"Trimming the hedges"

[FloorPizza]

OK, this first part is going to fall into the TMI category, but oh well... I have hairy arms. That said, I have put my wookiee-like guns (OK, more like pea shooters) to good use; they're great for testing blade sharpness. It's a variation of the HHT: the TTH or "Trimming the Hedges" test.

Holding the blade about half an inch above my arm (so the cutting edge is half an inch above the skin), I move the blade parallel to my arm. If the blade successfully "trims the hedges", it's pretty darn sharp. You can also tell by the amount of tug before the hair cuts how sharp the blade is. Too much tugging means a ragged edge, and the hair got caught in a "tooth". When you can see and hear the hairs being cut with no tug...yeah, that's sharp.

[hoglahoo]

Good observation! I do the same thing, or at least a variation of it. I start with the coarse hairs on top and gradually move to the underside for testing a finer edge

[FloorPizza]

Good observation! I do the same thing, or at least a variation of it. I start with the coarse hairs on top and gradually move to the underside for testing a finer edge

Good idea, and a new goal to shoot for. After reading your post, I tried the finer hairs with all my blades and not one of them would pass. Back to it...

[gugi]

Yes, as you noticed it all depends on the hair, so while most people end up learning how a sharp edge should cut their hairs, it's really not directly transferable from one person to the next.
The only real test is the actual shave, but all these others are good to get us in the region.

[FloorPizza]

Yes, as you noticed it all depends on the hair, so while most people end up learning how a sharp edge should cut their hairs, it's really not directly transferable from one person to the next.
The only real test is the actual shave, but all these others are good to get us in the region.

My first and only straight shave (last night) was with a blade that would not pass the HHT or the TTH test. It wasn't bad at all, but it wasn't sharp enough to go ATG. Now I have three razors all sharp enough to pass the HHT and TTH along the entire length of the blade. I can't wait to compare tonight's shave with a HHT-passing razor vs. last night's with one that wouldn't.

[FloorPizza]

I just did a HHT and a trimming the hedges test on a brand new Derby DE blade. Surprisingly, it wouldn't pass a HHT on the finer under side of the arm hairs, so I'm not feeling too bad about my straights not passing on those, either. All three of my sharpened straights (out of six I own) are now passing all the sharpness tests at a level very comparable to a Derby DE blade. I figure that's probably about as sharp as I can hope to get. I gotta go take my seven year old trick or treating, then the shave test!