Lapping thread

[Rustynail]

What grit W/D sand paper would you use to lap the following stones? :

- shapton pro 1000
- washita
- soft ark
- hard ark
- shapton pro 8000
- ILR
- black convex ark

Thanks for your input.
Jon

 

[Darth Scandalous]

I've used 600 on my ILR and both 600 and 800 on my trans ark. Not sure I could tell a difference but *maybe* I liked the 800 better.

I don't own the same synths as you listed although I do have a Shapton pro 1.5k. I use a beat up 400 diamond plate for all my synths.

 

[Herrenberg]

You can go through a whole lot of sandpaper trying to lap a stone. Consider silicon carbide powder, wet, instead:

- It's cheap (amazon or Got Grit)
- The grit doesn't actually matter that much because it breaks down to a finer grit pretty quickly. Maybe for final lapping.

I've been using it on a granite tile, but someone here suggested a cheap stainless half-sheet pan on a concrete floor, because it's easier to apply a lot of pressure. I haven't tried that yet, but plan to, the next time I have to do serious lapping.

I do use diamonds on my Japanese synthetics, but if I ever had to lap an ark or a Spyderco ceramic or some other really tough stone, I'd definitely go with the SiC powder, out of fear of wearing out my plate.

 

[duke762]

You really need loose grit for initial lapping on the Arks. Give the softer ones a final dressing on 400grit W/D and the hard, a final dressing on 4- 600grit. Not a whole lot you can do with your convex Ark, dress it by hand with 600grt maybe? Personally I'd sell it and get one I could keep dressed flat. The 600 grit would work on the Shaptons also. ILR...can't say for sure 400 maybe? Gamma has some great lapping insights hidden away in a thread somewhere. I use his recommendations as gospel.

 

[Rustynail]

Thanks all for the advice. I like to buy local if possible but i guess ill have to make an online order for some sic.

Im not selling my ark, BUT i do want to flatten the backside so i can be a 2 in 1 stone. The metal tray and sic sound like the way to go for that job.

What grit sic do i need to buy?

 

[duke762]

Depending on how far out of whack the backside is.

If it's ugly and not flat, you'll need more aggression. Let's say 120 grit. Really bad? Use a lower grit. I've gone as far as silica sand on concrete to get a really wonky stone in shape.

Since it's a black, and if it looks half way descent, 240 or 220, what ever it is, grit may be a good starting point. Clean the stone and check for flatness periodically before moving on.

With a Black Ark I go to 400 and then 600 before switching over to 600 W/D for final flattening.

A couple things to keep in mind...

Loose Sic doesn't do a lot cutting of the Ark at lower grits. It's more of a micro pitting action caused by the grit rolling around and eroding the surface.

Sic breaks down pretty fast, keep a watch on the feel of the grit.

Fixed grit, high quality wet/dry to finish. Loose grit will not get the stone as flat as W/D on a flat surface. I do mine at 600 girt and religiously redress the hone the minute it even threatens to glaze, run in, or burnish.

Feel free to experiment, that's half the fun. YMMV quite a bit.

 

[H Brad Boonshaft]

You can flatten the Shapton’s and ILR with 220, but a diamond plate is cleaner and easier. You can buy a good 400-1000 grit diamond plate for $30 from Chef Knives to Go.

You will not lap Arks with Wet and Dry, or a Diamond plate, loose Silicone Carbide will get it done quickly, 60 grit. You can buy a progression 60-500 for $15 from Got Grit .com.

The dollar store steel cookie sheet is the way to go. An Ark will trash a Diamond Plate in short order, rip the diamonds out. You can finish an Ark with 600 and up, once the stone is flattened with loose Silicone Carbide

 

[TexNat]

For my Dan’s black and translucent Arks, the Atoma plates with mineral oil make quick work. Washing the plates and stones is required when the slurry builds up. The 140 flattens, the rest just refine the finish. For the final polishing, I started using a Kitayama 8,000, which came in a package deal and which I never really liked.

It was sitting on the shelf unused and I thought, what the heck, see what happens. Turns out the 8,000 grit waterstone noticeably improved the finish on the Dan’s trans Ark. My Dan’s translucent surface ended up much finer than before. The surface still cuts a wee bit since it is not glazed like the grind it with chisel method, which impairs the surface’s cutting ability in my view. Just my opinion, if others like it, great go with what works for you. I spent a solid 30 minutes on the first effort and still hit it for 10 minutes now and then.

To finish on the polished side of the Ark, I start with mineral oil, shaving the oil off, wiping it on a dry cotton cloth, until it is just a thin sheen.

Then take 20 or so laps on the sheen. Then wash the stone with dish soap and water. Rinse thoroughly. Finish with another very light 20 laps on just water.

Then take just four or five super light passes on a flat slick Tony Miller strop. Done.

As a reference point, the Dan’s Ark polished side now produces a sharper and more comfortable edge than my Suehiro Gokumyo 20,000- noticeably sharper and more comfortable too.