Friday, July 25, 2008

Reconditioning old chisels

So, having watched the arm shaving video I was intrigued about how he got the chisel so sharp and, having spent a long hot day working on some old chisels using the Trend Fastrack, I thought I give the sandpaper method a try.

I actually took the plunge and bought the Veritas Mark 2 honing guide, and a very solid piece of kit it is too. I don't have all the grits and I don't have the bench grinder with a buffing wheel, so razor sharp was probably out of the question.

Here's what I did:

The starting point. This is one of the chisels I inherited from my Dad when he died a few years ago. It was pretty grubby.

The first thing I did was use a small strip of coarse sandpaper to clean up the back and sides of the cutting end of the tool.

I used some 80 grit and then some 150 grit to get all the pit marks and rust and dirt of the blade.

Cleaned up, the back of the blade looks like this:

This only took a minute or two and whilst it not a mirror shine it's a long way down the road to becoming a usable tool.

The next step was to work on the bevel. There was a fair amount of material to be removed, and with a grinder to hand and either a tool guide or a steady hand that would have been relatively quick. But I don't have those things, so it was 80 grit paper and elbow grease.

Setting up the Veritas was very quick and simple. Just position the angle guide, set the angle and slide the chisel in and then lock it in position.

This is really a very good guide and I think it is worth the cost (it's not cheap, but you do get what you pay for). My other guides are less costly but much more difficult to set up accurately and repeatably. I suspect that the Veritas will give repeatable settings every time. Of course the angle set on the Veritas doesn't match exactly the angle on the Trend, but then you wouldn't expect that really. 

I did sharpen one chisel using both the Veritas to do the initial work and then the Trend to finish it off. This gave a good edge and was much quicker than yesterday's long toiling, finger aching day using just the Trend.

After about five minutes work I now had a useable, if not razor sharp, chisel. The shavings in the photograph may look rough but they were actually quite fine. 

My conclusion after all this is that I still have a long way to go to get a really sharp edge, but I'm more confident that I can get a good working edge on a chisel and plane iron with less effort and more accuracy than before. Using sandpaper glued to a board is certainly effective for much of the work, and the Trend is always there to give a better edge with more practice.

I used ordinary spray mount (the kind you use for display work and photographs) to adhere the sandpaper to a piece of old plywood. One tip, make sure you glue the paper close to a usable working edge of the board. That makes getting the back of the blade nice and flat for the first stage of the process.

2 comments:

woodtreks said...

I like how you have encouraged the idea of just giving it a try. It seems that many people new to the craft don't buy into the idea of keeping blades sharp. Keith (woodtreks.com)

Richard said...

Hi Keith, thanks for the comment. My woodwork teacher at school, and my Dad after that, always made the point that a sharp tool would always make the job easier to do.

To be honest I know that there is little point setting out on building a decent piece of furniture if you can't sharpen a chisel or a plane iron, so it pays to develop the skill.

So, how do you keep your blades sharp?