Plane Iron Rehab – The Force Multiplier

When restoring a plane iron my starting point is always flattening the back, a frequently arduous task as a surprisingly few irons have undergone such a corrective action.  As a result, the time and energy for this step is an outsized proposition.  Even with coarse stones, diamond plates, or abrasive paper, flattening the back of a derelict iron can be a real workout.  Generally, I’ve found that it is practically impossible to work the iron too hard on the abrasive, whatever it is.  And, although I have pretty big, strong hands, it can be wearying session.  To make it less of a nuisance I need a force multiplier.

This is where The Magic Stick comes in handy.  This fundamental tool was introduced to me by my late, lamented and much-missed work pal Mel Wachowiak (his obituary is still tacked up in my shop), who in turn learned it from somebody working on a Japanese plane iron.  The tool is beyond basic but required for a new Japanese blade as the “grabbable” real estate for handling the blade is roughly half that of a Western blade.

With the Magic stick you can really, really bear down on the blade when working it on the stone or sandpaper or diamond or whatever.

By gluing a piece of very coarse sandpaper on the bottom of the stick with epoxy, and pressing that coarse surface against the upper side of the iron, you are no longer limited by hand strength and endurance for flattening the back.  You can basically impose the downward force of your entire upper body on the workpieces with surprisingly little effort.  This approach cuts my work time for the initial set-up of the back by at least 75% and at times 90%.

Recently I brought up to snuff a narrow coffin plane that had been originally used as a semi-scrub plane, and it had been worked mighty hard if the mushrooming of the iron heel was any indication.

 

 

Looking closely at the iron I saw that the bevel had been established on a bench grinding wheel or something similar.  But the edge had never been honed and the back never flattened.  The iron was essentially straight-from-the-factory forge.  I knew this because the fire scale had never even been touched!  (I’m still kicking myself for not getting better pictures of this.)

Fire scale is the deposit that forms on the surface of metals when they are worked at high temperatures, it is the stuff that sloughs off when a blacksmith is working a piece of wrought iron or steel.  Not being a metallurgist I am not 100% clear on the composition of ferrous fire scale.  All I can tell you that it behaves carbide-ish, hard and tough.  Very hard.  Very tough.

So, on this blade I had a lot of fire scale that needed to be ground off to accomplish the preparation of the vintage iron blade.  Just abrading it on a diamond stone was brutal work by hand, but with the Magic Stick it was doable in about 10 minutes.  BTW, the carbide-ish ferrous fire scale was so tough that it trashed my 120 grit diamond stone.  Absolutely trashed it.  I wound up doing most of the work on a piece of folded silicone carbide paper.

Working my way up through the grits on diamond and water stones, a dozen seconds at a time, was a piece of cake thanks to the Magic Stick.  This blade is not the previous one with extreme camber, but an example of a blade back that was prepped in just a few minutes.