Thread: Lapping Methods

Originally Posted by Howard

For precision metal work, I have a steel plate made for the purpose and it uses a thixotropic grease of the Clover brand. The plate is HEAVY and the base is cast so there's minimal (< .00001") flex. The lapping surface is cross hatched to prevent any buildup of lapping compound which would throw off the process. If the plate is kept at consistent ambient temperature, you can get repeatable flatness to spec.

For razors I use the DGLP on my Shapton glass stones supported flat by the stone holder and in the pond with its specially treated surface (very very flat and no slippage) on top of a granite surface plate flat to .0001" across the whole surface. This setup gets me consistent and repeatable results.

Howard, you take all the fun out of this for people, they're gonna read this and get scared off. I know your from Mass, Have you been hanging around MIT....We are talking razors and hones, not stuff going up on the Space Shuttle? I bet stuff on the Space Shuttle isn't as exact as the edge off one of Howard's Razor's. Howard, are your surfaces flat as a "Gage Block".
You know what they are, right?

Barber's have been doing this for over 100 years, I think they got it right, and doubt they had all that fancy stuff, This is shaving, Let's not make it Physics 101. If it works for you, great. People shouldn't think they need all that to get a good Shave Ready blade and good flat hone. As the other Gentleman said, "Being a dealer has it's andvantages"...

I'm no gentleman, but I seriously do still want to know how often Howard laps.

What are the tell-tale signs that it is time to lap? I think it is an important question.

As a rule, I lap a stone after each thing I sharpen, and if I am sharpening a bunch of my reed knives, I rotate the stone after one knife, then lap after the second. I do all of my real work on the #220 or #320, which gets rotated with each side of the blade, then lapped to be fresh for the next thing.

To come to Howard's defense, I wanted precision when I first got into sharpening about 8 years ago. It makes a lot of sense, really. An extremely flat stone + an extremely straight, flat bevel = sharp. I was all into the guides while I was still learning the basics. They really helped me on the road to freehand sharpening, which is much less about precision and more about consistency. But there is equipment degradation as well, which is what put me off the high precision track. Freehand gives the sharpener much more control and feedback. Straight razors don't have that issue as much, since they are usually flat on a stone, though.

As a professional sharpener of things other than straight razors myself, I really don't think Howard is off his rocker, a little extreme, perhaps, but when you have to satisfy paying customers with your sharpening, a reputation can easily be tarnished or ruined by an unsatisfied customer. Precision is a good thing that really speeds up the process while minimizing some of the variables.

Tom, I do a light lapping of my GlassStones with the
DGLP immediately before sharpening, each time. I
think that's a good way to keep the stones flat enough,
and they're probably most likely to lose their flatness
during the period between sharpening sessions.

- Scott

Originally Posted by jendeindustries

I'm no gentleman, but I seriously do still want to know how often Howard laps.

What are the tell-tale signs that it is time to lap? I think it is an important question.

As a rule, I lap a stone after each thing I sharpen, and if I am sharpening a bunch of my reed knives, I rotate the stone after one knife, then lap after the second. I do all of my real work on the #220 or #320, which gets rotated with each side of the blade, then lapped to be fresh for the next thing.

To come to Howard's defense, I wanted precision when I first got into sharpening about 8 years ago. It makes a lot of sense, really. An extremely flat stone + an extremely straight, flat bevel = sharp. I was all into the guides while I was still learning the basics. They really helped me on the road to freehand sharpening, which is much less about precision and more about consistency. But there is equipment degradation as well, which is what put me off the high precision track. Freehand gives the sharpener much more control and feedback. Straight razors don't have that issue as much, since they are usually flat on a stone, though.

As a professional sharpener of things other than straight razors myself, I really don't think Howard is off his rocker, a little extreme, perhaps, but when you have to satisfy paying customers with your sharpening, a reputation can easily be tarnished or ruined by an unsatisfied customer. Precision is a good thing that really speeds up the process while minimizing some of the variables.

Agreed, I even went to school for machining, milling and drilling where being precise is needed. That's where I first saw a set of gage blocks. So, flat, that when pressed together, no air can fit inbetween, it's pressed out, and the gage blocks stick togehter....Now, that's flat...when your talking .000001, is that really needed for razors, I don't think so, but it's nice.

Tom,
Ha! You're absolutely right . . . there are few people I can talk with who don't glaze over after the first 30 seconds of hone and honing talk. It's one reason Harrelson and I get along so well! For me honing is a separate activity that I do for the love of getting things really sharp, especially razors as it's such an extreme honing exercise. I've been making knives and other cutting implements for a long time and so much work goes into the correct steel choice and the heat treatment that it's a shame not to bring out all the potential the steel is capable of yielding. I actually keep a copy of the Metals Handbook, Vol 4 Heat Treating on my night stand. My wife thinks it's a sick thing. It all pays off though when a weird problem crops up and you sit there scratching your head. I find some razors only will sharpen with a backhone while most will sharpen well with a side hone. Why? We may never know but hopefully the store of knowledge will give some insights about how to make the sucker shave!

Howard,

I often dream about scratch marks. My wife says she'd rather I had an affair instead of thinking about sharpening all the time...

I use a double sided 400/1000 grit diamond plate. Bought it just for lapping, since it probably changes the grit over time.

Mac

ok i must be really cheap i just use a glass cutting board and 400/800/1500 grit paper seems to work well.

Not cheap - frugal.

If you are just touching up 1 or 2 of your personal straight razors, you are not going to need such heavy duty equipment. And if it works for you and you are satisfied with the results, then it must be alright.

i only have one barber hone right now so i i go into deeper then we will see lol. but it seems that alot of folks also use heavy glass i may go that route when i get serious lol