Cutting Around A Template Which Blade?

[DavidL]

When cutting around a template or scribed line.

How does each knife compare to prevent the corners from "flaring out". Which is more "suitable"?

1. Clicker knife (concave profile)

2. Round knife (convex profile)

3. utility knife (straight profile)

My awl has a rounded convex point profile and can cut templates better than my sharpened utility (prevent the edges from creating that little nub).

[gmace99]

Depends what leather you are cutting.

I use me clicker on thin leather and my round knive if it is saddle flap leather

I have never used a concave blade in my clicker knife. My clicker blades are straight like my paring knife. I make my own blades out of good quality hacksaw blades.

[Art]

It is easier to see (and hence follow) a line with a head knife. For really intricate "inside" cuts, the No. 11 scalpel or a sharp pointed clicker knife is good too. For tight curves, a big head knife is hard to turn, but those small ones with the shallow profile are better. Everything has to be bleedin' sharp.

Art

[DavidL]

Thanks for the help.

I figured out the way to cut these corners by paying more detail by how i move my blade. First I took your advice art and took 5 mins to sharpen the blade to bleeding sharp. How it was before wasnt as sharp as I could of had it. When just reaching the edge I slowly tilt the blade against the template at the same time lower the blade (larger cutting surface) putting more pressure. The twist keeps the blade from moving off pattern.

I have to test it more to find out if it is the proper way.

[bgl500]

Keep in mind I don't own one or have yet to try but the industrial knife looks really useful.

https://www.youtube.com/watch?v=BptBUaXd7rM

[TinkerTailor]

One thing to consider also is the cutting surface. While they can make a more accurate cut and are the best in inside corners, pointed knives tend to dig into the surface you are cutting on, adding drag, and in the case of wood grain, causing the blade to wander.

If I am cutting on wood or any softer surface, I would use a round, or convex blade shape. It will sink into the base material less and won't tend to follow the grain as bad. If necessary, i will switch to a straight or concave for the corners.

If I am on a poly surface, I would use straight or concave all the time for accuracy.

[DavidL]

Interesting. I never considered the cutting surface to be a factor.

[howie696]

Keep in mind I don't own one or have yet to try but the industrial knife looks really useful.

https://www.youtube.com/watch?v=BptBUaXd7rM

I bought from Weaver the same knife was about half the Tandy price

[DavidL]

Heres a response I've gotten from a reputable source.

The Clicking Knife was introduced by the shoe industry & curved & straight interchangeable blades are available. When cutting firm leather, (medium to thick) the blade point penetrates the leather & the cutting is done by the area of the blade just above the tip as you pull the knife towards you.

As you can imagine only a small area of the knife is in contact with the leather, Now if you try to cut soft leather or linings with a hooked blade it results in a raged edge,but a flat blade will ensure that a long area of the blade is in contact with the materials being cut. ( That is providing you are not raising your hand to high & reducing the area of contact.

As for cutting round corners, it is impossible to cut round small corners with any knife, & your best option is to cut past the corner then cut round the rest of the pattern. you will have square corners but keeping the pattern in place you can cut round the corners afterwards. you can also chip the corners away from the edge of the pattern with a straight blade.

The Large straight knife is seldom used nowadays, The round knife is now mainly used for shaping strap points & cutting strap ends & it is used in a rocking motion on the surface of the strap & when it is used by a saddler to cut round curves free hand it is pushed & not pulled.

[Art]

Who or what is the reputable source? If you include it then you should credit it.

Art

[TwinOaks]

I disagree with the statement "As for cutting round corners, it is impossible to cut round small corners with any knife....". I've seen it and done it too many times.

That said....

If it's a really intricate pattern, you could cut it first with your swivel knife to get through the grain, then follow with whichever blade you use best to complete the cut through the flesh side. It will be a multi-pass cut, but I haven't seen any rules that state we HAVE to cut clean through something in one try.

[oltoot]

none of the above, My idea, mark aroud the template with a marking awl then you can move the piece around for best light, angle etc and cut with a round knife, my go to for just about everything

[DavidL]

Source is Francis from leatherconnection.com

Tracing with an awl first is my go to. For grained leather it is very difficult to see the line.

I simply press down with knife blade right at the corner and repeat at the end. This no seems to work best.

Edited November 29, 2015 by DavidL

[Equiplay Saddlery]

none of the above, My idea, mark aroud the template with a marking awl then you can move the piece around for best light, angle etc and cut with a round knife, my go to for just about everything

+1

[Art]

It all boils down to what you have and what you are handy with. If all you've got is a chainsaw, but you are handy with it, it will get the job done (however your sandpaper costs may increase dramatically). Experts are experts at using whatever they use; a $15 utility knife can outperform the best head knife in the right hands, and the inverse is also true. It just helps if whatever you have is sharp.

Art

[TheCyberwolfe]

The surest way for me to screw something up is to try and cut against a template - sure as <whatever>, that template will slip and I'll waste a couple inches of leather doing it over. So, my method is to trace onto the leather and then cut. If I'm having trouble seeing my lines or just want to make sure I know where I'm cutting, I turn my template and my leather grain-side down and trace with a ball-point pen on the flesh side (gettin' old sucks...)

And if anyone tries to tell you a true corner can't be cut with a straight knife, have them watch the video on Round / Head knife use on the Springfield Leather channel. Denny will prove otherwise.

[JamesR]

I cut inside corners with a hole punch or a round end punch. Although it might not work if the hole radius is different then the pattern.

I then make my knife cuts to meet the edge of the hole.

I also bought corner cutters from Springfield that work very well.

[johnv474]

I vote for the clicker knife as well, for the reasons said by others, and for its manueverability.

If the template is just straight lines,like for a briefcase, that maneuverability may not add any value.

Oh, and following up on what JamesR just said above, it' possible to use a round punch to cut exterior corners too. If you buy a spare belt punch (round), then file down part of the circle, you can have a corner punch for any small radius. I know Osborne makes those up to 3/4" diameter.

[Lippy]

FYI, the industrial knife sold by Tandy is actually made by Warren Cutlery. Nice people and you can buy direct from them. https://www.warrencutlery.com

Here's an interesting discussion about the traditional clicker knife. http://halflightbindery.com/journal/2014/3/28/66mqiv4g4mnt7clbkahnulb3nml752

Perhaps there's a reason the "traditional" head knife and clicker knife are still around. The old school leather workers must have tried many different knife styles and those two have survived. Guessed they worked!

Cheers!

[Kulafarmer]

FYI, the industrial knife sold by Tandy is actually made by Warren Cutlery. Nice people and you can buy direct from them. https://www.warrencutlery.com

Here's an interesting discussion about the traditional clicker knife. http://halflightbindery.com/journal/2014/3/28/66mqiv4g4mnt7clbkahnulb3nml752

Perhaps there's a reason the "traditional" head knife and clicker knife are still around. The old school leather workers must have tried many different knife styles and those two have survived. Guessed they worked!

Cheers!

Thanks for the link to Warren,

Excellent products