This is a short report on my experience with shimming. I have been using DE razors for about 28 years. Originally, I started shaving with straights but they are just too much of a pain and I can get just as great shaves from DEs with much more comfort.
This is my experience and opinion based on the following:
1. Visual reference.
2. Measured gap and exposure.
3. Quality of shave.
First, not all razors benefit from shimming. Second, one shim is all you need in order to experience a difference in the quality of the shave.
A DE shim is nothing but a used blade with the cutting edges removed. I will discuss to cuts: A deep cut where you end up with a narrow shim, and a shallow cut where only the sharp portion of the blade is removed.
There are three ways you can shim: By placing the narrow shim between the top cap and the blade, by using the wide shim between the blade and the bottom plate, and by placing the narrow shim under the blade.
Only razors with 'free-floating' blades will benefit from shimming. By free floating I mean any razor in where the blade is not supported on the bottom; ex. 34s, adjustables, 89s, and all their clones and copies. Razors in which the blade rests on the bottom plate, like most open comb razors, will not benefit from shimming.
A wide shim placed under the blade will not cause such a dramatic difference in blade gap in order to change the quality of the shave. However, such shim will provide more support of the blade and hence reduce flex and flutter; this is where you will feel some benefits, mostly a feel of a more precise shave. It will not make the razor more or less aggressive, just a bit smoother.
A narrow shim placed over the blade will provide a much more drastic change in the shave. Such shim will change the blade angle (by flattening the blade) and provide a bit more exposure hence making the razor more aggressive.
A narrow shim placed under the blade might make the razor a bit milder by pushing the blade more in and hence reducing exposure. This is however highly depended on the shape of the top cap.
So here is my take. If you like the way your free-floater shaves, just add a wide shim on the bottom plate. If you want a bid more aggressiveness with the benefit of added stiffness, then place the narrow shim on the top plate.
Here are some examples:
34C and 89: The narrow shim under the top plate makes the razor more aggressive but still smooth; I like this a lot as I find the 34C to be a bit too mild. A wide shim under the blade will only improve the feel of the shave without giving extra aggressiveness.
R41: A wide shim under the blade makes the razor much smother without adding extra aggressiveness, not that it needs it!
Fatip: No difference.
Ikon open comb: No difference.
39C: Very little difference, I'd leave it alone.
Vintage Tech and clones: See 34C.
Other open combs with smooth bottom plate: No difference.
I have experimented with more shims and even washers but honestly changing the gap on most razors will result in a harsher shave not a closer or smoother shave. I tried two washers on my 34C and they gave it a blade gap on par with a Progress at setting 5 and the shave was very, very aggressive but not smooth at all.
Experiment on your own and report your results!
This is my experience and opinion based on the following:
1. Visual reference.
2. Measured gap and exposure.
3. Quality of shave.
First, not all razors benefit from shimming. Second, one shim is all you need in order to experience a difference in the quality of the shave.
A DE shim is nothing but a used blade with the cutting edges removed. I will discuss to cuts: A deep cut where you end up with a narrow shim, and a shallow cut where only the sharp portion of the blade is removed.
There are three ways you can shim: By placing the narrow shim between the top cap and the blade, by using the wide shim between the blade and the bottom plate, and by placing the narrow shim under the blade.
Only razors with 'free-floating' blades will benefit from shimming. By free floating I mean any razor in where the blade is not supported on the bottom; ex. 34s, adjustables, 89s, and all their clones and copies. Razors in which the blade rests on the bottom plate, like most open comb razors, will not benefit from shimming.
A wide shim placed under the blade will not cause such a dramatic difference in blade gap in order to change the quality of the shave. However, such shim will provide more support of the blade and hence reduce flex and flutter; this is where you will feel some benefits, mostly a feel of a more precise shave. It will not make the razor more or less aggressive, just a bit smoother.
A narrow shim placed over the blade will provide a much more drastic change in the shave. Such shim will change the blade angle (by flattening the blade) and provide a bit more exposure hence making the razor more aggressive.
A narrow shim placed under the blade might make the razor a bit milder by pushing the blade more in and hence reducing exposure. This is however highly depended on the shape of the top cap.
So here is my take. If you like the way your free-floater shaves, just add a wide shim on the bottom plate. If you want a bid more aggressiveness with the benefit of added stiffness, then place the narrow shim on the top plate.
Here are some examples:
34C and 89: The narrow shim under the top plate makes the razor more aggressive but still smooth; I like this a lot as I find the 34C to be a bit too mild. A wide shim under the blade will only improve the feel of the shave without giving extra aggressiveness.
R41: A wide shim under the blade makes the razor much smother without adding extra aggressiveness, not that it needs it!
Fatip: No difference.
Ikon open comb: No difference.
39C: Very little difference, I'd leave it alone.
Vintage Tech and clones: See 34C.
Other open combs with smooth bottom plate: No difference.
I have experimented with more shims and even washers but honestly changing the gap on most razors will result in a harsher shave not a closer or smoother shave. I tried two washers on my 34C and they gave it a blade gap on par with a Progress at setting 5 and the shave was very, very aggressive but not smooth at all.
Experiment on your own and report your results!
