Thread: How wide the rear of a wedge should be?

Ive made a couple scales and wedges now. I know that the wedge is barely a wedge shape and when making the wedge i put it between the scales with no pinning and see that the space at the pivot end has an inch of space when pinching the wedge in the scales. Is this about the aproximate spacing or should it be less? Now this helps to determin the wedge shape.

Main question is how do you determin the thinnest part of the wedge. The angle of the wedge (wedge shape) is simple enough to figure but this dont help with the thinnest part of it. Let say all you have is the blade. Razor came with no scales. So nothing to compare too. Sorry, i did this in a hurry. Hope its understandable.

What is your opinion?

Measure the blade at the tip, where you want the blade to hit the top of the scales. That should be the thickness of the wide part of the wedge.

Now make your wedge with the thinnest part, half the width of the wide part of the wedge. A pair of veneer calipers makes the measuring much easier. You can pick up a pair of plastic ones for a couple bucks and are great for stuff like this, where measurements are not critical.

I keep a pair in the glove box of each car, for measuring bolts and nut and thing at the hardware store.

I take the wedge when it is a small square and double stick tape it to a wood paint stir stick, then lay a piece of 100 grit sand paper on the bench and make the taper applying more pressure to one side, if you don’t have a belt sander. Just takes a minute.

This is where mocking up with small nuts and bolts really pays off, or you will need a third hand. You want to make sure everything is aligned properly and you can make adjustment to the wedge, scales or shim a crooked tang if needed. Once you pin it, you will have to un-pin if there is an issue.

Originally Posted by Gasman

Ive made a couple scales and wedges now. I know that the wedge is barely a wedge shape and when making the wedge i put it between the scales with no pinning and see that the space at the pivot end has an inch of space when pinching the wedge in the scales. Is this about the aproximate spacing or should it be less? Now this helps to determin the wedge shape.

Main question is how do you determin the thinnest part of the wedge. The angle of the wedge (wedge shape) is simple enough to figure but this dont help with the thinnest part of it. Let say all you have is the blade. Razor came with no scales. So nothing to compare too. Sorry, i did this in a hurry. Hope its understandable.

What is your opinion?

Depends on the scales and how deep you want to set the blade. The most crucial part is to get the taper correct the rest can be adjusted on the go.

The taper of the wedge should match the taper of the tang. Typically I go with the wide end of the wedge id the same as the width of the tang at the pivot hole, plus if you are using thrust washers.

I have read that theory in other posting here and other forums, and also that the wedge, at its widest, should be half the thickness of the tang at the pivot hole.

But that does not fit with many large razors, mostly Sheffield’s with thick ¼ inch and larger tangs and thin 1/16 in lead wedges.

It may be a good starting point, then adjust at mock up.

For me, one of the main factors is where, how deep I want the razor to sit in the scales, so I use that as my guide. If the wedge is as wide as the thickness of the razor, at the point I want it to hit the top of the scales, that is where it will rest.

True, that works perfect for 1/2 hollow to wedges and fails on full and extra hollow blades. It is where I started, and you are correct that it may very well wind up at 1/2 that. It all works through in the mock up. The mock up is a very important step in scale making.

I didnt take into concideration the thickness of the tang at the pivot hole. Thanks for this important point. I dont have any big razors to work on so ill go with half the thickness of the tang at pivot hole as a size to shoot for. Little more little less. And with that i can figure out the angle of the bevel so the thin end of bevel will be what it will be.
This is great info. Thanks.

Now do you agree with the spread on the scales at the pivot end being an inch with only the wedge in place at other end? Or is this a bit much?

The spread on the scales will vary a little bit with the length of the scales and the amount of taper the tang has. I would not put too much store in measuring that.

Im just trying to figure out the proper Geomitry of wedge to scale. I know ive read a few different opinions but in this manor it seems much easier to grasp. It all depends on tang size and grind if the blade.

Liking this!

RezDog if not a measurement then how do you determin this last factor? And i dont want to hear its a feel for it as i dont have that option just yet. Ha.

The way I understand the theory is, you have a given, the tang width and taper of the tang.

So, if you want an even bow, that will give you the most clearance, at the thickest part of the tang, (near the heel) the angle of the wedge, should be the same as the tang. Think of looking down on a canoe, the wedge end and tang end are the same.

But you still want the razor to fit in the scales and not hang out the bottom. That is probably a good guide and not a hard-fast rule.

If you took a measurement equal to the length of the wedge, (a 1/16 inch less, from the end of the blade to the end of the scale) and measure from the pin hole back to the tail, and use those measurements the angle would be the same.

At the least, it would make a good starting point. Based on vintage razors, there are no hard and fast rules. A lot depend on the scale material, the thickness of the scale and the flexibility of the scale material.

In the end, you want a wedge that bows the scales to clear the widest part of the tang, smooth opening and closing, allows the razor to rest in the scales where you want it to and looks good.

Using the technique, I described in the earlier post, with the angle half the width of the widest part, usually give me about ¾ to 1 inch opening, when the wedge is pinned or pinched. So you are pretty close.