Scary Sharpening – More thoughts

If not obvious – I’ve been having a sort of reconciliation around my thoughts on sharpening. Sharpening woodworking tools has always been something that I thought I just had to know how to do in order to do hand tool woodworking. That is – I had to know how to do it – I didn’t have to be great at it. My recent experience with trying to get my low angle jack plane working on a homemade shooting board has made me question all of this again.

So as things go – I have sort of ended up back where I started. When I took my first woodworking class with Mike Siemsen he taught my how to sharpen using sandpaper on a piece of glass. After much reading and research I started thinking about getting back to that. Namely – because I was having issues flattening the back of the low angle jack plane iron. I came across many videos – but this one really grabbed my attention. In this video they talk about using 3m diamond lapping film. Up until this point, I had been using sandpaper – but just normal sandpaper and using it dry for doing sort of major lapping or reshaping. So I decided to give his 3m film a try…

Lee Valley sells the stuff for about $4.50 a sheet. Not cheap as far as sandpaper goes – but folks seems to say that it can last a very very long time (upto 6 months with daily use) and considering that you cut the sheets and get 3 strips from each sheet I figured it might be worth at least trying.

So the idea is pretty simple. The sheets are PSA backed – so you cut a strip and then put it on the glass to use as your sharpening medium…

Cutting the sheets was easy – applying it was a more time consuming matter…

The higher the micron level – the easiest it was to apply as the sheets were fairly stiff. As I got closer to the lower microns the sheets were prone to getting bubbles in them. The roller helped – but to get the sheets straight AND flat took some serious focus and work. I’ve read that some folks apply the sheets with water so they can float them on and then let the water evaporate and the glue dry. I might give that a try next time.

So after I got a 100 micron, 30 micron, 15 micron, and 3 micron sheet applied to the glass I went after the back of my low angle jack iron…

The process was time consuming – I think I’ll get more used to it but to get to the last sheet took me about 30 minutes. That said – I think the back is finally flat! I sharpened the bevel with a honing guide using the same process and I think I got a good edge on the blade.

That said – Im not sure if its any better than the edge I got from my Spyderco stones. The blade was sharp – but maybe just as sharp as my last process? I think that I will for sure keep using this process for flattening plane irons. But for honing I think I might stick with the Spyderco stones.

I’ve also changed my mind on primary and secondary bevels a little. It makes sense to me establish a primary bevel – but then really you should have a higher degree secondary bevel. Otherwise – each time you hone you’re honing the entire blade which seems like a waste. I’m thinking about investing in a Tormek for grinding primary bevels, the Spyderco stones for honing, and then perhaps the 3m paper for flattening the back.

I’ve also experimented with honing compound after I’ve honed on the paper or stones. I just can’t get the hang of it. I’ve tried stropping with compound many many many times and all it seems to do for me is dull the edge. For me – having a flat surface that I can do final honing on just seems to make more sense. So I’ve ordered a 12k water stone that I hope to use as my final step in honing. If 12k isn’t sharp enough – I don’t know what will be.

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