Saturday, April 5, 2014

Establishing a new bit angle on a carpenter's hatchet restoration

After the first visual transformation from removing the layers of corrosion to the initial polishing 
comes the first steps of actually modifying the blade. this is when we start to establish a more optimal cutting edge, the angle from the cutting bit to the tools cheeks.

before i continue on, i would like to step back to the last step and quickly give some words as to why it is important to immediately polish the tool after removing from the vinegar bath.
 that caustic soak has two purposes: to remove corrosion and to test the temper. when the old corrosion is removed then the surface area is increased, therefore the tool can quickly degrade again.
the images of that craftsman after just one week shows the process in action and that was when it was cold and very low humidity!
 in the summer the acceleration would be alarmingly fast. allowing this to happen would be counter productive to our attempts to move this tool forward. the polishing will afford us the time to continue the restoration process without any steps backwards, even if life gets busy and there is alot of time between being able to work on the tool.

with that said, lets put this head in the jig and remove some metal!
this is a chance to do some more forceful work on the tool without the handle getting in the way or even doing damage to the handle while laying down a heavy hand. 
this is the time to: 1= decrease the angle from the bit to the cheeks 2= remove any chips 3= improve on the profile the bit (fix the asymmetrical sharpening from past owners).

now there are a few times when i am lucky enough to acquire a tool that needs no jig work, but in all honesty that is more of a rarity. mostly that happens when someone comes to me with a project to restore a tool already in pretty good shape, minus a chip or two. BUT because i do this out of an obsession, i really like the challenge of bring back to life quality tools that have the potential to be great but are in a current state of disfunction.

below is an old hatchet that has very good quality steel. although the tool was not overly misused it was definitely in need of some jig work.  my goals for this session were to symmetrically decrease the angle from the cutting edge to the sides of the hatchet. this will make it a more efficient cutter.  while doing this i will also be able to give that edge some point too. this tool was so dull it was visually rounded on the bit. this simply could NOT have been safe. a sharp tool is a safe tool and this striker was as dangerous as it gets (probably couldn't even strike warm butter without glancing off).
a detail of the carpenters hatchet getting some symmetrical adjustment to the business end

in the jig, the tool is worked by switching sides over and over again. By the end this jig work the angle was looking symmetrically efficient.  
i would like to stress here that when i am finished on the jig i am by NO means finished with the shaping nor the sharpening. i will still need to create an optimal edge by turning this flatter transition to a more convex style grind with diamond files and sharpening stones.

the last item to mention is that although this tool will make a perfect striker when finished, i do leave enough steel still intact so the new owner can have the chance to do his or her own modification. it is all about what is best for the new owner.

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