How to make your own wedge blade

Why?

One interesting type of vintage razor are the Lather Catchers invented by the Kampfe brothers in 1880. While later models of those razors can be used with modern SE blades, older razors need to be used with a “wedge blade”. Despite the name, they are usually not true wedge blades, but hollow ground blades. Here is an image of a modern GEM blade next to a vintage wedge blade. They differ quite a bit in prifile, but are very similar in width and length:

A good indication if an old lather catcher requires wedge blades is the lack of blade stops. Here are two exapmles — a German made Comfort lather catcher without blade stops and a Star razor with blade stops.

Wedge blades are securely held in place because of their thickness, modern SE blades aren't. Another reason to use a wedge blade could be that your lather catcher has blade stops, but they have been worn down and won't stop a modern blade anymore. Yet another reason may be that you think a modern GEM blade gives the wrong shaving angle when used in a vintage lather catcher.

Why not use wedge blades?

So why not use a wedge blade in your lather catcher? Well, firstly you might not have a wedge blade. Many vintage lather catchers you can find, come without the original blades. Even if they do, the blades won't be in a shave-ready condition. They may be rusty, have nicks in the blade's edge and even in the best case they need to be honed (sharpened) by someone who knows what they are doing. Even then, the blades need to be stropped to keep them in shave-ready condition and you might not have the means to do that.

I have a lather catcher, but no wedge blade. What now?

You can either put the lather catcher in a display cabinet and admire it from afar, or you make your own wedge blade. It's not that difficult.

A quick, simple and cheap method to make a mock wedge blade is to put layers of electrical tape on a GEM blade until the shape resembles a wedge blade. Cut off excess tape at the back and the sides with a pair of scissors. What you get looks like this:

This works well, but the surface of the tape can be quite slippery and you need to make sure the blade doesn't move around inside the head.

If you have an old wedge blade for your razor, but it is not shave ready, you can try to use it as a shim for a modern GEM blade. Put the GEM blade on top of the wedge blade and insert both into your razor. Make sure that the cutting edge of the wedge blade is further back than that of the GEM blade.

Why not design a shim made from plastic or rubber, with small protrusions that hold a GEM blade securely? Something like this:

Someone actually did exactly this and published the design on this web site. You can order the design on that web site and it will be 3D-printed by someone near you and delivered to your door. I ordered five and paid about $10/£8 delivered. Not too bad.

You put the GEM blade onto the shim and insert both into your razor. It's not perfect (the combined shim and blade is not thick enough), but it does a decent job.

I got decent shaves using the above adapter, but I thought there was room for improvement, so I decided to learn how to create designs for 3D printers and I designed my own adapters. For those who are interested, the software I used to design the adapters is OpenSCAD. This program suits me, because defining a model in OpenSCAD is like writing a computer program. Other software is available and may be more to your taste. Make sure the software can export your design as an ‘STL’ file. That is what most 3D printing services want.

My first design was a rather narrow one for despined GEM blades:

I thought there was room for improvement still, so the second iteration had interlocking teeth at the back and was made from a rubber like material. Again, this was a design for despined GEM blades.

This didn't work too well, because the material was far too flexible and wouldn't adhere to the GEM blade well enough. Attempt number three was for GEM blades with the spine on.

This attempt was not very successful either. The space for the spine was not large enough and the combination of adapters and blade would not stay together.
On to attempt number four, this time printed in transparent resin with a slightly enlarged space for the spine.