Another Spokeshave Challenge

[RobinW]

This week my father gave me an old wooden spokeshave which he has had since pre 1953, and its previous owner was a retired cabinet maker. The spokeshave is therefore well over 60 years old.

The following photos show the before, during and after, as I resharpened it. I started off using a Japanese waterstone, and as there was a fair bow in the blade, it was taking its toll on my finger joints, so I tried the Tormek - freehand - a process I'm not that comfortable doing.

Flattened the back using the side if the wheel (something I would prefer not to do), inside face of blade across the wheel holding on by the tangs; then finished both using the honing wheel.

None of the jigs I have are suitable for holding this blade due to the very narrow depth of the blade and also the sharpening of both faces use full depth, so it can only be held by the tangs.

The whole process was a bit precarious due to the very narrow depth of the blade, difficult to hold steady, and I knew I was achieving the desired standard by the blood running round the stone! (The ends of my fingers were getting rubbed by the stone.)

I've re-assembled the tool and it makes a really good cut.

So here's the challenge, has anyone else else sharpened this type of blade on a Tormek and what jig did they use (if any)?

[Herman Trivilino]

It's hard to tell from the photos, would the HK-50 been of any help?

[RobinW]

The whole blade (inside and outside surfaces) are ground, and the blade is only 10mm (3/8 inch) deep front to back.  I find it hard to told due to its size (the ends of my fingers are still very sore this morning), and I don't see how it could be suitably held and supported at the right angle using either the HK50 and SVD110. My fingers would also get in the way!

Any jig like the SVM45; SVM140, SVX150 etc which grip part of the blade are unsuitable.

I am toying with another idea (bit radical) - might have to make another wood mock up - or drawing and see if it has possibilities. (I can see another day spent away from what I should be getting on with!)

[Herman Trivilino]

I wonder ... Could you put small vice-grip pliers on each tang and use them to get a better grip while using the HK-50?

[RobinW]

I have an idea how to do this. It us similar to what I am about to post under another new jig for various blades, only it will use a U shape at the end which will clamp onto the tangs. However it is pretty late here so I'm in for the night.

[RobinW]

Herman - If you look at the post I have just done concerning a new jig for various blades, I had a quick look at taking that jig and modifying that for the blade in this old wooden spokeshave.

What I intend doing is to cut a rectangular shape out of the front edge, so making a jig which is U shaped at the front and the sides of the U match the tangs of the blade. The screws would then be adjacent to the tangs of the blade so clamping it.

Then swing the whole thing to get the blade face at the right angle for grinding.

This jig would slide over your HK50 and the jig allows a good grip of the blade.

It's now on the agenda. However I would like to get hold of another blade to practise with, as taking the blades in and out of the wooden spokeshave causes the holes on the spokeshave to become elongated and worn, and they are difficult to repair. It's in the pipeline.

[RobinW]

Last week I got hold of a spare blade for a wooden spokeshave, and also a complete wooden spokeshave (which was in a bad way!), so I was now in a position to try my idea for a suitable jig.

I didn't use the blade from the wooden spokeshave shown in my previous post as removing and replacing the blade tends to ruin the insertion holes in the handle and as I have this tool working beautifully, I didn't want to upset it. Also blades tend to be fitted individually to the wooden handle so swopping around is not an option.

The following photo shows the handle with its blade and another blade.



So I made my jig using 6mm thick acrylic sheet, cut as shown in the next two photos. I drilled two 6mm holes to align with the blade tangs and as the tangs are tapered just tapped the blade in and it was held fine.





I made the notch fairly long so that the jig didn't foul on the Tormek wheel when set at an angle of 25 degrees. This was a problem I encountered when trying the small knife jig, due to the shallow front to back size of the blade as shown below. I did try resting the jig on the tool rest SVD-110 but got on probably easier as shown.



Then the penny dropped!

