I too have ordered a set of similar cheap Chinese diamond plates off Ali Express.
They are about 5$ each, grits are available from 80 to 3000 (sadly I have no idea which standard)
They are 170 mm x 75 mm large and 1 mm thick.
I have ordered five plates (three 400, one 1500 and one 3000 grit) and all of them came near perfectly flat. There is however some slight roughness on the very edges of the plates.
I have glued them onto a plate of fiberboard with PVA glue as a temporary solution but it took such a hold I cannot remove them now. This is an issue since the board may warp from the moisture from the lubricant.
The plates were very sharp and effective when I started using them, taking steel off quickly with even light pressure, but the coating quickly started abrading off, losing effectiveness and cross-contamination became an issue: diamond particles from the coarser plates scratched the finer ones. I caught this quickly, wiping my edges diligently prevented further scratching and the scratches almost completely disappeared as the plates settled in.
After lapping the back faces of my tools flat (3 plane irons and 4 chisels only) the plates mostly settled in, lost no more of their abrading power and stopped releasing scratchy particles.
I have used them for about two months now and they seem to hold their power, which is good enough for honing razor sharp edges or fixing small fractures. They now require moderate pressure to work correctly, Paul’s technique works great here.
I seriously recommend them to anyone with a tight budget, especially to anyone considering the scary sharp system. Even if they keep dulling, they will likely be more cost effective, more accurate and require much less fuss than sandpaper.
- This reply was modified 5 years, 2 months ago by Szoltomi.
Curious to know how the diamond plates are holding up. Do you have a link or name of the company that sold you these on aliexpress?