Any update on those CPM 3V Chisels

some updated information

Bill Tindall, E. TN

>I know that several people have made chisels and an extensive plane iron evaluation is underway(not by me)by people experienced with making and using plane irons. I don't have information that would enable me to comment on these experiences.

I have a lot of use now on a variety of chisel types and the edge is certainly durable. I don't have many comparisons beyond what was originally reported except one "blue steel" Japanese chisel from Japan Woodworker comparison. Under one set of conditions (pareing end grain)the blue steel suffered micro chipping at the edge while the 3V did not. Cutting across end grain seems to be a particularly severe test of edge survival.

We have been very pleased with lathe tool performance. Edge holds up well, and in scrapers where a burr is used the 3V makes a particularly robust burr.

We have found that diamond paste or powder charged on some flat substrate provides cheap and rapid sharpening of this and other tool steels. I initially dismissed diamond as too expensive for mortals to use, inspite of the fact that all the abrasive manufacturers suggested it for steels of Rockwell 60 and higher. Turns out it is very cheap. It takes but a few cents worth to turn a piece of cast iron into something equivlaent to an expensive diamond bench stone, a very pleasant surprise.

3V can be rough ground with any abrasive suitable for tool steel ( I use ruby wheel and others use ceramic wheel or belts). Makita powered water stone abrades it at an acceptable rate, but much less rapidly than high carbon steel. I will report on an optimized procedure that is cheap and fast within a week or two.

Some very preliminary work has been done using acrylic(plexiglas) as a substrate for diamond powder. The results looked promising, particularly considering the very cheap cost of an acrylic plate. Someone needs to further evaluate acrylic. I am not highly motivated to do it as I have settled in with cast iron, but if no one else does my curiosity will get the better and I will likely do it.

Re: some updated information

Wendell @ Murphy, TX

>Bill,

Do you have a favorite supplier of cheap diamond paste/powder that you would recommend? Do think phenolic sheet might be a suitable substrate for diamond paste/powder sharpening? I noticed that McFeely's is selling a Scary Sharp type system that uses phenolic resin plates to mount the sandpaper on. I need to buy some phenolic sheet to make some t*bl*s*w inserts anyway. How fast does the diamond paste/powder work compared to water stones? I noticed that it took me noticablely longer to sharpen an A2 shoulder plane blade compared to sharpening the steel in a Hirsch and Ashley Isles chisels. Thanks for the great posts on making the CPM 3V chisels.

Wendell

diamonds and substrate and table saw inserts

Bill Tindall, E. TN

>I have been pleased dealing with Reentel.com for diamond powder. Only $1 carat. We are in the process of settling on what grits are really essential. It turns out less than for grinding hard rocks. Maybe as few as 3 or 4 to go from serious material removal to near mirror.

I have such limited experience with waterstones as to not be of much value making comparisons, except to say that they are a vastly greater cost than diamonds on a plate of some sort. And I don't like the fact that they are only 8" long. Once I got used to 12" lengths i can not go back to shorter sizes.

If a plastic is used for a substrate it needs to be as hard as possible. Hence, acrylic could be the preferred choice as it is one of the hardest plastics readily available. Also it is readily available from MSC etc in an optical grade which means sufficiently flat for sharpening. I have not had any experience with phenolic resin for a diamond substrate so I can not comment. It is fairly hard.

Amen to the great difference in abrasion resistance of modern tools steels compared to simple carbon steel. It is a simple fact that the alloy carbides are greatly harder and hence more abrasion resistant than iron carbide.

I think poly(ethylene) or poly(propylene) makes a superior insert. Slick and sufficiently stiff. 1/2" sheets avaialbe from MSC.