Thread: Thumb Test....what is it really...new guy here

OK, my arm and head hair are too thin for the HHT. Then I hear the thumb test.

I don't get it. What am I supposed to feel? I wet my thumb, hold the razor so the blade is pointing up, perpendicular to the top of the table, I very lightly run my thumb from left to right over the blade. What am I feeling for? I have done it on blades that seemed to just skim my fingerprints.... still a not so good shave.

I have lightly touched the thumb directly down on the blade....feels sharp.... same mediocre shave.


I am not sure I understand the thumb test. Maybe just walk this somewhat confused and obviously mentally slow person through the whole thumb thing or maybe offer another different method for checking blade sharpness.

Thanks ahead of time.

Wet your thumb and run it over (by which I mean across, not with) the blade. A sharp blade will feel kind of sticky, a dull blade won't.

This test takes some calibration. I suggest getting a pack of DE or injector blades and comparing these to a dull and a shave-ready razor.

I'm kind of new to the tests too and can't really describe how sharp "feels" anyway but from my meager understanding if this:

Originally Posted by kimo

I have lightly touched the thumb directly down on the blade....feels sharp.... same mediocre shave.



Thanks ahead of time.

didn't result in you bleeding out your thumb fairly badly I would guess that the blade is far from sharp enough for good shaving.

Originally Posted by Wildtim

...didn't result in you bleeding out your thumb fairly badly I would guess that the blade is far from sharp enough for good shaving.

You might be surprised. Skin is surprisingly tough, and the skin on your hands is much tougher than the skin on your face.

Shave with the razor. Rub your thumb across your face and if your face feels baby butt smooth to your thumb, the razor is sharp......hahahahaha.

Lynn

WARNNING:
A thumb test has been decribed which involves running your thumb ALONG the edge. As far as I know, that thumb test is not the most common one used here. That would be running your thumb pad ACROSS the edge. Running it along the edge is dangerous and likely to cut you unless you're quite experienced. And the sensation is a lot less than if you do it the more common way.


COMMON WAY:

Make the thumb damp and lightly brush the thumb pad across the edge at either end and the middle (you have to pass the test in all 3 places). If the edge is dull, your thumb will easily slide across. As the edge gets sharper, it "grabs" the thumb. When it's really sharp it will move with the thumb and it may even make a ringing sound, as you pluck it. As you reach the end you can even feel a thin edge.

It takes some practice. To get a sense of what sharpness feels like, try it with a fresh single edged razor blade.

I have a similar fine hair problem. I have razors from every one of our honemeisters and not one has ever passed the HHT with my hair.

Sorry I wasn't clear on that, Joe. My thumb test is running perpendicular to the blade, not parallel to it -- same as you described. I remember the discussion where some guy preferred running his thumb along the edge, but that definitely wasn't me. Running along the blade is indeed a good recipe for serious injury, though it will tell you something about the sharpness :-(

I've edited my original post to clear up the confusion.

I actually run it along the edge and the sensation gives me a pretty good indicator of both the smoothness and the sharpness. So far I haven't suffered any injuries from it but if I hone a bunch of blades, I develop a rough spot on the thumb that needs to be sanded down lol.

I'll admit it,
I've not mastered the thumb test myself, either, perhaps I've been too rough on them for the fine level of sensitivity it requires, or I just need more practice trying.
Personally I go for the hanging hair test, so sometimes I frustrate the dickens out of myself trying to get a razor "there"....and then sometimes even after that they still need work.
John P.

I move my thumb slightly downward while it sits at a 30 degree angle, like I was shaving my thumb. The process I use sounds very similar to what honedright suggests.

As I hone, I check the edge. Your mind doesn't recall well what sharp feels like. I compare what I feel against what I felt after the last series on the hone.

I can tell the difference in each pyramid or single grit series I do. Its that reliable once you practice.

The blade sticks, it feels thinner, it feels sharper.

Once the blade is so sharp that it enters between my finger prints and gets sticky on a single land (inside the groove) it produces nice shaves.

This should give you an idea of how delicately I do this.