Do I need the 200mm Diamond wheel for my T4

[Segovia123]

I have owned the T4 for a few years now and too be honest it does not get used every week. Once my plane blades and chisels have a decent 25-degree angle I move to the Shapton Glass stones for the micro bevels. 

I struggle with getting blade backs honed to a mirror finish, I use wet and dry and then move to waterstones. But never manage to get a good polish, mainly because I get bored and settle for a happy medium. 

Would the introduction of a 600 grit diamond wheel help me get my backs polished, I tried it on the stone once but never felt comfortable using the side of the stone. 

How does the 600grit compare to the standard stone ?   
       

[Ken S]

Have you tried using the David Charlesworth ruler trick? It is very fast and effective for plane backs.

Ken

[John Hancock Sr]

I would not use the Tormek for the backs. I think the trick is to start on a coarse enough stone. I just got a new old Stanley #5 and the edge was pretty beaten up. I started on the back first with a Shapton 350 and had it mirror smooth to the edge up to 5,000 in no time. I only made sure that the first few mm from the edge was polished. Anything more is a waste of time. As you continue to sharpen always start on the back and over time you will get it more and more flat.

I never had cause to use the ruler trick myself but if it is taking too long to get it polished along the back of the edge then that will help. Don't do that with your chisels though. They really do have to be dead flat along the back.

[Ken S]

A couple thoughts on chisel backs:

In an ideal world, chisel backs should be flat. However, in the real world, as long as the back does not have a belly (protrudes convexly), a little concavity is OK. Although not always possible or practical, the best defense against either of these conditions is to purchase premium chisels.

My other thought is to look at the work the individual chisel will be doing. Precision joinery should have highly tuned tools. Rough work is not so picky.

Ken

[John Hancock Sr]

a little concavity is OK

May I offer an alternate opinion. Whilst that may be true for things such as mortice chisels there may be issues with things such as paring. If you are trying to get tenon shoulders flat for instance any irregularity on the back may result in uneven surfaces.

You reallu only need to flatten them fully once and any freshen up should be pretty quick.

[tgbto]

And as far as grits go, 600 will *not* get you a polished surface. Moreover, if you don't do it very often, the side of your diamond stone will stay for a long time in the "break-in period", and you'll get a lot of scratch marks. Even the DE-200 will not get you a polished surface, rather a hazy finish.