Question about two oft-repeated maxims

I have a question about two things that seem to be repeated here rather frequently but don't make sense to my mind; I'd appreciate it if someone could explain.

The first is that hollow ground razors can flex on your skin while shaving. Most of my razors are hollow ground and seem very sturdy. Also, if the only pressure we're applying is sufficient to shave off the cream, how could that possibly be sufficient pressure to flex a blade? It would have to be as thin as aluminum foil. Even a DE blade, as thin as they are, shouldn't flex under such light pressure.

My second point is somewhat related. I've seen people say that wedges and hollows sometimes need a different angle to shave properly. Since only the very edge of the razor touches the face, how can the grind have any impact on the shaving angle needed? If the bevel is set and the razor honed properly, the angle for shaving should be the same regardless of grind, which seems to have more to do with honing rather than shaving.

What am I not understanding?

Relatively new, only my opinion. Find with against grain and full hollow, even with spine touching skin, that the longer stroke I make the more weepers and irritation I get. Can only think this is the angle of the hairs and flexibility of the blade almost pulling the edge in at a steeper angle. Don't get this with heavier grinds. Also find myself using steeper angles with full hollow with the grain to get as smooth a result. Again not necessary with heavier.

My 2 cents. May be utterly wrong, but this is how it appears to me. Also have rather thick hairs. Friend I got into shaving with straights doesn't find this and has noticeably thinner hairs.

Pressure to remove lather to me refers only to pressure onto face rather than forward pressure.

[QUOTE=Moonshae;1577551]Since only the very edge of the razor touches the face, how can the grind have any impact on the shaving angle needed?
/QUOTE]

This?

[QUOTE=dmnc]Pressure to remove lather to me refers only to pressure onto face rather than forward pressure./QUOTE]

Pressure applied to the face is minimal, so blade flex should cause irritation. That's exfoliating if blade is pressed hard enough to bend it. Movement across the skin also requires pressure, when combined with blade pressure on the skin aren't you pealing potatoes?

No, peeling my face. May just be beginnerness, but still struggle with that atg with full hollows, but no problem with less hollow. Even with spine touching skin. Especially with longer strokes. My thinking is this must be from the blade flexing. Even with properly sharp edge (hatzicho, not my own) I need a decent bit of forward pressure. Could easily be me putting extra pressure on face at the same time without realising and the extra weight of heavier grinds allows me to keep both pressures down. I'm known to be wrong on normal occasions.

The very edge of a blade is about as thin a aluminum foil. That's why they can be damaged so easily and why when you look at edges under mag you see the very edge rolled and deformed when they are damaged.

All edges flex. I think the hollows do it more so it's more a degree. The thicker the razor the less it happens. A true wedge is rare but I'd bet there is some limited flex going on there too.

I'm sure one of our razor tech guys will come along with the info from "the horse's mouth".

There is a couple of things I have experienced. With a heavy blade like a near wedge, there is a certain point where the blades starts to suction on my skin, which is when it is near flat against my skin. It is almost impossible to shave like that. Of course a wetter lather and that reduces, however it still exists. I have never had that happen with a full or half hollow. So the little extra angle on wedge facilitates my against the grain shave. There is always some amount of whisker resistance that happens when shaving. I cannot see how it could be possible for it to happen any other way. When shaving the pressure needs to be forward and on the edge not pushing the blade into or tighter to the skin. I am not sure I understand the issues as presented but if I understand correctly that is my observation on the wedge angle. The fact that a full hollow flexes I have always believed to be in the realm of very tiny amount.

I did notice it on my Mastro Livi razors. RWL34 stainless is stiffer then the regular steel extra hollow blade. Mastro Livi makes reference to in when he is honing. He does not like putting finger pressure on the blade when honing because his extra hollow blades are flexible and can get uneven honing. I really noticed it when using the RWL34 blade across and against the grain. Shaves much smoother being less flexible. The factors are the steel and whether it is extra hollow, hollow or wedge. Just getting used to the type of blade used.