Thread: problem lapping chisel backs

Richie
You only need to lap a 1/4" to about a 1/2"
Should take about 15 mins
paul

I agree the Ingersoll. Don't need to flattern all. Though, personally, I'd want a little more than 1/2"

Its a tough job. Early on, I had a lot of problems too. Really, IMO, don't want to stuff around. You need an abrasive thats going to eat away that steel fast. Or else you'll be there all bloody day.

What I found finally works is to buy a very coarse felt backed abrasive. Its belt like. Can get from Carpatec, Called 'Hermes' paper. Adhere it to some glass with spray adhesive.

And when you lap go in one direction only. So, at the end of every pass,I have a picture here somewhere that shows you what I mean. Found this coarse Hermes stuff to work very well, and quickly. Its from a thread idea I started called 'flat out man' , where I was showing off a flatterning table idea. Might be interested.

Heres that thread
http://www.woodworkforums.ubeaut.com...light=flat+man

Richie,

As you know, I did mine with the cheapo diamond stones (have been back to the market a few times now but no sign of any more of them).

I concentrated on an area about an inch or so long from the tip. Once you grind it away so that the shiny edges are gone, you can then get to work with a waterstone, or scary sharp or whatever.

Maybe you could try a beltsander.

A while ago I obtained a set of Stubai chisels, (better than Two Cherries according to a test in one of the wood mags) and had to flatten the backs.
After mucking about for a day I found the best way was to stick wet and dry paper to a FLAT surface and start out with 80 grit, working your way to finer grades untill you can go to waterstones.

I now use the back of my widest chisel as a mirror while I shave with my second widest.

Originally Posted by Termite

I now use the back of my widest chisel as a mirror while I shave with my second widest.

I hope your not gloating. :eek:

I woder about the issue with making your "hump" worse. Remember, as you flatten, the surface area of the chisel on which you are working will increase. I wonder if that is what you are seeing. Is it that the new shiny area is growing? If so this means you are winning not losing.

As others have said, start out course and work your way up, no good busting your hump.

Thanks for the replies so far.

I forgot to ask - if there was no hump in the back beforehand, any idea how I've managed to create one (the surfaces were flat)? I wouldn't want to do it to another.

Outback,
There is definately a hump in the back. The area increasing as I look at it is the daylight between my ruler and the chisel back


The wet dry I have been trying is 60 grit (on a flat surface)

Richie,
It sounds like you're starting a bit coarse with the wet & dry, but whatever you do, you want to have the abrasive stuck down so it doesn't move or curl up as you pass, thereby undoing the good work. Concentrate on keeping the back consistently flat down, no rocking!
It definitely is a progressive and patient task, just keep eyeballing that growing shiney patch untill it meets the sharp edge. When that happens you'll need to be on the finest stuff (or waterstone) otherwise the abrasive scratches will tranlate into nicks on the final honed edge.
Well worth the effort, but if you're nervous about trying agin, use a cheapy chisel to practice on.
Cheers,