A few belt grinder questions

[Torin]

Do many people here use the technique of covering your work with black sharpie before switching grits to make sure you get all of the deep scratches out before moving on to an even finer grit? I've started trying it, and it seems to be helpful. But I thought I'd check and see if I'm missing out on any downsides before I star laying in a bunch of new sharpies.

Also, speaking of grits, what are your favorite grit steps when trying to minimize grinder time? I'm current running 36/50 to start, then 100, 220, and 400. Are there better steps?

And how do you decide when your belts are too worn out to use anymore?

Thanks in advance!

[Rich Hale]

The grits you use are good ones however you have not said what materials you are grinding. And the quality of the belts is crucial. Ya buy junk ya get junk....I did a bp a few years back covering all the steps I use to complete a blade, when the bps return check it out. And I use a bright light to chack for scratches.

[Torin]

I'm grinding 15n20/1095 pattern welded material. The 50 grit belts I'm using are the yellow ones from K&G that you recommended to me. I'm also using the belts from industrialabrasives.com that JPH recommended to me. They aren't the greatest belts, but Jim said they have a good price/performance ratio. I'm using their plain aluminum oxide belts for my 36/100/220/400 grits.