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

Thanks for all the input I have been honing away on my double duck and a newer acquisition of a wade & butcher to replace the one that someone honed improperly I posted in another thread.

Following all your advise, I wet my thumb an now definately feel a kind of dragging when i brush my thumb sideways across the width of the blade. before this, my thumb slid easily and tickled a little. Now it sort of catches.

I'll try one of the blades later this afternoon, before the USC-UCLA game.








Which I hope USC wins handilly. Then thay can knock off Ohio State .

Originally Posted by mparker762

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.

Sorry, you and I had so many discussions, I thought it was you.

Originally Posted by FiReSTaRT

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 had a long thread on it, apparently not with MParker.

We actually found specific references to doing it both ways. I tried it the other way and coul feel no "grab", like the manuals describe.It does give an idication of smoothness, but you can probably do that bettr with a microscope.

What you're sanding is a calus, and I just wonder how you can continue to retain sensitivity with that there.

In any case, most of us continue to warn against any movement of the thumb along the edge. It's very dangerous, and it shouldn't even be attempted without having experience or being supervised.

Originally Posted by honedright

I think if you read the texts carefully though, and put some logic behind the reasoning for doing the thumb test in the first place, you should conclude that the test is properly done as I've described, and as the old barber taught me.

If you recall, we found specific references to doing it both ways and agreed there were two tests being done by barbers, wit yours probably being the earliest.

In any case, when I was young, I went to an old Italian barber who was a master. Since he was a young man, he had done as many shaves in a day as we d in a month. I used to see him do it all the time when he stropped. He did do a tapping motion, but there was a distinct sideways movement to the razor.

I use the test all the time when I strop or on a fine hone, in other words several times a day, and it is highly accurate. I rarely find a razor can't shave well if it passes the test.

But when a newby asks a question about how something should be done, I feel obliged to explain, in great detail, how I've learned it should be done. I know there are differences of opinion, but a new person should be well armed with as much info as possible, and then use the gray matter to decide what makes more sense.

I would definitely not reccomend a newbie try this test unless he learns it in the presence of a barber, like you did. There's too much potential for injury.

Originally Posted by kimo

Following all your advise, I wet my thumb an now definately feel a kind of dragging when i brush my thumb sideways across the width of the blade. before this, my thumb slid easily and tickled a little. Now it sort of catches.

Unfortunately, a little drag isn't enough. You'll get that even when the razor first comes off the 4K. Remember you're doing this very lightly. The razor should really grab and move sideways. You may even hear it make a ringing sound. As you do consecutive tests, you should feel the grab increase, and you'll feel a thin edge forming up. It may even feel like it's trying to shave off a thin layer of skin.

In any case, you should feel improvement as you hone and test. When the improvement stops, move on to a finer grit and continue. When you have no more grits, strop and shave.

I have an article in my gallery: "An Organized Appproach to Razor Sharpening." It discusses the thumb test and thumbnail tes in detail and describes a systematic approach to combine them so you always know the condition of a razor, from the moment you pick it up to the moment it's ready for shaving.

I hope USC wins handilly. Then thay can knock off Ohio State .

Not after the way OSU handled Michigan.

Originally Posted by Joe Lerch

We actually found specific references to doing it both ways. I tried it the other way and coul feel no "grab", like the manuals describe.It does give an idication of smoothness, but you can probably do that bettr with a microscope.
What you're sanding is a calus, and I just wonder how you can continue to retain sensitivity with that there.
In any case, most of us continue to warn against any movement of the thumb along the edge. It's very dangerous, and it shouldn't even be attempted without having experience or being supervised.

Joe, I could definitely feel the sharpness and the smoothness of the blade, which was a huge plus. The ease of digging in is a great indicator of sharpness, once you get used to it. The reason I maintain sensitivity is that I am being extra-careful and only cutting into the dead skin. Once a calus forms, I sand it down so there isn't an undue thickening of the skin. However, I agree with you that this is a dangerous way of testing the blade. One slip-up can leave you with a real bleeder. It has to be done with utmost care and not by inexperienced honers. It's being slowly phased out of my arsenal and replaced with armhair tests as I'm developing a better feel of how blades of various sharpness will behave around different areas of growth on my arms.

It seems to me as a newbe to these tests or as one who has only really seen sharp from a DE blade that both of you are using different methods to find the same thing ie. a blade capable of shaving off your fingerprint one land at a time, ore the ability to feel each groove with the edge as if it were the grand canyon and your blade is sharp enough to fall all the way to the bottom.

Originally Posted by honedright

And, if you really feel that a noob should have professional supervision while putting a straight razor to his thumb (because of potential for injury), then what about putting one to his face for the first time?? Even brushing the thumb over the edge could be a dangerous act. Anytime a straight razor touches the skin, there is a huge potential for injury.

I think any newby who is willing the risks of shaving with a straight razor is capable of handling the thumb test as I've described it.

That's entirely different. We caution newbies never to move the razor parrallel to the skin. Here you're you telling them specifically to do it.

It's not only an unwise recommendation, but it has the potential to hurt us all. These days, as soon as someone's hurt, everybody that had anything to do with it gets pulled into the suit. Your recommendation is sure to make you a target, but it is also likely to make this site one.

I just sent you a PM.

My apologies for misunderstanding. What I should have said was "the tapping part is very similar to what I do."

But I'm stuck. I tried it, with two vastly different razors. One ultra sharp and one ultra dull. I couldn't tell any difference between the two.

Despite being potentially "dangerous", without any indication of variance between vastly different edges I will stick with my method as I need a way to judge edges with small variances in edge sharpness, and without lathering up repeatedly.