Flattening the backs of chisels and plane irons
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Hi All,
Sorry if this is a dumb question, or that it has already been answered. I am new to the hand tool woodworking (any type of woodworking for that matter…).
I followed Paul’s method for flattening the back of my plane iron using sandpaper and all was good. I have now managed to get hold of some Aldi chisels and I want to flatten the backs of these. I also now have some diamond plates that I use for sharpening.
Would I be able to flatten the backs of the chisels on the diamond stones instead of the sandpaper method?
Thanks in advance
Paul
your mileage will vary but I use sandpaper at 80 grit on a piece of glass. Unless you have a coarse stone at this grit lapping is going to be time consuming on a sharpening stone. Even a coarse diamond stone isn’t really coarse, it’s 220 or 320, it just won’t remove metal quickly You’re better off sticking with coarse sandpaper starting at 80 for the bulk of the work then work your way up to 2000 which will put a mirror finish on the back. Whether you choose to go beyond that is a personal choice.
5 February 2015 at 3:33 pm #124400yes and they will do the job, but sandpaper is a damn site cheaper when it comes to flattening backs
Thanks very much for the speedy reply gents! I hadn’t considered the grit at the lower end of the scale. I think my coarse stone is 300, so as you rightly point out it would take far too long.
I will stick to the sandpaper method.
Again thanks for clearing that up guys.
Paul
One thing to note once you’ve flattened the back is the subsequent removal of the wire edge you’ll develop when sharpening. Be sure to keep your final grit handy on a flat surface for the removal of the wire edge. Removing this on either the 1200 grit diamond stone is not great, and using a leather strop is an even worse idea.The strop will undoubtedly round the edges, and you’ll lose the fine control you gain from a perfectly flat back. Now this depends entirely on the work you carry out, on very fine work, this is very apparent and I’ve experienced it for the worse using this method. On plane irons which do indeed wear on the back, you should be honing the back each time you sharpen, because the prevailing mentality is that you only sharpen the back once, which is clearly nonsense.
When you flatten the back of a plane iron, lets say you know it is flat about 15mm up from the cutting edge because that is where the grinding/lapping/polishing was taking place. How is that portion going to become not-flat? If it is still flat why are you flattening what is already flat? That does not make sense to me.
Hi Craig. I don’t dont believe it’s rubbish. In fact for the cost of some sandpaper and some honing compound, you can definitely find a working edge, but I just done believe it’s as good as it claims, and unfortunately does have it’s downs. I’ve used this method for a while and found if you introduce the three menzerna metal polishing compounds instead of the single green compound, you can arrive at an even better edge, and those compounds are quite cheap.
I am only trying to point out problems I had been having, and perhaps it may be of help to somebody else. On a chisel using predominantly for paring, there is little wear on the back, but a plane iron does show wear, and so should be refreshed each time for a better cutting edge. My point above, perhaps not so clear, was that after a while of pulling the back of chisel on a strop, you will indeed round the edge, which is not desirable.
In working I’ve found this step isn’t required as such, but does help to achieve a much better cut when finish planing or tasks where a much finer edge helps.
Apologies if I offended you or Paul, Craig.
10 February 2015 at 8:19 pm #124549@vips hi to say a method that has been tried and tested over many many years and used very successfully as “clearly nonsense” is a sweeping statement and one that i wouldn’t use unless i’d performed the task as many times as Paul and other members of this forum/site,not all methods suit all people .
I agree the method has been used for many many years. In Japan they have used finer natural stones for many years too, and from what I’ve read, have always resharpened the ura (iron back) with each sharpening, which I doubt was without thought. If you enquire with any major japanese plane iron maker, they will confirm back wear is the reason for resharpening the ura carefully each time. I’ve found it helped find a lot sharper edge for finish planing when done well on western irons too.
I know we can delve very far into sharpening, but I simply wanted to point out a mistake which at least I made. This is only applicable to chisels. Like Paul does in his sharpening video, he uses the strop to pull the burr once sharpened on the back. I found my edges were rounding over (after a while), and I could no longer pare into corners very well, hence my suggestion for keeping the final grit used to flatten the back to always hone the back to remove the burr, alleviating the problem, which helped me a lot.
Perhaps I’ll avoid the sharpening threads as it seems quite a sensitive topic.
vips,
Hi Craig. I don’t dont believe it’s rubbish.
In fact for the cost of some sandpaper and some honing compound, you can definitely find a working edge, but I just done believe it’s as good as it claims, and unfortunately does have it’s downs.non-sequitur
Craig11 February 2015 at 6:17 am #124562I don’t know why, but sharping methods seem to bring out an almost religious furver. I think the point is to find a method that works for you and stick with it. If your tools are sharp enough to do what you want them to, then they are sharp enough and there is no “one true way” of getting there.
I don’t personally use Paul’s method of sharpening. I use a method that works for me and allows me to get back to woodworking. After all, I sharpen so I can work wood, not the other way around. 🙂
Couldn’t agree more Peter. I have done lots of reading on this and it gets very confusing. As a total beginner, watching Paul Sellers show me how to do it was just great. I tried it, it worked for me ( Well I think it did…) so I will continue to use this method. There are many different methods \ opinions out there, it is what is best for the individual.
Thanks for everyone’s advice and insight on this.
Paul
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