Hand Scraping a Hand Plane Sole Flat

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The plane was made by a fellow named Spiers of Ayr, Scotland about a century ago and is of a style called an “infill” plane because of the Brazillian rosewood that fills the body. Its interesting to note that the body was not cast as one piece, but was joined together from three pieces that were double dovetailed together. The joints are so tight that they are all but invisible, a very beautiful feature. And consider that this plane was made by hand!

I started by refinishing the wooden bits, sanding out some of the more minor dings and dents, and then finishing with dutch oil and several coats of paste wax. It looked a lot nicer, but without a blade I couldn’t try it out. To top it off, the wood had noticeably shrunk (a common problem when wood goes from balmy Scotland to Colorado) and probably warped the sole of the plane. I bought the largest blade I could find, a massive 3/16″ thick Lie Nielsen which turned out to be too thick for the mouth of the plane.

The sole presented the greatest problem. I bought a large precision straight edge and a feeler guage set to be able to measure how far out the sole was, and it turned out to be bowed and twisted to the tune of about .006″. I’ve lapped out smaller planes with sandpaper on a granite flat, but this plane was too large, and too out of flat. I considered sending it to a machine shop for surface grinding, but the clamping force on the plane during the grinding process would have warped it, and was too expensive to boot. Besides, sending a valuable antique to a machine shop is just asking for trouble. I finally came upon hand scraping, laid out the cash for a granite surface plate large enough for this monster of a plane, and picked up a nice carbide scraper from Anderson Bros. and the diamond abrasives to sharpen it. I scraped every surface on my drill press and vice to get a feel for the process. It turns out that scraping cast iron is a joy compared to the mild steel of the jointer plane. Scraping the sole turned out to be twice as slow as cast iron for me to achieve the quality of surface finish the plane deserves. You can see in the photos the progression of the sole of the plane as it gets progressively more flat.

The granite plate is inked with prussian blue oil paint and the object to be flattened is rubbed against it. A brayer would have been nice to spread the ink, but my palm worked just as well, as long as you don’t mind a blue hand.

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When you pull them apart, the blue transfers to the metal, and you then take a pass over the inked spots with the scraper. After each pass with the scraper the sole of the plane was deburred with a fine synthetic sharpening stone.

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The scraper removes about .0001″ at a pass. Then you do it again, and again, and many more times, alternating the direction of your scraping pass perpendicular to the last. I’ve since learned that a HSS scraper blade would leave a better quality surface when scraping mild steel. The carbide was prone to galling on the cutting edge, leaving deep scratches that took many passes to remove. I also was truly careful not to slip off the edges of the mouth opening and gouge out a bunch of metal that can’t be put back.

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I probably spent about twenty-five hours scraping, and man does that paint get absolutely everywhere! The resulting pattern of scrapes is quite beautiful with the light reflecting on it, and the quality of the surface is comparable to a high quality surface grind job (the plate is flat to .0001″).

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I knew I was doing a good job when I started to have a hard time getting the plane unstuck from the plate, and having the plate lift on me, which weighs 150lb.  As you approach full flatness of the plane the amount of ink on the surface plate should be lightened considerably.

With the sole flat I removed a little metal around the mouth so that the blade would fit, and polished up the bronze lever cap. Although planes of this period did have blade adjusting mechanisms, this plane showed no screw holes where it would have been mounted. The blade would have also had a cap iron, but the blade I bought was so massive it was not necessary, and I substituted a small piece of oak under the lever cap to make the blade seat properly. To adjust the cutting depth and alignment you tap on the blade with a small hammer.

I’ve received a great deal of satisfaction from restoring this tool. It is the bedrock of accuracy in my shop. It performs beautifully, truly the best hand plane I have. Its interesting to note that I spent about the same amount of money restoring it as it would have cost to buy a brand new top of the line Lie Nielsen, but the Spiers is unquestionably the finer tool.

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