I'm going to be very presumptuous and say the diamond plates you have already will do what you need.craigsalisbury":295tay1a said:i need to get some decent stones, any recommendations that arent £120 each?
With double-iron planes you don't need to get the edge sharp like a razor for the plane to work well. You can easily plane softwoods using an iron that was sharpened on only a medium-fine oilstone, as long as you've raised a burr and successfully removed it all. The usual 'fine' diamond plates are approximately equivalent to those old oilstones so practice with what you have until the plane will take good shavings from some scraps of pine.
For when you do need a more refined edge you can do a lot by stropping, and most people have suitable scraps lying about that they can make a strop for nothing. Strops can be used dry or loaded with any number of very inexpensive compounds or metal polishes depending on how aggressively you want them to work.