[Q] DMT extra extra coarse diamond plate

[Fromey]

I'm sick of flattening plane blades! :? I just tried to speed it up with some 100 micron scary sharp paper glued onto MDF, but it seems to have ridden up and resulted in an even more undulated back that I started with #-o

I'm seriously considering buying a DMT extra extra coarse (120 micron) Dia Sharp diamond plate. I figure it will flatten plane irons and chisels properly (and hopefully easily), establish primary bevels and cambers, and flatten water stones. It should last a lifetime.

However, I'm not sure if diamond plates can flatten/dress oil stones (I have three Norton India stones (coarse, medium and fine)). If they can, it would add extra value and help justify the initial outlay.

Does anyone have an answer?

Thanks in advance.

 

[Corneel]

Personally I don't like diamond plates, nor sandpaper in fact. They start out wonderfully fast but quickly settle into mediocre performance. The nice thing with waterstones is that they always perform at peak performance, until worn thin.

There are now some nice coarse grid waterstones, Sigma, Bester, that are quite hard and don't dish so quickly. Still, flattening vintage chisel backs is still hard work, even when you only flatten a short patch behind the edge. I find nothing quite beats NEW 80 grit sandpaper glued to thick glass. It helps to use a stick on top of the chisel to exert extra pressure. After that it is the 400 Bester stone, then 1000, 4000, 8000 stones.

For flattenig waterstones the diamond plate is excelent. I have seem a video from Larry Williams (Old street tools) who uses a diamond plate to keep his oilstones flat.

 

[matthewwh]

No point in flattening plane irons, just use the ruler trick or pop the sharp end in a vice and donk the top gently with a hammer until the underside of the cutting edge touches first.

For chisel backs (and primary bevel work if you use secondarys) the xxc is excellent, working across the width of the stone will give a slight concavity from which you can approach flat with your finer abrasives.

 

[dunbarhamlin]

I have a xxc stone, it is good for refreshing stones but really dislike it for prepping plane irons and chisels. The scratches it leaves are very deep. I prefer using my wet grinder to produce a slight longitudinal concavity and then just use a 1000 grit water stone or coarse oil stone.

 

[Peter Sefton]

Hi Froomey
We have been using some industrial PSA backed Scary Sharp in the workshop which we find is the best thing for initial flattening of blades (starting with 80 micron and working down to as low as you want to go) always on float glass or granite. I prefer to flatten all my plane blades - Veritas will only need final polishing but most other makes need varying degrees of work but for me the hard work is worth it, in the long run. Send me a PM with your details and I will post some samples out for you to play with.

http://peterseftontoolshop.com/epages/e ... MSCARY-80X

Cheers Peter

 

[Phil Pascoe]

Matthew -workshop heaven - says not to bother flattening plane irons. Oh excrement, here we go again.

 

[Fromey]

Thanks for the feedback everyone.

From what I've now read on other, largely US, forums, it looks like the DMT plates are not particularly flat (granted the posts about this were in 2009 and a lot may have changed) and that the xx coarse leaves deep scratches (RE your point dunbarhamlin). Thus, I now wonder about their duo-sharp 60/45 micron plates as an alternative. The 120 plate simply as a stone flattener seems a bit excessive.

Corneel, I'm also seeing a lot about coarse waterstones on forums. I will investigate further. Thanks for the tip on brands. I take it one can flatten coarse waterstones using wet & dry paper on glass? The coarsest I have is 120 grit, so I will invest in some 80 grit. There are some good deals online.

Peter, thank you for the very generous offer. In fact, I already have some sheets of PSA-backed extra thick scary sharp in very coarse grits. I like them, but they loose their bite very quickly for something like flattening plane backs. In fact, I started out using a 100 micron sheet, but when it started taking too long I stupidly switched to my old 100 micron sheet I'd stuck to some MDF. The adhesion obviously wasn't as good as the PSA-backed on glass, so it ended up dubbing down all my edges. I ended up in a worse state than I started with!

Matthew, I really respect your opinions and understand it's only the very end that needs to be flat. But banging it with a hammer!? (hammer) :shock: I'm not sure if you're pulling my leg or not. Sounds like one for demonstrating with a video if you ask me.

The search continues....

 

[Phil Pascoe]

I flatten my waterstones on a concrete coping stone on the garden wall. Undoubtedly a lot of people will sat I mustn't/shouldn't, but it works perfectly well.