Flattening the backs of chisels

Materials

Jonathan Peck -N.Y.

>Firstly, I'd like to mention the materials that can be used for flattening. This list can be deemed incomplete right off the bat

1) Water or oil stones

2) Sandpaper (your choice of type)

3) Diamond plate

4) Drywall screens

5) Lapping compound

Flattening Surface

1) 1/2" glass

2) Granite

I use water stones. I have the Nortons (220, 1,000, 4,000, and 8,000 grit) and the Shaptons (1,000, 5,000 and 8,000 grit. I plan to get the 120 grit also) and find that the Shaptons wear slower and cut faster if properly maintained. This means lapping the glaze off every 10-20 sharpenings. With the lower grit stones (220 and 1,000 grit) I take greater care to use the entire stone as they wear fast. This involves maneuvering the tool and frequently turning the stone. I will also work the tool from the right side with the tool in my left hand and the right hand guiding and adding pressure and also switching to the left side. I flatten my stones with an x-coarse 220 grit 30 micron Norton diamond plate. With the 4,000, 5,000 and 8,000 grit stones I finish on wet/dry sandpaper and go up to 320 grit.

diamond plate - I have x-coarse, coarse and fine

drywall screens - I like the open mesh which does not clog and the fast cutting action. It works great for oldtools with some rust.

wet/dry sandpaper - I use 220 and 320 grit but also keep a few sheets of 600 handy. I lubricate with turps. I aslo keep low grits of Al Zirc on hand.

1/2" glass surface (personal preference) I got glass shelf from a demo job

Here's a pic of my sharpening area

Where to start

Jonathan Peck -N.Y.

>For a new tool, the first step is removing the protective lacquer coating. A little lacquer thinner with fine steel wool followed by a soft rag should do the trick.

I've never tried the new LN chisels, but based on what I've read here they are ground pretty flat to begin with (much like their plane blades and soles). It's important to note that the lower you go in grit, the longer it takes to get to polish, as each step involves removing the marks left by the previous grit. If you are starting with say the LN chisel which is already ground pretty flat, you could probably start at 1,000 grit as all you may need to do is take down any mill marks. I would say that part of the difference in price between a $10 and $50 chisel is in the time the maker spends in finishing the tool, or put another way - fit and finish - ie. time is money. That said, it is not a stretch to say that the LN chisel will be easier to put into service than the LV , Two Cherry, or the Marples Blue Chip. Another part can be attributed to the materials used - ie. handles, tool steel etc... A third factor would be the tool design/construction. This area I don't have much knowlege on, but I am aware of the differences in tangs, how they join with the tool handle, ferrules, shock washers etc....I believe that all these makers use A2 toolsteel hardened to somewhere between Rc 60-62, so given any minor differences in steel composition, they should all perform similarly when properly tuned and sharpened.

For an old tool, you may want to start on drywall screen to remove any rust or crud before moving to a diamond plate, sandpaper or a water stone. I have different grits of everything on hand, including drywall screen. After I have cleaned the tool, I usually start on a higher grit such as 1,000 taking a few passes to get a read on what I need to do to flatten the back. This should expose any problems and low spots the tool has.

From this point, I will try different things using judgement or a few test passes to see which is the highest grit that will allow me to do the job the fastest.

(dissclaimer - I am not an authority on this topic, nor do I play one on TV. I am open to all opinions, constructive critisisms and corrections as I would hate to provide missinformation and let it go unchecked)

Thanks

A2 in Marples bluechip???

Jonathan Ronnow, Sweden

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chisel steel

Bill Tindall, E. TN

>I asked one of the steel suppliers what was typically used for chisels and I was told

S(something) maybe S7. I didn't think to write it down at the time. The S steels are very tough and this would be important to lessen the tendency of snapping the edge off in use. A2 is a tool steel and one would only expect it to be used in a premium chisel. I do not know how it would do as a chisel as I have not tested A2.

Very fast Flattening

Bill Tindall, E. TN

>No flattening task is more difficult than the CPM 3V tools we made and foolishly didn't flatten before hardening. A Makita horizontal wheel ground the backs of chisels and plane irons in just a few minutes or less depending on the roughness. It is safe to say that a normal steel chisel would become flat in a minute. We did a horribly unflat carbon steel draw knife in 5 min or so. Once flat with the power equipment, it is but a minute or two to take the tool through the various grits to a polish.

I can't keep a back dead flat with sand paper. The leading edge(the edge I am pushing toward) always over-abrades. We now use cast iron plates charged with diamond powder.

Chisel tool steel

Jonathan Peck -N.Y.

>I for one would love to hear more regarding the charecteristics/selection of toolsteel used in making chisels. The makers viewpoint of challenges involved in choosing steel composition characteristics from a fabrication/finishing/price/edge retention and abilty to sharpen is a topic few us us are challenged with.

According to Lie Nielsen...

Bryan Danner - Broad Ripple, IN

>I'm not claiming to be an expert here, but it's my understanding that Lie Nielsen is the only commercial producer of chisels made of A2. I checked their website for info, and here is a quote I found:

"...I know of no other examples of commercially available A-2 chisels, partly because A-2 is hard,

difficult to forge."

I realize that trusting web-site info is dicey sometimes, but Lie Niesen tends to be pretty reliable in what they say. Even if there are others, I think it's safe to say that A2 is not common in chisels.

see new post above for a start

Bill Tindall, E. TN

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