So I Bought This Yesterday

Trout Hound · Dec 30, 2014

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It's a concrete brick. It was $0.51, including tax, at the home center. It's 8x4", which means it's really 7.5x3.5". (I never knew that masonry dimensions were lies, just like lumber.) Anyway, I brought it home and gave it a try lapping the coarse side of my Crystolon stone, and it did a fantastic job! It clogged pretty quickly, since the grit size is actually pretty close to the stone, and it picked up a lot of oil, but I used all four of the long surfaces and got the job done. Next time I will start on the sides, since they are rougher and really get with the program, while the top and bottom are smoother and flatter, and better for final flattening. I'll throw in some dish soap to help with the oil next time as well.

That economy stone was glazed up pretty good before I started, and after three minutes on that brick, it was like new again. I used it to even up the angles on the pen blade of my new Case jackknife, and it went through that CV in no time!

I'll need to get a second one, to use in de-glazing the first. I figure if I use a little soapy water between them, and alternate multiple surfaces, I'll end up with everything reasonably flat. Plus, I can keep these right by my sharpening bench, and the Mrs. won't get hot about any unsightly lapping marks on the front walk. 😗

I think I'm probably gonna do this to my Crystolon pretty often just to keep it cutting fast. As cheap as it is, I don't care if I wear it out more quickly, and it works SO MUCH BETTER.

And no, I will not lap my waterstones on it, I promise. 😁

HeavyHanded · Dec 30, 2014

What do you use on the Norton when sharpening? Generally speaking, silicon carbide will break down and refresh itself as it goes, especially if used with oil. Should only need lapping if it becomes dished out.

Trout Hound · Dec 30, 2014

Well, I was using oil - first the Norton, and then USP mineral oil when that ran out. Maybe I was imagining things. I dunno.

Obsessed with Edges · Dec 30, 2014

I'm also wondering why the Norton 'Economy' stone is glazed (assuming that's the one you're referring to)? If it's one of the older Norton Economy stones, it might be in aluminum oxide, instead of SiC (Crystolon) abrasive. If so, those can glaze much more easily than the SiC stones, which stay much more consistent. Newer versions of the Norton Economy stone are SiC, and are darker in color, almost black, as compared to the greyer AlOx stones. There may still be some of the older versions in stores, if you bought yours recently. See the darker SiC stone in the pic below, in comparison to the other two grey stones in AlOx (the one marked '87933' is the older AlOx Economy stone):

All that said, the 'brick' as a lapping stone sounds like an interesting idea to try out. :thumbup:

David

Trout Hound · Dec 30, 2014

No, this is a new one. Like I said, it might not have been as bad as I first described. Isn't it true, though, with vitreous stones, that the abrasive breaks down faster than the bonding agent, and that lapping will expose fresh abrasive?

In any event, at least I have an easy way to lap it, whenever I need to.

Thanks guys!

Obsessed with Edges · Dec 30, 2014

Trout Hound said:
No, this is a new one. Like I said, it might not have been as bad as I first described. Isn't it true, though, with vitreous stones, that the abrasive breaks down faster than the bonding agent, and that lapping will expose fresh abrasive?

In any event, at least I have an easy way to lap it, whenever I need to.

Thanks guys!

Not sure if you caught my latest edit in my previous post. If you bought yours recently, it's still possible that some of the older AlOx Economy stones are still in stores. At any rate, the new SiC versions of this stone seem much more consistent in their grinding speed; the SiC grit will continually break loose and expose new, fresh grit. Older AlOx stones don't ordinarily shed grit as easily, so the grit at the surface can become much more worn (glazed) and slow down.

David

Trout Hound · Dec 30, 2014

Mine is definitely the darker color. I'm probably just impatient. 😁

Obsessed with Edges · Dec 30, 2014

Trout Hound said:
Mine is definitely the darker color. I'm probably just impatient. &#55357;&#56833;

What steels have you been sharpening on your Economy stone? Don't worry, I believe you, I'm just curious (

). Something like S30V or D2 and maybe 440C might go a bit slower (very likely), but the SiC versions will eat most anything else in carbon or mainstream stainless, and especially steels like 1095, CV or 420HC.

Not pickin' on you; I'm just somewhat intrigued and usually impressed by these SiC stones, and always interested in seeing or hearing about how effective they are on different steels. I'm going into town today, and will likely pick up another pocket-sized version of a SiC offering from Ace Hardware, in fact. That'll be my 4th...

David

Trout Hound · Dec 30, 2014

Stop! Hold the presses! I remember what I did now! After using that stone to do a pretty significant angle reduction on two Buck 420HC blades, I noticed it had dished slightly along the edge in a couple of places. I tried lapping it on the coarsest grit sandpaper I had, which was 80 grit AlOx, and I flushed it heavily afterwards, but I bet I still managed to clog it right up with the other abrasive. I had forgotten that I did that. THAT'S probably why it wasn't cutting as fast. User error. 💩