Topic: Building a Marking Knife

[Ken (OP)]

For 'fine' woodworking a good marking knife is a really handy tool to have in your inventory because it can give you a clean precise line when doing layouts for your cuts. Pencils and other marking devices are OK for woodwork where you're not overly concerned about the appearance of the fit and finish, but if you want the work to approach a better quality level then your layouts need to be of a good quality level to get the project off to a good start.

There are lots of ways to get the job done, a good pocket knife would work, an X-Acto knife (more about this one later!!!)... and, you could always buy a marking knife from places that sale tools for woodworking. But, for me buying one is out of the question because of the cost, a decent knife runs $12-15 and the nice ones run up to $50 and more.
So what to do???

Make one of course!
   


You can see more pictures in the Gallery.

[Ken (OP)]

So here's how I built my marking knife.

But first... did I mention my dislike for X-Acto knifes? They are nice for some stuff I guess, but as a marking knife they just suck! At least they do for me! They are flimsy and tend to fall apart at the most inopportune times and as you can see in this picture they can cause some serious damage to your finger... if you look at that X-Acto blade carefully you'll see a little red tinge on the blade's edge and yes that's from me!   


GrandMa Kay had to patch me finger and she did a great job.  :2thumbs:

[Ken (OP)]

OK, so here goes...

I looked at lots of plans and examples found on the internet, including several I found on my favorite woodworking site Sawmill Creek, but my favorite design comes from one of my woodworking magazines, ShopNotes issue #117.

The little chunk of metal came from an eight foot long piece that cost me $1.50 at my local salvage yard, so that small bit is worth maybe 4-5 cents, but the wood is 'Purpleheart' and that is expensive stuff so that small piece cost about $1.00.




In this next image the magazine is showing how to layout and cut the steel and as you can see my piece has some layout fluid applied and the layout lines have been scribed. In the mag picture they show using a hacksaw to cut the metal to shape and that's what I did.

[Ken (OP)]

After some work with my hacksaw and a file the blade is starting to take shape. Now it's time for the real work... final shaping and sharpening are done using the 'Scary Sharp' method, that's the use of sandpaper to sharpen a blade. You start with a course grit paper and work up to an ultra-fine grit, in this case a 2000 grit paper that's on another glass panel that's not showing in this picture.



Once the blade shaping is good and the first round of sharpening is done it's time for a little heat-treating!
First, heat the blade to a bright orange and then dip it in oil for a quench. I'm using some leftover peanut oil that we had used to deep fry a turkey... smells good all over again.
 


Then you cook it for one hour at 350 degrees and let it cool naturally, this is being done in my second hand store toaster oven... works great.

[Ken (OP)]

We're in the final stages now.

After doing the heat treating it's time to redo the sharpening and to polish out the metal to a 'mirror' finish. I'm also working the Purpleheart into the shape of the handle portion of the knife.



Then comes the glue-up.


And drilling a few holes.


And then pining some brass rivets. (... made from a brass welding rod.)


And that takes us to the finished knife that you saw in the first post.


This was a fun build and I learned some things along the way so maybe I'm build a full set of these marking knifes once my finger heals up... did I mention that I do not like X-Acto knifes???  :08:

[Lesmond]

Nice work Ken, I used an old kitchen knife that had a wooden handle, I just cut the blade down to size, then sharpened it down with my grinder (an electric one with two grind stones) and then use an oil stone like this one below,  and get a nice sharp edge on it.


this is like my bench grinder


Yes I agree those X-Acto knifes are dangerous indeed :yikes:

[Skhilled]

Great work!

[Burgundyrose]

That is a beautiful knife! Great Job!

[Ken (OP)]

Thanks Rose, Steve and Les.  :disted: