Can I lap a plane sole on a diamond lapping plate?

[Joe Beaulieu]

I bought a DMT DIA-FLAT Lapping Plate a month or so ago. I got it to flatten my stones, and I can say it does a much quicker job than anything else I have used to flatten my Shapton ceramics. Very quick and fantastic!
I have a Lie-Nielsen #41/2 Smoother that somehow got a nasty set of grooves or defined scratches on the sole. I mist have hit something buried in a board. I need to re-flatten the sole, but I am concerned that the diamond plate may make a scratched out mess of it. Should I stick to the sandpaper on the granite plate method? I can see the sole on that plane getting much worse if I run it across the diamond plate.

Any ideas?

Thanks in advance for any help!

Joe

[Nelson Howe]

I did it once. It worked great on the plane. However, the diamond plate was useless afterwards. I stick to sandpaper now. Diamond plates are expensive.

Nelson

[David Turner]

I would call Lie Nielsen's Customer Service and explain the grooved bottom to them.

Ask how they suggest removal. At best you will be able to send it back for repair. At worse, they will give you the proper method of repair.

David Turner
Plymouth, MI.

[Allan Speers]

As it happens, I talked to a DMT tech today about this very topic.

While I'm not 100% convinced about her response, since DMT has recommended NOT doing this is some of their advertising, and doesn't even list any metals in the application document, here's what she said:

Yes, it is completely safe and will not damage the diamonds in any way. However, when flattening any metal, one has to be more vigilant about keeping the plate clean, since metal fines have more of a tendency to clog the plate than waterstone fines. While the DIA-FLAT plates have a "polkadot" pattern which leaves lots of area for the swarth to go (as opposed to their "DIA-SHARP" plates) it's still a problem with metal. She recommends lapping metal underwater or at least under running water, and also to scrub a lot with Comet and a nylon brush.

What bugs me is that she didn't mention anything about the "hardcoat" technology. - By the time I realized this, it was too late to call back. DMT uses this coating specifically to protect the diamonds, and specifically for use with water & oil stones. I think it may be that this coating can get damaged by metals, and that could be why metals are not listed in the "application" doc. Maybe the woman I spoke to (who seemed otherwise VERY knowledgable) didn't know this.

Or maybe she is correct.
----------------------------

Other stuff to know:

1: The DIA-FLAT lapping plate comes in TWO grits: (mesh is the same as grit, only more carefully screened)

120 mesh (grit) - equals 120 micron. - This is called the “DIA-FLAT” plate.
160 mesh (grit) - equals 95 micron. - This is called the “DIA-FLAT 95” plate.

- The latter is a special order from DMT, so probably hard to find. If using the 120 mesh on fine stones like an 8K, it's important to rub very lightly. Evidently there's a significant difference in the 160 mesh, which is surprising.



2: Both DIA-FLAT plates are 4" X 10". For some reason, Amazon.com shows it as 5" X 14" ! There is no such animal.

[Allan Speers]

I did it once. It worked great on the plane. However, the diamond plate was useless afterwards. I stick to sandpaper now. Diamond plates are expensive.

Nelson

Was that with a DMT, or a less expensive plate? DMT's cost more for a reason.

[Derek Cohen]

Regardless of the durability of the diamonds, I would not be confident that the plate is flat enough. Also, a short diamond stone will be vulnerable to rocking the plane. Use a long length of sandpaper instead - cheaper and easier to ensure flatness.

Regards from Perth

Derek

[Mike Brady]

I have no idea if this axiom is true:

The harder the metal, the more effective at honing the diamond plate will be, and the longer it will last. This is for the same reasons as stated above: less clogging of the abrasive medium.

My personal feeling is that diamond plates are very expensive for the relatively short life they have. I am trying a Dia-Flat for stone flattening right now, and if it doesn't deliver as advertised, I am done with diamond plates.

[Allan Speers]

Regardless of the durability of the diamonds, I would not be confident that the plate is flat enough. Also, a short diamond stone will be vulnerable to rocking the plane. Use a long length of sandpaper instead - cheaper and easier to ensure flatness.

A good point. Especially considering that hand planes don't have to be "machinist" flat.


The reason I called today was not regarding plane soles, but that I'm looking for an easier way to flatten old blades and chisels. I realize you can just flatten a small area, or use a slight back-bevel, but I really prefer to get them dead-flat when possible.

[Joe Beaulieu]

Allan

Wow - that was impressive!! Can I expect this same level of support in the future? What a forum! :-)

I have a bad feeling regardless of what the nice lady at DMT says. I think it will scratch up the plane AND degrade the lapping plate - a "lose - lose" if you will. I will leave my nice soft ceramic stones to the lapping plate and stick with the sandpaper and granite plate. Its slower, but its so much more annoying I don't notice the slowness.

Thank you all for your help. I am pretty new to this board and I am loving it so far. Group hug! Ok - never mind that. But thanks all the same.

Joe

[Scott DelPorte]

Hi Joe,
Let me give another idea for you to consider. If the scratches aren't very deep or numerous enough to cause any part of the sole to not lay flat on the board, I might be inclined to just use a little very fine sanding to make sure there were no burrs, and then just leave it as it is. It might just be cosmetic. I could see someone wanting to clean it up even if its cosmetic, but the scratches may have no impact on your ability to smooth boards with that plane. Just a thought.

Scott

[ian maybury]

Another here Joe that's wary of diamond plates so far as flatness is concerned. Some examples seem to be very good (i've had good luck with Atoma for stone flattening), but ultimately a plastic or aluminium plate base isn't the most stable there is. Not sure how you would keep a sole flat without access to a reference surface if removing any significant amount of metal that way too. It seems likely to turn out to be long and very slow job anyway if the scratches have any depth...

[Robert Engel]

Joe - Before you do anything to the plane definitely call LN just to see what they say.

[Allan Speers]

I have to admit, having re-read the OP's post more carefully, I don't much like the idea of lapping away deep scratches. That will open up the mouth too much.

Best to leave them alone, or if they really bug you, fill them with JB weld then do a very light sanding.

[Mike Cutler]

I bought a DMT DIA-FLAT Lapping Plate a month or so ago. I got it to flatten my stones, and I can say it does a much quicker job than anything else I have used to flatten my Shapton ceramics. Very quick and fantastic!
I have a Lie-Nielsen #41/2 Smoother that somehow got a nasty set of grooves or defined scratches on the sole. I mist have hit something buried in a board. I need to re-flatten the sole, but I am concerned that the diamond plate may make a scratched out mess of it. Should I stick to the sandpaper on the granite plate method? I can see the sole on that plane getting much worse if I run it across the diamond plate.

Any ideas?

Thanks in advance for any help!

Joe

Joe

Am I missing something? While,the sole may have some deep scratches, they would have to be very deep to effect the operation of the plane. I have the LN 4-1/2, but I also have some "beaters" that have soles with scratches, but are flat, and they work fine. You can certainly flatten it to the level of the reference surface you pick. I use an old cast iron table wing that has been filled and flattened. I also,have som granite remnants I can use. You can start with sandpaper, nothing less than 400 grit, and work your way to 1200- 2000 grit, or use lapping compound.

None the less I personally would just contact the folks at LN. That's not quite a Stanley "beater" that you can toss, or keep for parts, if you mess it up.

[Mike Brady]

The sugestion to contact LN is a valid one. They will correct the sole for you and charge you minimally, if at all. The scratches are just cosmetic, by the way.