleaning needed to make a more even surface. I used a worn bit of Scotch Pad with a salt and vinegar mixture which works well on brass and gunmetal and does not leave an unduly bright polished surface. One note of caution; salt and vinegar will be highly corrosive on the adjacent steel parts, so neutralise it with baking soda and wash & dry the area thoroughly. A final burnish with 0000 grade steel wool softened the finish.

Figure 5. Cleaned Gunmetal Lever and Blade

Repairing the Rear infill.

The top part of the rear infill was the most difficult part of the job, as it had a missing chunk sawn off by a previous owner. I cleaned the sawn rear face and planed it flat. Then I replaced the missing chunk of wood in four steps. First was a rosewood core fixed to the original piece with a sliding dovetail joint (see Fig 6). It extends to the back of the plane but does not extend to the top or sides. I then carefully fitted chamfered fillets to the top and sides of that core (Fig 7). The chamfered joins are much tighter than the end-to-end-grain joint in

the core piece.

Figure 6. Sliding Dovetail Core.                                                                          Figure 7. Chamfered Fillets Attached to Rosewood Core.

As the top and bottom halves of the infill were originally held together with animal glue, I used similar glue to reattach them.

This unhandled plane model presents a simple shaping job. There are enough photographs of similar planes on dealer websites to give a clear picture of the correct shape to copy. The vertical rear face of the plane is simply curved to the same profile as the curved heel of the steel sole. The radiused top edges are then continued around the back of the plane. These were achieved by sawing, rasping and sanding to shape.

You Can’t Get Rosewood Any More.

Prior to the Second World War the commercial plane makers, Spiers, Mathieson, Preston and Norris, mostly used Brazilian Rosewood for their planes, as did most tool manufacturers in general.

Since then, Brazilian Rosewood has become an endangered species, and was protected by the UN Convention on International Trade in Endangered Species (CITES) in 1992. Most countries prohibit export or import of rosewood blanks and manufactured items because of this protected status.

I used Indian Rosewood for this repair, having bought a few pieces from a Sydney specialty wood supplier many years ago. I don’t have enough left to do many more repairs like this.

Indian Rosewood and all other rosewood species were afforded CITES protection in 2017.

You will not be able to get rosewood for repairs like this in future.

 Finishing.

I avoid refinishing if possible.

My preferred approach is to clean wood parts with one of the many cleaning mixtures available. I have used this one for many years: 3-parts turpentine, 3-parts raw linseed oil, 3-parts vinegar, and 1-part methylated spirits. I got this recipe from an article in HTPAA's Toolchest journal. There are similar recipes published in various furniture restoration books. Rub this mixture on and off with rags. Then remove stubborn spots of house paint etc. with finger nails and harder implements as needed.

Even if the resulting surface doesn’t look to have any preserved French-polish, it is worth trying this next step. It is an old French-polishers’ method for rejuvenating polished surfaces. It was first described to me by Ray Bellinger who used to give French-polishing talks at the Perth Wood Shows.

Thoroughly mix 2-parts raw linseed oil with 1-part methylated spirits. You only need a few drops of this mixture for a typical hand tool but be absolutely certain to have more oil than metho. Rub this on the wood with your fingers until the surface feels very slightly tacky. Then rub off with a clean cloth. This can brighten polish you didn't think was there. Any polish you could see beforehand, will look brilliant after this

treatment. The method does not add any new polish and does no harm to the patina of scratches and dents on old tools. I have found this to work wonders on japanned metal surfaces also.

For the present project, the repairs necessarily left bare wood, so the above methods are not applicable.

Up until about the 1930’s commercially made infill planes were French-polished. Later Norris planes are finished with some sort of varnish, similar to our modern polyurethane finishes.

The trouble with refinishing is that unless you sand so deep that you risk compromising the shape of the work piece, you still have dents, scratches etc that form part of the aged patina. Shellac or varnish sink into these depressions. Each little indentation ends up with shiny edges that are the hallmarks of an amateur refinishing job.

I solve this by filling the dents with hard stopping-wax before applying the first coats of shellac. This is a conventional French polishing technique. Once the French-polish is fully cured, you can either leave the filled dents, or pick the wax out of them with a none-too-sharp awl. This leaves the dents and scratches unpolished, more in keeping with their original state.

With only a few bits of rosewood to choose from, I could not get a really good colour match between new and old wood. Application of wood stain prior to polishing partly corrected this, and addition of spirit-based stain during the skinning stage of the French-polishing process further reduced the visual impact of the new pieces.

The repaired surfaces look too new for my liking and lack any patina. This was always going to be the case, however I prefer to leave them like this rather than attempt to forge an artificial patina.

The End of the Journey.

After tuning up the blade assembly, properly mating the cap iron to the blade and bedding it solidly on the blade bed, the plane now works superbly.

Figure 8. The Completed Plane Cutting Fine Shavings

This project has transformed the plane from an ugly duckling that attracted little interest, and did not work properly, to a presentable, fully operational item. The repair joints are very tight but are still visible to anyone who looks closely, and the market devalues repaired items. Nonetheless this work must have added value to the plane somehow. I am under no illusions that the days I spent on it can ever be reflected in the value of the plane, but that was never my purpose.

This has been about skill, historical knowledge, learning, and their preservation, values that go way beyond the object itself.

Or I could have avoided buying the plane in the first place….

Thanks to Vic for this interesting article.