My guess would be that your blade angle is too steep. Possibly the biggest difference between DE and SE shaving is blade angle. SE's require a very shallow angle - the cap should be almost flat against your face.
In fact, a good way to establish blade angle is to start with the cap actually flat against your face, and raise it up just enough to cut whiskers.
If the blade angle is too steep you are scraping your face with the blade, hence the irritation.
The 1912 is a great razor (I used one myself this morning). As far as agressiveness, I find it to be nowhere near an R41, perhaps closer to a Mercur 34C.
I consider a Gem Micromatic Open Comb to be in the same league as an R41. As always, YMMV
Another possibility that just occurred to me is that if this is your first shave with the 1912 and you are using stainless steel blades, those tend to be a little harsh for the first couple of shaves. Then they mellow out.
--Bob
What blade did you use? You might find blades harsh for 2 shaves and then settle down into something close to ideal.
I agree about the shaving angle, but I'd also suggest that, if you're using stainless blades, try carbon steel blades - they're much gentler.
I agree about the shaving angle, but I'd also suggest that, if you're using stainless blades, try carbon steel blades - they're much gentler.
+1. Also you might want to try both a GEM PTFE SS and a Carbon Steel blade. Though the GEM PTFE SS blade is the most popular among members, it was consistently tearing my face up. Fortunately I had a single carbon steel blade and though the first shave was a tad rough (I didn't realize how sharp these are), it has provided me with some very smooth and close shaves. So for me the Carbon steel works much better than the coated stainless steel one. Now I am ruing having bought 500+ coated SS blades which I may not use.
+1. True for me.