Cheapest way to flatten chisels?

[Lasse Hilbrandt]

Im in the market for old chisels that needs restoration. I have found out that most of them are not flat on their backs. So far I have been flattening with my Norton wetstones, but it takes a hell of a time and wears a lot on my stones.

What is the fastest and cheapest way to flatten them ?

[Prashun Patel]

Worksharp with 120 grit Diamond lap plate. One of many ways. There's mine.

[Lasse Hilbrandt]

Worksharp with 120 grit Diamond lap plate. One of many ways. There's mine.

Prashun, Worksharp, is that the machine with the horizontal disc ?

[Patrick Chase]

Worksharp with 120 grit Diamond lap plate. One of many ways. There's mine.

Or the Veritas power sharpener, which is also an 8" disc grinder.

I've always had trouble getting chisels truly flat that way, though. The speed difference between the inside and outside of the wheel leads to grinding-rate differences, and I find that I have to do a fair amount of lapping afterwards to get a truly dead flat back.

Depending on how much your time is worth the cheapest solution overall may be "buy chisels that are already flat".

[Lasse Hilbrandt]

Patrick that defeats the purpose of restoring old chisels ;-) I already have the new Veritas chisels. Restoring I do for fun, but it would be even more fun if I could speed up the proces in the cheapest possible way.

[Phil Mueller]

Cheapest....a piece of plate glass or scrap granite or marble tile with 80 grit sandpaper. May not be the fastest, but keep in mind, only about an 1" really needs to be dead flat. I've flattened many garage sale chisels this way. Work up from 80 grit to 220 and move to the stones.
Actually, I run an old chisel over 220 grit first to see how bad it is. Then, depending on how bad, start with 80 or 100 or 150; the smallest grit to get it flat within a reasonable amount of time.

[Allan Speers]

Im in the market for old chisels that needs restoration. I have found out that most of them are not flat on their backs. So far I have been flattening with my Norton wetstones, but it takes a hell of a time and wears a lot on my stones.

What is the fastest and cheapest way to flatten them ?

"fastest" and cheapest" don't belong in the same sentence.


Cheapest: Get a cement block. (they are flat due to gravity as they cure, just like plate glass.)

Rub your chisels until your fingers get numb, then switch to a finer-grit cement block.



I actually read an article once about an old timer pro woodworker, who actually did this.

[Patrick Chase]

Cheapest....a piece of plate glass or scrap granite or marble tile with 80 grit sandpaper. May not be the fastest, but keep in mind, only about an 1" really needs to be dead flat.

IMO this depends on the chisel. For, say, a paring chisel that gets used to clean out slots and dadoes I prefer to have (a lot) more than an inch. It's OK if it's a little bit concave and the chisel is flexible enough, though even in that case you have to remember to apply enough bending force so that it lies flat and doesn't dig in.

[Ray Selinger]

You should have added easy as well. When I find an old pitted rusty chisel I belt sand the back down as far as the pits. $1 for the chisel, $7 for the 6x48 belt . I've used 120 wet/dry paper to get the slight rounding out. Today the Eskilstunasteel, Berg and two Swedish patterned Footprints didn't require much. I only hone near the edge.

[Phil Mueller]

100% agree. For garage sale stuff, I usually hope for 1"...if lucky, you can get much more. Just not something I count on from a rust find.

[Robert Hazelwood]

The best way I have found is just to use sandpaper stuck to something flat, and make sure to use fresh sheets. I'd start with 80 grit, then 150, then 220, then go on to my 1000 grit waterstone and on from there. I've tried to find a better way, buying coarse diamond stones and waterstones, but I've found coarse sandpaper just works faster. And it's cheaper unless you are constantly restoring chisels.

If there is a lot of damage/pitting at the edge, I won't hesitate to grind back the edge (grind at 90 degrees) to get rid of defects. I've also put a few bad blade backs on a belt sander to get rid of the majority of problems, but that is risky.

[Jim Koepke]

Not much to add. I use the Veritas Mk.II Power Sharpening System, similar to the Worksharp, and have been able to do fine with the rotational differentiation. I also have a 4' long piece of granite from a monument maker (tombstone carver) with abrasive paper attached. I do not do as much flattening as I used to, but as far as I am concerned I have done a lot better spending a little time restoring the old than spending a lot of money on the new. Besides the enjoyment it brings, no one has offered to pay me money to not do it.

jtk

[Don Jarvie]

Norton has an combo oil stone, course and fine, that will make quick work of it.

You need the back flat if you want a good edge so it's worth the time.

[jamie shard]

For sure, the best and fastest way is cheap sandpaper on a flat surface, then move up through the grits you already have for sharpening.

[Phillip Mitchell]

It's not the cheapest but not too bad at around $65; I lap my newly-acquired old chisels with a DMT XX coarse diamond stone. I think they say it's 120 grit. It's not too bad on chisels under 1". I have been restoring a handful of timber framing chisels (1 1/2 - 2") and it takes some elbow grease, but a lot quicker and more effective than waterstones. After it's lapped flat, I use a Tormek to either grind a new bevel or spruce up the current bevel if it's appropriate, then I go to the waterstones. I'm fortunate to have a Tormek that sits in the shop at work that I can use anytime I want.