Thread: Thumbpad test (TPT) questions

ACROSS??? Thumb...across...the blade?

Ut-oh.........


Scott

Drawing my thumb across the blade has never told me anything when I do that. Well, eh, actually some "pling" and others don't. But apart from that, I really need to make small motions along the blade with my finger tip barely touching. It's the only way I asses the cutting qualities of an edge.
I think this might be one of those 'Your mileage may vary" things.

If a blade is truly razor sharp, with the way I perform the test, it feels like if it's covered with caramel, or some other sticky substance. It sort of sucks itself into the skin, and because of that, a little resistance can be felt upon pushing your finger tip forward along the edge. This sensation shows some variances in relation with the degree of sharpness. Only experience can learn you to read the finer nuances of that kind of blade gauging. I often compare between the blade in question and another blade of known sharpness.

That's the way I do this and it works for me.
I'm sure Xman's method works for others as well.

Best regards,

Bart.

I like that "caramel" description a lot, Bart, thanks for that. I think it's a sensitivity thing...I am just not attuned enough into what I should be feeling at this point. I will try with my fingertips instead of my thumbpad as you suggested, and try to feel the stickiness you describe. Since this are new, unopened double-edge blades I'm sure the stickiness is there, I'm just too clumsy to pick up on it right now.

Many thanks for the replies, all!

Originally Posted by Bart

Drawing my thumb across the blade has never told me anything when I do that. Well, eh, actually some "pling" and others don't. But apart from that, I really need to make small motions along the blade with my finger tip barely touching. It's the only way I asses the cutting qualities of an edge.
I think this might be one of those 'Your mileage may vary" things.

If a blade is truly razor sharp, with the way I perform the test, it feels like if it's covered with caramel, or some other sticky substance. It sort of sucks itself into the skin, and because of that, a little resistance can be felt upon pushing your finger tip forward along the edge. This sensation shows some variances in relation with the degree of sharpness. Only experience can learn you to read the finer nuances of that kind of blade gauging. I often compare between the blade in question and another blade of known sharpness.

That's the way I do this and it works for me.
I'm sure Xman's method works for others as well.

Best regards,

Bart.

The Thumb-Along-the Blade method is the one taught in the classic barber manuals. The Thumb-Across, I believe, comes from what you get when two different, but related, disciplines (knives and straight razors) mix.

While strumming your thumb across the blade probably does provide some type of sensory information, it's probably not THE specific information that best evaluates the keeness of a just stropped edge of a straight razor which is the whole reason for the TPT.


Scott

I will often use my thumb to test one way and then my fingers to test the other way. For me this was something that took a lot of time to develop the feel for what I was looking for. Sometimes I just need to touch the edge and not move across the edge. I often do this test before I strop to determine if I use the diamond pasted side first or not.

Originally Posted by honedright

ACROSS??? Thumb...across...the blade?

Ut-oh.........


Scott

The motion I teached from my grandfather (he was a barber from 1918) for TPT is a diagonal motion mostly across and little along like SWW-NNE.
I dont moist my thumb and I use a very very light touch, almost no touch!

Originally Posted by Yannis

The motion I teached from my grandfather (he was a barber from 1918) for TPT is a diagonal motion mostly across and little along like SWW-NNE.
I dont moist my thumb and I use a very very light touch, almost no touch!

Yes, I've seen barbers do this as well. Probably a variation of the classic method which I've also seen barbers do.

But the same barber who showed me the diagonal variant agreed absolutely not across the edge with the thumb - "that's for knives" he said, "not straight razors."


Scott

Originally Posted by Bart

I'm sure Xman's method works for others as well.

Certainly YMMV. Always safe though, right?

Originally Posted by honedright

... evaluates the keeness of a just stropped edge of a straight razor which is the whole reason for the TPT.

I definitely use the TPT to evaluate my honing progress which does likely contradict with the ancient wisdom.

X