Thread: Well Ive taken the first steps of practice. Its not much but Im excited to do more.

All of these are crap flat rod I picked up at Home Depot after reading a post from Lewis recommending people practice using it when they learn to use a belt grinder.

Im glad I listened. It worked perfectly and clearly showed where I was uneven and leaving facets. I have alot more practice to do before I would feel comfortable taking it to quality steel.

Try 1:


Try 2:



Try 3:


This stuff rusts crazy fast luckily this isnt what razors are made of or everyones would be rusted to hell. For three hours of play and experimentation Im pretty happy, and terribly excited to practice more and get the grinding process down. Thanks for all the people who have posted helpful tips that I picked up on randomly.

Are you trying this at different speeds and grits too ?

Originally Posted by 10Pups

Are you trying this at different speeds and grits too ?

Yes I went from a 50 grit up to a 400 with a few belts in between. The machine also has a dial with 10-90 on with which correlates to speed somehow. I would be lying if I knew what it meant. Any tips would leave me obliged. The machine im using is not mine but rather a few friends who I have become close with over the years through business. They have quite the set up and next time im there I will ask what the numbers equal in speed. I know this matters but I figured I could learn how to grind evenly on crap steel before then. I had a hard time finding any list of specific points I should be aiming for.

Keep in mind that good steel will be a lot tougher and abrasion resistant.
Especially after heat treatment. When you feel confident enough to start with good steel, you should repeat this exercise with hardened stock, just to give you an idea. It will also help you to determine how fast is too fast when colors appear on the surface.

Originally Posted by Bruno

It will also help you to determine how fast is too fast when colors appear on the surface.

Thanks for the tip Bruno! That coloring indicated when the blade becomes too hot right? Which means temper loss?

Yes. During the rough grinding stage, before heat treatment, this doesn't matter.
After heat treatment, you need to keep the temperature below 180 degree celsius, which is the the tempering temperature for steel. Coincidentally, this is also the temperature where steel oxidation makes pretty colors, with straw yellow being the color at ~200 celsius, and blue around 300 celsius.

The general rule of thumb is that if you see colors appear, you've ruined the temper and you either need to scrap the blade or re- heattreat it.

Steel heat up as ou abrade it. But when the steel is soft and the belts fresh, the hot steel gets removed before the heat can spread much. Hardened steel otoh heats up as well, but does not abrade as much, so heat can spread. This is why you have to run the belt at low speed for hardened steel, and regularly dunk the piece in cold water.

Originally Posted by Bruno

Yes. During the rough grinding stage, before heat treatment, this doesn't matter.
After heat treatment, you need to keep the temperature below 180 degree celsius, which is the the tempering temperature for steel. Coincidentally, this is also the temperature where steel oxidation makes pretty colors, with straw yellow being the color at ~200 celsius, and blue around 300 celsius.

The general rule of thumb is that if you see colors appear, you've ruined the temper and you either need to scrap the blade or re- heattreat it.

Steel heat up as ou abrade it. But when the steel is soft and the belts fresh, the hot steel gets removed before the heat can spread much. Hardened steel otoh heats up as well, but does not abrade as much, so heat can spread. This is why you have to run the belt at low speed for hardened steel, and regularly dunk the piece in cold water.

Thanks so much for all the help Bruno! That last post answered alot of things I had been wondering about.

It's always a good idea to grind with bare hands, for two reasons, one gloves and power tools are a dangerous combination, and two when it gets hot, you know it! Normally after heat treat and on a razor one or two passes it's too hot to move on and needs dunked in water. This way you shouldn't even come close to overheating it. Also another tip, when you get the edge to the point were it starts getting thin be very careful not to tilt the edge into the belt. At best you'll ruin your nice even edge, at worst you'll ruin a belt and have a razor flying around your shop.

Originally Posted by wynndow

Normally after heat treat and on a razor one or two passes it's too hot to move on and needs dunked in water. This way you shouldn't even come close to overheating it.

One or two passes, like the length of the blade being ground? And awesome I will be dunking the blade alot more than I had before, thanks! Also is there a width of the edge you leave before you heat treat it? I have watched several videos and they indicate basically I need enough so that if the blade warps in heat treatment I can grind down to a straight edge, but I havnt seen anyone list a ballpark width. With these I was kinda just guessing based on what I saw Lewis do.

And thanks for the tip on not tilting into the belt haha, that would be awful specially since its not my shop im using!

Yes the length of the blade, usually Ill start at the tang end move toward the tip and back in one motion then dunk. Like mentioned before, prior to HT you can grind on it till you can't hold onto it. But after HT the very thin areas will heat up much quicker then the spot your holding it so frequent dunks are best to be cautious.

And you have the right idea with the blade thickness, and honestly it's up to you personally I know guys that grind full stock after HT and I know guys that will take it down to 1/32 of an inch or less. Personally when I'm HTing a blade that gets quenched in a medium (like oil) I like to leave a little more (around 1/16 or more) just because it's a little more of a violent process as far as the steel is concerned compared to air or plate quenching (which is used on stainless type steels).

And lewis has some good videos I especially about taking it to the DMT then back to the grinder to make sure everything is parallel.

And I've hit the edge on the sander before and nothing crazy happens most of the time, just my stomach sinks before I look at the edge hoping I didn't just create alot more work for myself.