Cheap, flat diamond plates - DIY (partly)

[Alistair Witt]

Hi, (first post)


I thought I’d share a cheap and flat diamond sharpening plate I put together, with a replaceable top; it may come in handy for someone else.


I acquired some plane blades with the bevel angle way off, so I was looking for a very coarse diamond plate to quickly get the bevel right. Unfortunately, they’re around $100 in my area for one large enough to handle large plane blades using a honing guide, so I looked for a cheaper option.


I found some cheap diamond plates on eBay for $8 each which come in grits ranging from 150 to 3000 mesh. However, these are just some thin (1mm) sheet steel with diamond coating on one side, and are therefore not stable or flat. My solution was to grab some 75x10mm (3x3/8”) mild (hot rolled) steel and cut it into lengths to suit ($20 got me four pieces and some left over). I then took these to a local machine shop and had them mill one face on each piece flat (they charged $15 each). Next, I glued the diamond plates to the top of the machined steel surface and now have four diamond sharpening plates with replaceable tops (of whatever grit I choose) for a similar price as one plate from the shops. It should also be quite flat. Photo attached.


A final detail: I drilled and tapped an M4 hole near one corner on each, so that I can thread a bolt through and lift the corner of the diamond plate in order to help remove it when needed.


Another thought was to use some machined blocks of aluminium and glue in a handful of rare earth magnets in the top to make it even quicker to change. Might try this someday.


Hope this is useful for someone!


Cheers,


Alistair

IMG_3943.jpg

[Mike Henderson]

Neat idea. Thanks for sharing. And welcome to the Creek.

Mike

[Bill Dufour]

You could probably buy a granite surface plate for that cost. A used one is plenty good enough for woodworking.

[Alistair Witt]

You could probably buy a granite surface plate for that cost. A used one is plenty good enough for woodworking.

Fair point, and I like your idea. However, granite surface plates in Australia (where I live) are very expensive by comparison to US prices, and the second hand market for such things is very much smaller too. I often look with envy at the pricing and availability on US websites.

Alistair

[Derek Cohen]

I have those diamond plates in 800/1000/3000 off eBay. They form part of my travel sharpening kit. They are epoxied to UHMW sheets. They are not stiff like steel, but are stiff enough when placed on a bench top, and light and rust free. I do not plan to lap blade backs with them.





I am not sure how long they will last, but they are doing a decent job right now.

Regards from Perth

Derek

[Bill Dufour]

Traditional source of flat enough material for such work is glass sheet. I have a piece of 3/4" thick glass which I use when needed. At that thickness it is not likely to break. It may chip if abused.
Bill D.

[Alistair Witt]

Fantastic! I suppose a useful takeaway message is that there are several cheap and effective options for getting diamond plates, and it doesn’t have to be prohibitively expensive.

Cheers,

Alistair

[Derek Cohen]

Traditional source of flat enough material for such work is glass sheet. I have a piece of 3/4" thick glass which I use when needed. At that thickness it is not likely to break. It may chip if abused.
Bill D.

Many years ago, I epoxied all my Shaptons to glass. This has aided in keeping them flat and using them as long as possible. I turned to UHMW instead for the diamond plates as they are for travelling. Glass would make a good substrate for the diamond plates if used in the shop.


Regards from Perth

Derek

[John K Jordan]

Fantastic! I suppose a useful takeaway message is that there are several cheap and effective options for getting diamond plates, and it doesn’t have to be prohibitively expensive.

I don't know how much steel plate diamond hones usually cost. I bought some with CBN from WoodTurners Wonders a couple of years ago 2-sided with a different grit on each side (on 2-3/4x8" 1/4" thick steel plates) but then I ordered some coated instead with diamond at the same price I think. Since the value of CBN is in it's ability to hold up under intense heat from high-speed grinding, I didn't see any reason to not use diamond for sharpening by hand.

I bought three plates for six grits from 180 to 1200, about $50 each or $25 per grit. They work well, especially for sharpening ceramic cutters for my llama shearing. Diamond works a lot better than CBN on ceramic.

JKJ

[Richard Jones]

Alistair,

I know you guys have Corian down there. Perhaps a visit to a kitchen cabinet shop would yield some offcuts.

[Bill Dufour]

Would granite or marble floor tiles be flat enough to be useful? Theoretically you can hand scrape any stone or metal to get it super flat. That is how a precision straight edge or surface plate is finished after grinding. Of course that means you have to buy more tools and inspection gear.
Bill D.