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On the Stieff rebuild I am undertaking, I am replacing treble bridge caps due to extensive cracking. I've completed the cap replacement, and will shortly begin the notching and pin replacement.

I am curious about the original notching technique. I've included shots below of the tenor bridge -- I don't have shots in profile of the treble bridge. It appears that the notches are cut on a curve away from the the pins. Was this done with a straight chisel, varying the angle of cut as the cut progresses? Or was this curve achieved with a different chisel type, or other tool?

I have not yet done a mock up and experimented with chisel techniques, but I am curious what you all can tell me.

Tenor bridge showing curve of notching:
<a href="http://flickr.com/photos/duanemcguire/1014145518/in/set-72157601225330258/" title="More photos on Flickr.com">
<img src="http://farm2.static.flickr.com/1267/1014145518_1d9642233e.jpg?v=0" border="0"></a>



Original treble bridge cap:
<a href="http://flickr.com/photos/duanemcguire/723068810/in/set-72157600653743304/" title="More photos at Flickr.com">
<img src="http://farm2.static.flickr.com/1390/723068810_a1a9d007a6.jpg" border="0"></a>



New treble bridge cap:
<a href="http://flickr.com/photos/duanemcguire/1272506276/in/set-72157601246776215/" title="More photos at Flickr.com">
<img src="http://farm2.static.flickr.com/1037/1272506276_d0f5b3991b.jpg?v=0" border="0"></a>




Thanks in advance for your time, experience, and observations.

That is created by technique. Both by the chisel and by the side cut. You kind of scoop the wood with the chisel instead of pushing strait down.
Practice on some scrap.

The first bridge I made 15 years ago was a practice bridge. I made the entire root treble to tenor for a grand. Capped it then drilled, notched and pined it. To this day it hangs on my shop wall.

It was a great way to learn the craft of bridge making.

A friend of mine who makes violins points out that it is the last cuts where neatness counts. You can rough it out, but it is your last cuts that should be smooth and sure.

Thanks for your inputs. I am very grateful for your responses. Though my intuition was correct, the voice of experience is worth a lot!

I'll certainly work on technique before touching that new bridge cap.

I'll post some photos here, when the work is complete.

Thanks.

Flat chisel. Flat side up. Mega-Ultra sharp and polished until you can see yourself in it.
Even the edge on new decent quality chisels is not refined enough.

This is the chisel that they use at M & H
<img src=https://www.pianoworld.com/Uploads/files/2007Tour3.jpg

Woodfab, the chisel used at Mason and Hamlin IS quite nice.

Consider this though, the old timers did not use a flat chisel.

Look at some of the old bridges.
They were not done with a flat chisel.

A flat chisel's edge is not pointed in quite the correct direction.

Larry, do you find that A curved out notch works better than a straight notch?
I like the look of a curved notch and thought it might be better than a straight notch but when I went on the M&H piano tour they told me the straight notch works very well.

I have not done tests to determine that one is better than another. I do think it is critical that the string clear properly.

I happen to like the "style" of the older notch.

Additional note,

As folks may know, chisels are denoted by scoop and sweep.

Bridge chisels of old are "zero" sweep and a slight scoop.

The ones I know of are custom made and duplicate the "old" style cut very nicely.

Here is how I joint my bridge caps.

It is a large file pic so here is the link.

www.ejbuckpiano.com/Coe/Sound%20Board/BridgeScarf.jpg

I'll photo a completed bridge and put it up.

Here is an old photo of some bridge notching I was doing.

www.ejbuckpiano.com/Charlie/Bridges/Notching.jpg

Larry,
I've never seen chisels designated by "scoop"...is this the degree of "swan-neck", like those used to clean the bottom of a mortise? I'm assuming anything other that the generic swan-neck would certainly be custom. Zero sweep, I know!!

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Thanks again for your experience and observations. I'm interested in alternate chisels, now that Larry has suggested it, but I decided to go ahead and do this first bridge notching with flat chisels. I used the techniques described by Rod and Craigen above. I'm pleased with the result, but there were some learning moments (as I expected ... this is a learning project, not a commercial job).

Photos of my work are below.
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<a href="http://www.flickr.com/photos/duanemcguire/1441009874/" title="Photo Sharing"><img src="http://farm2.static.flickr.com/1309/1441009874_e408b82f60.jpg" width="500" height="375" alt="Bridge Notching" /></a>

<a href="http://www.flickr.com/photos/duanemcguire/1440149633/" title="Photo Sharing"><img src="http://farm2.static.flickr.com/1123/1440149633_57cbaa9f29_o.jpg" width="1280" height="960" alt="Bridge Notching" /></a>

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The second photo above shows some of my "learning". On some of the notches in the lower section of the bridge, you can see some markings on the end of the notch. I came to realize that these marks were made by the top of the chisel as it exited the cut. This is from the ridge back of the chisel. I was making the dish cut with the flat side of the chisel facing up. So a different back profile would be better for this work. Also at the fourth unison in the upper section, you can see an awkward transition from dished notching to straight cut notches. I discovered that the length of cut didn't allow for an attractive scooped notch, but aesthetically it would have been better to change at the section break, I think.
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Larry, your works looks very nice and shows lots of experience. Do you think that just a straight cut is easier and a better choice for beginners?

Thanks Gene,


I suppose so.

I was thinking that the choice for tools will determine results, regardless of experience.

Duplicate

Duane, Great job for a first go around.

You are sure getting a taste for the process ...

I think that, with practice and the right tools, you can easily take the scoop right through the treble. .

Larry,
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Thanks for your encouragement, compliment and additional remarks. Indeed, I finished the notching this evening, and I found technique that would allow me to scoop at the top of the treble. On the lower end, I had found that the chisel with the flat side up worked well, but in the upper treble with shorter working area a nice scoop is produced with the more conventional orientation of the chisel. I then went back and scooped the ones I had cut flat yesterday.

I'm totally convinced that custom chisels would produce a better result more easily.

Larry, can you tell me how to proceed with the custom tool route? I'm guessing the tools you have were made years ago, so this might be a hard question. Above you say that the bridge chisel should have "zero" sweep and a slight scoop. I'll do some googling on that, but can you perhaps also suggest where to go looking for a supplier?

You and everyone here have given me so much!

Thanks!!!!
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