How do I lubricate and clean Diamond Sharpening Stones?

[D_W]

Not the files, but sharp corner scrapers. Files run just askew will go right past the mouth with only a little care toward not allowing them to cut slightly deeper around the mouth as their contact pad changes (that would probably be lapped out, anyway).

Scrapers on the other hand (think like a chisel with a 90 degree edge on the front but with the edge radiused a little) put a single point of contact and scrape the cast off - when they trip off of an edge into another one, they can chip it.

I've never had a fatal issue with a file, though - just another reason that I like it (it's faster than scraping, too. Only danger with a file is pinning, and that's just a finish issue (cast doesn't hold together that well so pinning should be minimal). Best remedy for pinning in actual large draw filing use is to discard the rules of "never pull a file backwards" and pull the file backwards every several strokes. It does wear a file slightly more quickly, but you'd have to value your time at about 50 cents an hour to make economic sense of stopping and carding out the pinning when a light back pass every several clears the teeth. Actually, it's probably negative value on time to not do it as not having to file out an area that was scratched deeply by a pinned bit of metal waste is a huge time saver.

 

[bentontool]

WD 40 is my go-to fluid for diamond stones. Works great IMO...

 

[steve355]

For what it’s worth, and maybe interest …. I’ve done a fair bit of scraping to get things “bonkers flat” as an earlier poster put it. It is indeed the holy grail of flatness. I’ve never done it on a plane sole, no reason it can’t be done but it isn’t necessary. Scraping starts where lapping stops. Generally, for plane soles I have a 0.0015” feeler gauge I use with an engineering rule. That’s plenty flat enough. That’s where scraping would start if you so desired.

For lapping plane soles flat it’s important to keep going with sanding on the heavier grits until there really is no high spots left. It’s very tempting to go to a finer grit early in my experience. Be aggressive. I have used a belt sander held upside down in a vice in the past on smaller planes. Seemed to work, but don’t blame me if you wreck your plane!

On scraping, a couple of pics below, the first of a surface grinder work table and a HSS scraper. You can see the blue marks on the table - that’s the kind of pattern you’d expect when a blued surface is on its way to being “flat”.

The second pic is of the ways on the bottom of the table. The numbers on the strips indicate “tenths” - ten-thousandths (0.0001) of an inch. The DTI is being used to measure if the two surfaces are co-planar. They need to be flat to a couple of tenths, co-planar to the same degree of accuracy, and also co-planar with the top (other side) of the table, which is resting on the granite surface plate (flat to c. 0.00001”).

Once you’ve done this kind of work, a plane sole being flat to a couple of thou seems like not such a big deal

By the way, I used to clean my diamond plates by putting them in the dishwasher. Was that bad?

 

[pgrbff]

WD 40 is my go-to fluid for diamond stones. Works great IMO...

oil not recommended on DMT, only water

 

[bentontool]

oil not recommended on DMT, only water

Thanks for the info. Do you have any idea why? I have seen no degradation of my stones.
I have had many of them, from (pretty-much) since they have been in business. My first (ex-coarse) 12" stone was dished in the center by 5 or 6 thou (if memory serves) and they replaced it.
Again, thanks.

 

[pgrbff]

I wouldn't normally buy DMT because I have never had a flat one but recently saw a large coarse and extra coarse on Amazon for $35 so I bought it. I don't know why but that is what the instructions say.

 

[bentontool]

I suspect that a generally available light machine oil may be too viscous to work properly, but the WD40 is so thin, that it seems to do the job well, and protect (to some small extent) from rust. I remember reading something about delamination of the nickle binder used to hold the diamond particles, but I do not recall the specifics. I have not seen that issue (yet?).

 

[bentontool]

oil not recommended on DMT, only water

From the DMT website:

• I know it says to use the sharpener dry or with water, but can I use oil anyway? Can I store my DMT stone in kerosene?​

  
  DMT recommends you use DMT products dry or with water only. Although mineral oil or WD40 will not harm the DMT products, they can impede sharpening if used in excess and can damage the sharpener overtime if not properly cleaned/removed from the sharpener. DMT recommends that you always wipe your Diamond Sharpeners clean and store dry after use. Put away your benchstones dry and store in a dry area. Use leafing (paper towels, cloth, plastic storage bag) in between your bench stones to prevent abrasive sides from rubbing.