Thread: Thumb pad test

I'm still a beginner, having honed about 20 or so razors. But they've all turned out well. I have been very careful about what I actually try to hone, so I credit the good outcome to the folks at Solingen and Sheffield!

I use the TPT at the bevel-setting stage, since I have a pretty good sense of what a wicked-sharp knife feels like on my thumbpad and the TNT for seeing how the edge is coming up.

I had not heard of the TPT for testing shave-readiness, though. I usually drop any tests except hair-cutting (arm and leg hair) once the bevel seems set.

Does anyone else use the TPT for shave-readiness? Is there a chance the TPT could potentially harm the very fine shaving edge of a razor coming off the finishing hones?

I know it can be done as a shave ready test. Pretty sure Lynn can tell you what hone you finished on with his thumb.

Originally Posted by Deckard

I must confess to using a 100x hand held microscope on occasion, but this will ony tell me if I'm past any micro chipping, nothing about the edge.

i am waiting on a hand held microscope from Amazon.com (real cheap too) for the elimination of micro chipping. A guy on the reviews said he uses one for seeing the scratch patterns on blades so I thought it would do the job nicely. I found a 50mm lens turned round is too difficult for seeing the edge properly.I am also just curious to see the patterns at each stage.

This is very instructive indeed. After using the TPT to check the bevel as it develops, I have tended to avoid doing anything with the edge except try to cut hair. Maybe I'll start experimenting with the TPT at the 3K and higher.

Originally Posted by holli4pirating

I know it can be done as a shave ready test. Pretty sure Lynn can tell you what hone you finished on with his thumb.

When I was starting out Randy told me to use a new DE to learn what a sharp edge felt like on the thumb pad. In bevel setting I examine the edge with a 30x eye loupe and/or a 45x stereo scope. I use the TNT initially to gauge where it is. Once the edge digs in smoothly and grabs for the full length of the blade I do not use the TNT again. I continue with the bevel set using the TPT as Randy suggested to familiarize myself with it even at the bevel setting stage. I also use the hair shaving but not as much as before because my thumb pad is becoming educated.

I use the TPT all the way through to finishing with an occasional look at the edge through the eye loupe. IME the TPT does not have a detrimental effect on the edge. Regardless I always do a few more round trips after any test to undo anything I may have caused just for insurance. The photos of my thumb pad show the nicotine stains from tamping my pipe and maybe the furrows from frequent use of the TPT. Hard to take a pic in focus left handed.

Arm hair?
TPT?
Microscope?

Originally Posted by AFDavis11

Yes, that is a very good indicator. Perhaps not 100% reliable, but an important factor to consider while honing. I have read many people use this as feedback. I can't do this on a barber hone though, only on the 8K Norton.

I also have had no success with the TPT. I tried it on everything including a brand new DE blade, and all I feel is a smooth edge even with some pressure and wet... Perhaps I am too thick skinned??

Originally Posted by thorxes

I just can't seem to get any feedback from the TPT.

Does anyone else have this problem.

Whether it's a razor that's been honed by the hommies here on SRP or one that I've honed myself, not matter how smooth of a shave it gives, I can't seem to get a good baseline "feel" for the TPT.

I rely on the thumb pad test for setting bevels and have been an advocate of it for teaching new guys mainly because most guys know what a sharp pocket knife does or should feel like on the thumb pad (Or I least I thought this, think it....oh well......lol). It's that damn this thing is sharp feeling where the blade wants to grab the skin and you feel like you could cut yourself with any pressure feeling. I have been amazed at how many people I have seen running their poor thumbs up and down an edge (How do you guys do this without getting cut?) vs. a perpendicular or sideways type of motion. I have gotten very comfortable with this test because it is relatively easy and for me completely accurate. I will not move past the 1K stone until I feel that pocket knife sharp feeling. I know that I can then do the rest of my process and end up with a shaving sharp razor virtually every time.

If you want to educate your thumb pad, do this test off every stone as you hone and then do it again after stropping on your linen and after stropping on leather. Do it on a couple different strops and different finishing stones if you have them and in a very short amount of time, you will start to recognize different levels of sharpness.

Have fun,

Lynn

Are we talking about thumb across the blade? Not thumb running the length of the blade as if you were trying to cut your thumb off. Correct?

YouTube - tpt.MOV