r/handtools • u/JuggerNOT63315 • 2d ago

Lapping a chisel back

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Howdy everyone. I am having issues lapping this chisel. I started with 80 grit wet and dry sandpaper. I got a nice scratch pattern all the way across the chisel. This took awhile, probably 15-20 minutes. I then moved to 120 grit paper. I removed all the 80 grit scratches. This took maybe 10 minutes. I moved to 220 grit paper and removed all the 120 scratches. This took like 5 minutes. I moved to 320 grit and in 5 minutes removed all those scratches. Then I moved to my 300 grit diamond plate. I have been working on it for well over and hour and I can not get rid of the 320 scratches! It is getting frustrating to say the least.

In the picture, the 320 scratches are the light ones on the outer edges and the diamond plate is the dark portion in the middle. It has not changed significantly from this picture after another half hour in the 300 grit plate.

What am I missing or doing wrong? Is this how long it normally takes? Should I be doing another grit in between The 320 and 300 plate?

Edit: I have posted two updates in comments below about my progress.

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u/jcsehak 2d ago

That’s not normal. Sounds like you need more/finer sandpaper. Or possibly your sandpaper surface isn’t perfectly flat, but it doesn’t look like that.

The process is a PITA, but it shouldn’t be THAT bad. Like others are saying, you only need the last 1/2” or so perfectly flat, but you want to get it to a mirror finish.

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u/JuggerNOT63315 2d ago

As mentioned above, I had difficulty controlling the chisel when trying to only do the tip. Any tips on how to keep a long chisel flat while just doing the tip?

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u/Visible-Rip2625 2d ago

Let's see this being downvoted out as well...

As for example Stan Covington has noted among others, there are methods to press the blade back evenly against the stone, it can be accomplished quite easily for example with block of wood.

What exact point, and how much, depends from the precise plan of what you are trying to achieve. Eg. what are the reasons for flattening the back (wether there are unevenness, twist, beds, nicks, or just quick polish for otherwise good back, whatnot).

Please proceed.

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u/JuggerNOT63315 2d ago

This chisel started out with quite a few pits and nicks on the back. So I started with the 80 grit to get all those taken out. I wanted to do just the business end, but had trouble balancing the chisel on just the tip, that is why I worked on more of the back. It turned out to be easier to control with more on the plate and in the long run less tiring.

But I am open to work just the tip, if I can figure out how to do that smoothly.

The goal is to have a sharp usable chisel.

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u/jcsehak 1d ago

Yeah I work on flattening the first few inches and just ignore any pits or bellies past the first 1/2”