Flattening a New Norton 4k/8k?

I got a new Norton 4000/8000 stone for Christmas. This is my first big-boy hone (I've been getting along thus far with a Col.Conk box-set hone), and I've got some questions about commissioning it for its first use.
As I was led to expect, the stone was NOT ready for use out-of-the-box. My first attempt at flattening it yielded mixed results, so now I'm turning to y'all's collective wisdom to set me on the right course.

For my first stab at flattening, I used the sandpaper and pencil-grid method. I started with Norton 400 grit wet/dry sandpaper laid over a marble floor tile. I rubbed the face on the sandpaper in figure-eights until a thick yellow slurry developed and the sandpaper seemed completely clogged. Then I changed it for a fresh sheet of 400 grit. The first result was that the grid in the middle wore off before the corners. I thought this was promising, but three sheets and a lot of elbow grease later, the surface was noticeably smoother in the middle, but the edges are still rough.

What's my problem? The most obvious possibility to me is that 400 grit was too high to start with. I was afraid of scarring the surface with anything lower, but if that's what is called for, I'll head back to the hardware store and do it. I've got five sheets of 600 grit waiting in the wings, but I figured I'd just be wasting it if I moved up before the whole surface was 400-grit smooth.
How should I proceed from here? Move up in grit? Move down? Yet more time on 400 grit? Use the slurry (I still have used sheets with the dried slurry)? Sinking the cash for a Norton flattening stone is an option, too, if that will really give me the best results.

Thanks in advance, with more questions sure to come . . .
Alexander

How ya doing, havent seen you in a while? I would try the lower grits. Re- grid it and try again. Are you doing this under running water, it may help to keep the paper from clogging. Thats the way I do it, except I have the Norton flatner.

i really don't know how flat is your marble floor?what you have done is right approach.you should be ok,remember put sandpaper flat surface -most people uses glasses and it does work.Your last choose could be norton flatten stone will do the job.remember you will need to at least 1000 grit sandpeper end of the lapping.frequently wash sandpaper and continue use 400 don't push too hard sandpaper should do the job.Pencil marks will show you where is the problem.hope this help.

My Norton required a ton of lapping on the 4K side to put it into acceptable condition for honing razors. It wasn't so much a flatness issue as it was a surface condition issue. The stone had a very granular feel to its surface until I had lapped off about an 1/8th of an inch. If yours is the same way you can plan on making a bulk purchase of sandpaper. You might be better off all the way around if you popped for the flattening stone or a DMT 8C (both are 325 grit btw, as is the Shapton GDLP).

Don't forget to relieve the edges.

i always soak the paper also, i'm not sure if you are doing this but it may work better for you. about 10 mins is what i do. also, the first lapping is usually the worst so don't be afraid that it will be like that everytime. i used 320, then 600, then 1000 for my first lap. now i just use either 1000 to 1500, whatever i have, and it works fine. another thing is to really clean the hone with a brush inbetween grits and sheets of paper so you don't get grit embedded in it.

good luck

My method is a little different than the ones stated above. I use Norton 3x sandpaper and use a 120 grit. I use light pressure and rinse the paper and stone often. I find that the Norton sandpaper deteriorates pretty quickly and I am left with a very smooth surface when finished.

But, as for your original question. You seem to be doing the right things to get your hone flat. Just keep going until it is flat.

I used to lap my 4k/8k with moistened 600 grit wet/dry sandpaper over a sheet of plate glass because I didn't want to spring for a flattening stone. I found that the slurry that would build up during lapping would erase a lot of the gridlines before the stone was truly flat. It wasn't until I finally bought a DMT8C that I realized how far from flat that my stone was. It wasn't too bad but there was certainly room for improvement.

Maybe going through a progression of grits as I've read that some others do will get you there but this is one area of straight shaving that I don't want to waste time in. I would rather spend my time refining my honing, stropping, and shaving techniques. I would urge you to buy a good flattening stone and be done with it.

I didn't realize the flattening stones had such low grit. If I go with the flattening-stone route, will I need to finish on high-grit sandpaper after every time I use the flattening stone?
Thanks,
Alexander

Quote:

---

Originally Posted by NeitherMightier

I didn't realize the flattening stones had such low grit. If I go with the flattening-stone route, will I need to finish on high-grit sandpaper after every time I use the flattening stone?
Thanks,
Alexander

---

I dont bother with lower grits after the flattening stone, I simply lap it under running water so that any residue is washed away.