Whilst I could grind the inside of the blade by moving it back and forth sideways, it dawned on me that the blade is curved (concave surface to the wheel) so I couldn't get a proper even grind. I was trying to get the concave curve ground over a wide flat surface! So whilst this would work well with a straight blade as I did previously, it wasn't working well for this curved blade. The jig certainly gave me a good grip on the blade and I could control it better than with just bare fingers (which I tried). To get blades of this size and radius done on the Tormek it would require a crowned wheel! I'm certainly not wearing down my wheel to such a shape for the benefit of two old spokeshave blades!!!

So I resorted to the methods used by many craftsmen of ages past - ie do it by hand.

I flattened the backs on 800 grit self adhesive aluminium oxide sheet (which can be lubricated with oil or water), stuck to a piece of float glass. I also honed it up using the honing wheel on the Tormek.

I filed the inside edge of the blade using the same same type of sheet stuck to a curved wooden former.

I did try hand holding the blade on the honing wheel, but it was not that easy, and I found I tended to dull the edge, so resorted to dressing it with finer grades of grit and the wooden former.

I do not have a handle to suit the spare blade, but it was sharp enough that I could use it fairly well just by holding it with my fingers. I haven't tried the longer blade yet as its handle had broken into three pieces and has just been pinned and glued together.

The last photo shows the original straight bladed spokeshave (upside down) and this week's two curved blades.



Moral of the story - jigs for straight blades no problem; curved blades need a domed or crowned wheel or done the old fashioned way.

*Apologies if the photos are a bit big - just found out the settings I should have used to make them smaller.

[Rob]

Dam good experiment though Robin and 10/10 for a real good try. 

[mike40]

I thought your plastic jig was brilliant and simple Robin. Too bad it didn't work out with the (concave?) blade, but at least it will work of the other shave. This is a good inspiration to us new Tormek users towards problem solving for 'difficult' tools.

[Herman Trivilino]

You could more easily get a crown in the surface of a dry grinder wheel.  If you had the BGM-100 you could use this jig to sharpen that concave blade.

[RobinW]

Herman - You have me beat with your comment. The BGM-100 is the bracket and bar for clamping to the bench which is illustrated in the sales information with the jig for grinding woodworking gouges. Neither of which would hold a spokeshave blade of this type. If the BGM-100 was used with say the small knife jig, the same problem would occur as with the T7 in that the blade with its narrow front to back dimension is prevented from meeting the wheel at the right angle due to the jig fouling the wheel.

So the only way I could see how to do this, as previously described, without using fingers only, was to make something which held the blade by the tangs. If the T7 had a narrow wheel this plastic jig would have worked for the curved blade as there would be enough room to radius the blade without having the tangs interfere with the sides of wheel.

At the moment I still have all ten fingers so there's no way I'm going to my narrow wheel dry grinder which whistles along at a few thousand rpm trying to hold this blade by fingers only! I could use my plastic jig holding the blade with the dry grinder, but I only use that machine for quick imprecise grinding, which is why I bought a T7 for proper sharpening.

Most of my career was spent in control systems for the marine and offshore industry and in our workshops we had machines ranging from the size forum members would have at home to those as big as a bungalow! But of all those machines, I find dry grinders one of the most frightening machines going. I've had and seen a few near misses, and I am very wary should I need to use one. A major reason why I bought a T7.

It didn't take long doing the curved blade by hand. I did the outside face using the T7, abrasive paper on glass and waterstone, and the inside using abrasive papers on a former for the inside edge.

However it was achieved, having a really sharp spokeshave blade (for both metal and wooden tools) has allowed me to quickly get up the learning curve with these tools. Like having sharp planes and chisels. I can now pick these up and do tasks with confidence and pleasure.

[Herman Trivilino]

I was talking about using your jig with the BGM.

[RobinW]

Ah ha! I understand now!

Yes I agree it would work, just watch the temperature doesn't get too high and melt the plastic!

The jig would be better with a narrower handle and rounded on its underside so that it could be rolled easier to radius the blade.