Adventures in balancing a bow...

[Michael Appleman]

Hello everybody. I hope you're all doing well and have been enjoying the holiday season!

I haven't posted in a while, but I've been enjoying the information, humour and observations shared by all of you, and I thought I'd share a little adventure I had recently regarding an interesting bow.

I picked up this very nice early german bow, maybe a CW Knopf or a Schramm (I've got to show it to an expert one of these days), several years ago, and it's an excellent bow for drawing sound, but unfortunately VERY tip heavy. It only weighs 59g total, but it's balance point is 1.5cm farther up the stick than even my most tip-heavy usual-use bows, so it feels quite cumbersome whenever playing anything with bouncing or fast bow and string changes. For playing purposes, I had a replacement frog made, but my bowmaker put back the original button, which is quite short with very thin hammered silver rings.

It is very light, coming in at 3g with the screw, whereas most of my other bows have button/screw combos that weigh 5g. I played around with attaching some weight to the button, and found that adding 3g to the button brought the balance point back towards the hand 1cm, and made the bow quite comfortable and manouverable, without bringing the overall weight up too much, so I asked my bow-maker friend to make me a new, heavier button. Making a 5g button wasn't a problem, a full length silver cap would do it, but getting that extra gram without making an unnaturally long button would be tricky, so he had an original idea that he thought would do the trick. He slipped 1g of mercury between the silver cap and the ebony center. Mercury is incredibly dense, and the button did the trick for balance, and was looking good. After bringing it home, I opened the case the next day to find the new button looking strangely cloudy. As I tried to polish it, I realized it felt wet...the mercury was amalgamating with the silver and bleeding through! I washed my hands and put the button in a plastic bag right away. At this point, the button is liquifying as the mercury is alloying itself with the silver!

So my friend is making me another button with a double or triple end cap, but in the mean time, my sons got me a 3d printer for xmas, and I decided to try to make a 3g plastic cap to go over the original button. Of course it looks silly, but it does the trick for balance. I can finally use this bow for all around playing, not just Adagios and Largos!

Best wishes for the New Year to all of you!!

[Blank face]

Hi Michael,

good that you simply took mercury and not plutonium to the button for weight adding purpose. So, as always, I would recommend to leave everything as is before experimenting without being able to overview all possible consequences.

The bow looks nice, my guess would rather be an early 19th South-German or Mittenwald bow than Knopf or Schramm, but due to missing clear references this can be speculation only. In my experience most of this early German bows are head-heavy compared to later ones, the construction of the sticks was different, more mass and thickness in the upper part.

All good wishes for the holidays! 

[Rue]

When I read mercury...I thought "uh oh". Then I wondered why someone has a supply of mercury on hand?

But you had an adventure! 

Now that you have the weight figured out, I hope the next incarnation is both functional and attractive...and not wet!

[Brad Dorsey]

I have never heard of the use of mercury in a bow before.  Has anyone else?

[GeorgeH]

4 hours ago, Michael Appleman said:

He slipped 1g of mercury between the silver cap and the ebony center.

That is insane.

EDIT: It should be disposed of as hazardous waste ASAP. 

[Rue]

Mercury does evaporate (and your body gets rid of it as well). Anyone know how long it takes?

And I'm talking about very small amounts one may come in contact with...not large amounts or acute mercury toxicity.

[GeorgeH]

https://www.who.int/news-room/fact-sheets/detail/mercury-and-health

 

[PhilipKT]

Michael! Haven’t seen you around for a while, glad to read a post from you.

[Blank face]

It seems that your friend could get into serious legal trouble violating several regulations about  storage, dealing, applying warnings etc. when handling mercury. That's all not very funny, just imagine somebody would buy such an artefact without knowing what it contains. I hope that there weren't others before with such ideas, in case I'll ever come about a similar manipulated button.

https://www.legislation.gov.uk/eur/2008/1102/contents

[PhilipKT]

I’m curious as to why a tiny bit of melted lead wasn’t considered? I have owned a couple of bows that had a little bit of melted lead added to the head to increase tip weight, any reason why it wouldn’t work on the button?

[Bill Merkel]

When I was a little kid, we'd shine up silver dimes by rubbing mercury on them.  Quarters too, if we could get our hands on one.  Makes them real shiny.  We didn't drink it, but it was considered perfectly safe to be around and handle

[duane88]

I repaired an AMerican violin many years ago. Other violins by this SD maker had dowels in the corner blocks, I assumed as part of the construction process. The last one I took the top off of, 2 of the dowels stuck to the top. Looking inside i saw something shiny, and upon turning the corpus upside down I had Mercury drop onto my bench! By weight, each corner block had 1.1 gm. I contacted the owner who wanted it placed back into the block. I did warn him to never try and fly with that particular fiddle. Why? I don't know.

[Brad Dorsey]

1 hour ago, PhilipKT said:

I’m curious as to why a tiny bit of melted lead wasn’t considered?…

Since mercury is denser than lead, a given volume of mercury would add more weight than the same volume of lead.

[Barry J. Griffiths]

If the frog mortise allows room for it you could put a rectangular piece of lead under the frog block. You could also use a heavier gauge of wire for the winding. I once needed more weight at the frog end and substituted a sliver slide instead of ebony, with an abalone facing.

[HoGo]

He could use tungsten. Or gold, though that would be a bit more expensive.

[Blank face]

I can't see why it's better to manipulate the weight of an historical bow with any of this cheap tricks than just to buy a bow which is satisfying one's need from the start. When it comes to selling such a bow without mentioning such tricks it comes close to crookery anyway.

I don't want to be surprised by some lead chunks floating around in my shop while making a rehair neither.

[martin swan]

1 hour ago, Blank face said:

I can't see why it's better to manipulate the weight of an historical bow with any of this cheap tricks than just to buy a bow which is satisfying one's need from the start. When it comes to selling such a bow without mentioning such tricks it comes close to crookery anyway.

I don't want to be surprised by some lead chunks floating around in my shop while making a rehair neither.

I once bought what I thought was a mint JA Vigneron cello bow of an ideal weight. On taking off the lapping we found a strange mark on the stick. The bow had an 8 gram tube of lead shoved up in front of the frog mortise - the twit who had done this had reamed out the stick to the point where the channel broke through the wood.

And it had an impeccable certificate ...

 

[Michael Appleman]

On 12/29/2021 at 9:28 PM, Blank face said:

I can't see why it's better to manipulate the weight of an historical bow with any of this cheap tricks than just to buy a bow which is satisfying one's need from the start. When it comes to selling such a bow without mentioning such tricks it comes close to crookery anyway.

I don't want to be surprised by some lead chunks floating around in my shop while making a rehair neither.

I hope no one reading my initial post thinks I'm in favor of any of these invasive lead/tungsten/mercury/plutonium tricks! I personally am in favor of making replacement frogs and buttons to preserve pristine or fragile originals, and tweaking weight or balance for personal playing preferences is not a sin in my eyes if it's done in easily reversible ways that don't modify any original parts. Drilling out original wood from any part, stick, frog or button is pure vandalism in my opinion!

[mood2000]

How to Measure the Balance Point of a Bow

 

https://www.youtube.com/watch?v=ATrFNYJi8eQ