DIY parting tool

[Norm Zax]

Hello folks,
Please read along and tell me if this sounds feasable:
* take a simple yet wide (cheap) kitchen knife
* grind the sharp edge flat (about 1/8 inch back)
* grind the pointy end back about 1/2 inch forming a 45 deg slant (ex-sharp edge protruding)
* use as 1/16" parting tool
any flaws in this thinking? should the grinding all be square edges? why do they put flutes on the lower side of market parting tools if this side doesnt even come in contact with the wood?
thx,
Norm

[Robert McGowen]

Hi Norm,

I have good insurance, my wife is an R.N., and we live fairly close to an emergency room, but I still don't really feel that this would be the best plan of attack. The main issue would be that the tang of the knife is not designed for the pressure that would be exerted on it and would probably snap. This would, of course, leave the end of the knife blade in contact with the wood and turn it into a 100 mph projectile. You can probably find a very cheap parting tool for less than $10 and just grind away on it until it is as thin as you want it to be. I only have 9 1/2 fingers due to woodworking though, so I could be wrong. :D

[Glenn Hodges]

Norm, as a blacksmith I can attest that we have not always had access to the type of steel we are now using. The type of steel in the knife you are suggesting to use as a parting tool would determine its practicality. If it is a basic old carbon kitchen butcher knife it might work fine. Let us know. I used an old chisel I found in a junk shop and it would not hold an edge. It was not worth rehardening so I bought a new parting tool.

[Mike Marcade]

http://www.homedepot.com/catalog/productImage/ae110089-6e4e-435c-a786-e7e7dca265fa_300.jpg

:D:D:D

[Gordon Seto]

* take a simple yet wide (cheap) kitchen knife


Norm,

The only thing I am not comfortable is the "cheap". Usually when something is cheap, there must be a reason.

I am not sure about the wide part. The wider the blade, the greater the contact area, more heat, more drag. When it grabs the blade, I am afraid the thin blade would twist. You still need to cut in steps and leave relief for deeper cuts. Keep in mind the thin parting tool is mostly used for saving wood so you would have a better grain match. Know the limitations.

I would start with a good quality knife from yard sale, flea market. Pay attention to how strong the tang was made.

In AAW video "Skill Building Projects" by Mark St. Leger, he used a butter knife to make one. Several members in our Clubs did that and brags about them.
I think I will also grind away the sharp edge of the whole knife. Of course, YMMV.

[Bernie Weishapl]

I found some heavy stainless steel steak knives for 50 cents at a garage sale. They are a little over a 1/16" thick and have a heavy handle on them. They have worked well as thin parting tools for ornaments, mini birdhouses, etc.

[Don Orr]

I did exactly as you described Norm ans it works fine. I wish I had not made it so short though. If you have a knife that is thicker on one side, grind the front angle so that the thickest part of the blade is on the tool rest, it will help keep it from binding too much. Most of these knives have tangs that go all the way through the handle so they should be strong enough.

[Allen Neighbors]

Norm, I used an Old Hickory butcher knife. I ground the sharp edge flat along the length of the blade, and then relieved the corners of the flat, just so it wouldn't mar the toolrest. I drilled out the brads that held the handles on, and mounted it in a 12" handle that I made. That extra length allows me to hold it under my arm, and use the other hand to catch the piece I'm parting off.
What you say sounds like it would work well. Just make the cutting point to be slightly below the center of the blade... this will lower the center of gravity, so to speak, and help keep it from twisting. Does this make sense?

[Ben Gastfriend]

I've made parting tools out of about everything. The kitchen knife solution worked, but I had to take it to the grinder often. I settled for a piece of 1/8 steel strip from the hardware store, and hardened it, and that's worked for me better that the knife.

[Richard Madison]

Norm,
Made one about 15 years ago from a long, thin carving knife, less than 1/8" thick. The steel goes all the way through the handle. It was a good set of knives, but my wife hated them. I ground the sharp edge to a rounded edge, ground the end to a point at thickest place, about 90 degree included angle. Works equally well right side up or upside down. Requires regular sharpening, is about 2" (maybe 3") shorter than it was originally, and is still the only parting tool I use.

I want to make one from a section cut from a contractors narrow kerf carbide saw blade (with a single carbide tooth), but cannot cut the saw blade at present. Could always "unbraze" the tooth and braze it to something else, but it is not real close to the top of the project list.

[Curt Fuller]

* take a simple yet wide (cheap) kitchen knife
* grind the sharp edge flat (about 1/8 inch back)
* grind the pointy end back about 1/2 inch forming a 45 deg slant (ex-sharp edge protruding)
* use as 1/16" parting tool
any flaws in this thinking? should the grinding all be square edges? why do they put flutes on the lower side of market parting tools if this side doesnt even come in contact with the wood?
thx,
Norm

I hope its a good idea because I use one that sounds about like what you're describing. And I've come to like it more than my store bought parting tool. I also ran the cutting edge across my grinder to take the edge off just so I wouldn't cut my hand in any freakish accident with it. The tapered edge of the knife works in the same way as the flutes on a fancy parting tool by being narrower than the actual cutting surface and reducing drag if you're cutting very deep.

[Alex Elias]

I bought one at CSUSA and end of story.

[Terry Quiram]

Do you have a machine shop in your area? Ask them for an old worn out hack saw blade. The industrial versions are 1/16 thick and make great parting tools. I have made about 20. Use Gorilla glue to attach a the handle sides.

[Bill Noce]

I have used the butter parting tool for many years since I first saw Mark St. Leger do a demo using one. Also like Terry when I was working I got all the broken 1 1/2" hack saw blades ground the teeth off which were HSS and made some out of them for my club and a few members like the Chris Stott parting tool.

[robert hainstock]

a little drastic Mike?:eek::eek:
Bob

[David Wilhelm]

The hack saw blades work good. I have a neat 1/8 made out off 12" saw blade. Not sure what the tooth count was but it was fine and i left two on this one. It works great I think one with a single would work just as good if not better.

[Joyce Baldauf]

Do you have a machine shop in your area? Ask them for an old worn out hack saw blade. The industrial versions are 1/16 thick and make great parting tools. I have made about 20. Use Gorilla glue to attach a the handle sides.

Or a foundry. They use these too and they make great thin parting tools.

[Jim Underwood]

I've made a few out of some spring steel strap off a 50 yr old Yates American End Matchers. They'd break occasionally, and we'd replace 'em with another length off of a 100' roll ($400 for the roll if I remember correctly). I'd take the broken strap which appears to be air hardening steel of some sort, and make parting tools that are about .052" thick. It's a real bugger trying to drill the stuff. I burnt up a couple of standard HSS drills before I tried carbide. Even then it doesn't drill easy. I may wind up buying some of those expensive drills from Bad Dog Tools if I make more..