More than 2 or 3 days?
More than 2 or 3 days?
Time really isn't to big of a factor as to how long the blade will last. Uses is more of factor. For example if its a new blade it could be find for years. If you have used it a couple times and typically only get a three uses out of the blade and leave it for a week or two it my or my not work well for you.
The other main factor is storage condition. Was it wet when you put it away this will speed up degradation of the edge. Is it in the bathroom with a shower.
These are more of the factors to look at
Are we talking stainless or carbon steel? If it's carbon I wouldn't leave it in past shaving or it will rust quickly. If it's stainless (and most are these days) you can leave it in. I've left blades in for weeks and weeks with no problems. For long term storage make sure the blade and razor is dry and kept in a dry place. Stainless can rust if the conditions are right.
I have found that it's best for me to dry the blade, but even then I may get one extra shave out of it...so I don't consider it being worth the hassle, so I leave the blade in the razor. Some blades I get 2 shaves, some I get 3, only blade I ever gotten a good 4th shave out of are the Feather blades. I'm not sure if there are any new production carbon blades, but I just use a DE here and there when in a rush. You can't rush a straight razor, I found out years ago...
I don't leave any blade in a safety razor. I rinse it and set it off to the side. Making sure all of the residue is off of the cutting edge. Wash out the safety razor too. I've seen stainless ( stains less) blades rust in a safety razor head and leave rust in the head. Both in chrome plated brass, and in stainless heads.
I have four DEs in my rotation. I don't remove the blades after shaving, I just loosen the head, rinse thoroughly and blow out the excess moisture. Don't have a problem with rust using stainless blades.
I go by shaves, not by time. 2 or 3 shaves max, I don't care if takes 6 months to get them. Of course, if you notice any rust issues it'll be time to change it, but I never have any problems with it. ;)
I agree that storage is the main consideration - I've had packs of blades go rusty just from having the cellophane wrapper off or the cardboard pack open, kept in a drawer in a very poorly ventilated shower room that suffered from damp anyway. I'm glad to say that the room is no longer a factor as I moved out of the place, but even now I tend not to keep blades in the bathroom at all if I can help it - I keep them in a cigar box in my bedside cabinet now.
I'd imagine that if I'd shaved once with a blade and left it a few days in my bathroom I might get 2 more shaves out of it if I'm lucky (I've got quite sensitive skin so I like to change blades frequently, so your experience may be different). I generally don't put a new blade in unless I'm going to shave, so I'm not sure how long a blade out of its pack and in a razor will last.
I don't leave blades in the razor. Ever.
I got myself a small mint tin that's a little wider and longer than a blade and about 3/4" high. In it, I put a small Silica Gel packet (the kind they pack with electronics to keep them dry). This is my "drying box".
After each shave and as part of cleaning up the place to avoid the wrath of SWMBO, I put a small linen towel on the bathroom counter. I rinse the blade under hot water and shake it off. I then drop it on the towel and fold the towel over the blade. I press down to just "blot" the blade dry -- no wiping. Once it's blotted, I drop it in the drying box until it's time for the next shave. I also use the linen towel to wipe down the razor to help keep it free from soap residue.
I have used Treet carbon steel blades for three shaves, and Feathers for 6 shaves. I know everyone's mileage may vary, but when I started with DE razors, I kept the blade in the razor and did not get that many shaves from a blade.
Sounds a lot more complicated than it really is. Try it.
Since I live in Arizona where the air is always dry, it's never been an issue because any moisture evaporates quickly. The only exception was some carbon steel SE blades that I learned after one use to always take those out and blot them dry because they rust quickly.
After shaving, I rinse the razor, with the blade still in it, then I ever so gently put it on the counter and walk away. I live in the humid south east of the U.S. and this routine has served me well.
Well I guess it's true that YMMV.
And I can also see the common sense of the climate in your part of the world being a factor. I am in Alberta and it's usually quite dry here.
That being said, I still found that I avoid problems and (perhaps) extend the blade's life (albeit slightly) by keeping it dry and separate from the razor.
Bottom line is YMMV and "to each his own".
I swap blades weekly, just to keep track of things. works pretty well for me, I've found that after a week I start loosing quality regardless of shaves, so thats sort of the metric I use, I prefer blades that will get 6-7 shaves. I get a little rust in my head razor which is a cheapy gillette 7oclock plastic. but its generally on the alignment hole of the blade, or the corner "wings" I started off very pedantic about it, but quickly found that my laziness wasn't punished, so I stopped worrying. Even where I live now where everything clothes and couches go mouldy if you are not careful, rust on my razors has not been a problem.