Burning tips

[Bühlmann]

Aside from keeping the blade cool, are there any other tricks or techniques to help with tips eroding away when grinding bevels?

 

[polish avenger]

Fresh grinding belts. Light pressure.
Are you grinding pre or post heat treat?

 

[FredyCro]

There is also a trick that Don Nguyen uses which it to leave a small square at the end of the tip to act as a heat sink until you finish grinding. Then grind the square off once you are down to thickness.

Fresh belts, also lower grit produces less heat, so getting 90 percent of your final thickness with low grit.

 

[Bühlmann]

Fresh grinding belts. Light pressure.
Are you grinding pre or post heat treat?

Post HT.

 

[Bühlmann]

There is also a trick that Don Nguyen uses which it to leave a small square at the end of the tip to act as a heat sink until you finish grinding. Then grind the square off once you are down to thickness.

Fresh belts, also lower grit produces less heat, so getting 90 percent of your final thickness with low grit.

That's a good..."tip". I've thought about just making the blade 1/2" or so longer and then finishing to length once bevels are complete.

 

[Hubert S.]

That's a good..."tip". I've thought about just making the blade 1/2" or so longer and then finishing to length once bevels are complete.

Extra length is good, but also consider leaving the spine straight until after the bevels are ground, or leave a small square at the tip as Fredy suggested (I prefer to just leave the spine straight). The extra material makes it easier to hold and conducts some heat away. You have to be careful when profiling the spine and bringing the point down, it's also easy to overheat the tip. Dunk the tip often and use a mist coolant system if you have one. I profile the spine with the tip pointing down.

 

[HSC ///]

I prefer to keep the blade cool.... with water
you don't need a mist coolant system
you can simply use a squeeze bottle of water and douse the belt so its totally wet.

 

[ChristoDart]

All the above. I’ve started leaving some extra at the tip for support if using a jig and also to help with over heating.

https://imgur.com/a/GANzQK2

 

[Taz]

I leave extra at the tip when rough grinding as well. I hold a wet sponge to the belt briefly when running to wet down the belt. When I see the water drying on the belt, I dip and apply the sponge again. I want to get a mister set up since I do almost all of my grinding post HT.

 

[velegski]

Good ideas by all. Slower grinder speeds with fresh belts.

 

[Cushing H.]

I have found that when grinding, my original temptation was to draw the tip all the way across the belt. Since, i have been careful to stop the draw *just* when the tip comes even with the edge of the belt. Not a complete cure, but it helps.

Have not tried the extra square of material yet, but have several profiled blanks with that feature ready to be ground.

 

[Bühlmann]

What do you guys consider slow belt speeds? Say for 36 & 60 grit belts.

 

[Crag the Brewer]

Are certain steels giving you more grief than others?

Aside from fresh belts, straight, flat back spine early, water, no gloves, no jigs.

I also do some of my tip shaping with diamond files and aggressive stones.
It keeps me from getting Hot.

 

[Bühlmann]

Are certain steels giving you more grief than others?

Aside from fresh belts, straight, flat back spine early, water, no gloves, no jigs.

I also do some of my tip shaping with diamond files and aggressive stones.
It keeps me from getting Hot.

I’ve made shorter blades with 15n20 & 5160, which are the steels I have the most experience with so far. I’ve tried to not muddy my own waters with a bunch of different steels. Do they really grind differently (post HT)?

 

[velegski]

Belt speeds.
First let me qualify that I use VFD's on my grinders, and no mister''s on grinder and mostly lesser quality belts.
Second I'm a hobbiest, not a full time knife maker. Therefore I can take more time on the blade.
Since threading a blurb by MS Ed Caffrey I seldom run at full speed. For heavy grits I run about 75%, 120 grit at about 60%. 220 grit at about 40%, 320/400 at about 35% or slower.
Using slower speeds has equated to longer belt life, creates less heat on edges and allows more control in my grinds.

 

[REK Knives]

I grind with coolant being sprayed on the belt... Makes a HUGE difference

Another big help when it comes to tips is using a sharpie or dykem to see where your belt is hitting each pass