Thread: Introduction and Forging a Razor from a File

Angle is simple: you know the with of the blade and the thickness of the spine.
You'll want to 'scoop out' some metal before HT, because hollowing out a piece of full hardened steel will be a lot more time consuming.You have about the correct thickness at the edge left for heat treatment.

Also when hollowing out, especially after heat treatment, the diameter of the hollow should be a little bigger than the hollow of the wheel. You rock the blade from spine to edge on the wheel a bit, if you know what I mean. The reason is that that will greatly slow down the heat buildup. If you have a hollow with the same diameter as the wheel, the entire hollow will make contact and the heat buildup will be very fast. I admit I ruined a razor this way. I was regrinding an old wedge, kept the blade cool, but as soon as the hollows became the same, the blade almost instantly flashed blue near the edge.

Btw, if you are still interested in having me look at them after the post HT grinding stage, PM me for address details. I'm traveling the next couple of days so don't worry if I don't answer rightaway.

If it is any help I did a file/razor a few weeks ago. It was posted in the "gallery". Also Baldy has just posted his latest razor which also was from a file too. You have done a nice job with yours. Keep up the good work and please keep posting your work for all to admire and to imitate. I would have never had tried a file if it wasn't for the posts that I have found on SRP. I am sure you will find a lot of support and knowledge at SRP.
OOPS! WELCOME my friend!! We hope to see more from you.
Ray

For the proper angle use the ratio method of blade width divided by spine thickness. The ratio should not exceed 4:1 . An example is a blade width of 1" should have a spine thickness of 1/4" or greater. This will result in an angle that will minimize the width of the bevel and make it easier to hone and have a stronger bevel that is less prone to micro-chipping at the higher grits. The historical ratios are 3.5:1 up to 4:1.

Hope this helps

Thank you Ray. It took me awhile to navigate the forum, but I found the thread with your razor from a file build. Very nicely done, I really like the photo showing the phone book and how you kept the old file name & logo! I will update my progress, but from the feedback I've gotten I am going to hold off on these razors until I have been able to buy or build a 2x72. I found a Bader Pro for sale at a reasonable price. If it's still available in a couple of weeks I should be able to get it. If not I'll build my own, there's a lot of good information out there on doing so.

Thanks Randy for the explanation on calculating the angle and the recommended ratios, that is very helpful. Everyone has been a great help so far. I'll keep y'all updated and take lots of pictures along the way, including the grinder build.

If you haven't already found it, USA Knifemakers in Minnesota has a kit and many individual parts for a no-weld 2x72. Go for some kind of variable speed control, either multiple pulleys, or, best, a phase converter speed control. If you want more info on phase converters, PM me.

I've been on the USA Knifemakers site quite a bit today and also downloaded the free grinder plans from SRP to make a KMG 3-speed clone. I would prefer to weld an all steel frame together, but should I be concerned about possible heat distortion to the frame and jacking the alignment? For that reason is it preferable to do a no-weld design? I'd be using a Lincoln Tombstone 220 arc as I don't have a MIG or TIG going w/ cold rolled steel. Could peen the welds and keep moving to minimize distortion.

Sorry, I'm sure this is covered somewhere multiple times in the forum.

The main area to be concerned about distortion is in the tube that the bar with the wheels on it slides into. When you weld it, put the bar into it, and add paper spacers. This will take care of the heat shrinkage issue. You may have to use an hydraulic press to remove the bar after welding. The Guild of Metalsmiths built around 20 of them several years ago, and I was involved in the welding. They were also a KMG clone. I have a KMG, which we used to redesign several areas. Again, PM if you need help.