I think the re-hair on my bow is too short…

[outofnames]

I just had my bow rehaired by my usual luthier.  It’s cold and dry here right now since we’re in the dead of winter.

Anyway, at conclusion of first orchestra practice post-rehair, I was loosening tension and ended up completely unscrewing the frog from the stick because the hair never got slack.  I couldn’t get it back on because it was too tight.  When I got home I finally managed to get the frog back on.

Next morning, all the excess tension was gone.

Then, last practice, same issue.  

So I’m thinking because the church hall is very warm with good humidity, my bow is expanding and hair may be too short….because the luthiers shop was low humidity and the length of the hair was cut in that environment.

Is that possible?  I don’t know how much the hair stretches but it’s been a month.  

No issues at my house but I don’t keep it super or warm and it’s on the drier side.  

[Shunyata]

Church hall is very warm which creates very low humidity and makes the hair shrink very markedly.  (Humidity is a function of both moisture level and temperature.)

It happens.  A looser hair job will help with this issue.

Humidity that low isn’t great on the violin either… although it is slower to react than bow hair.

[outofnames]

1 hour ago, Shunyata said:

Church hall is very warm which creates very low humidity and makes the hair shrink very markedly.  (Humidity is a function of both moisture level and temperature.)

It happens.  A looser hair job will help with this issue.

Humidity that low isn’t great on the violin either… although it is slower to react than bow hair.

Actually, I think it’s more humid there.  And the wood of the bow is expanding causing the problem.

[duane88]

19 minutes ago, outofnames said:

Actually, I think it’s more humid there.  And the wood of the bow is expanding causing the problem.

No. What Shunyata said.

[M Alpert]

Horse hair is very sensitive to humidity, much more than wood. 10% change in relative humidity can mean approx 3-5mm in hair length. So if it is too short after a few hours somewhere, then it is drier there than elsewhere.

If you can take the frog off when it is too tight to relieve the tension on the stick, the hair will eventually stretch from usage (usually in a few weeks), less or more depending whether your luthier pre-stretches it during rehairing.

Good players use their bows at tension for many hours a day, so although it is important to let the stick rest, most bows will not be ruined by even a few weeks of being under constant tension, in my experience.

[outofnames]

45 minutes ago, duane88 said:

No. What Shunyata said.

Really?  Ok, that’s why I asked.  I guessed the problem but seem to have it backwards.

So if no problem at home but way too much tension at the church hall after two hours that means it’s much drier there than at my house and the hair is shrinking as it dries.  
 

Yeah, I’d never had that happen before.

 

[Nicholas Lewis]

57 minutes ago, M Alpert said:

depending whether your luthier pre-stretches it during rehairing

Any good methods for this? 

[Chamberlain]

It sounds like it was rehaired slightly too short for the winter season and low humidity. If it hasn’t been long since the rehair the luthier will most likely fix the issue very quickly and probably at no cost if it indeed was done too short. You should be happy with it and not risk damaging your bow. 
Some rehair techniques allow for extra winding knots in the frog that can be removed to give a little length when needed also. The luthier could do that quickly too. 

[David Burgess]

3 hours ago, outofnames said:

So I’m thinking because the church hall is very warm with good humidity, my bow is expanding and hair may be too short….

Wood expands and contracts very little "along the grain" with humidity changes, and a bow has low enough permeability that it would take a very long time to change in length.

The bow hair, on the other hand, is very much the opposite.

[Andrew Victor]

YES! Be careful. I have seen a bow stick crack and fall apart in an orchestra rehearsal because the room was too dry.

 Monitor your bow carefully and frequently while you play in that room and loosen it accordingl

Also check your bridge. (:-)

[outofnames]

5 minutes ago, Andrew Victor said:

YES! Be careful. I have seen a bow stick crack and fall apart in an orchestra rehearsal because the room was too dry.

 Monitor your bow carefully and frequently while you play in that room and loosen it accordingl

Also check your bridge. (:-)

That’s the problem, I couldn’t loosen it all the way without the frog coming off.  I never had that issue before and it surprised me when I was watching the tension and realized I was holding the screw in my hand.

It wasn’t under full tension but definitely not loose.

I had it redone about a month ago so maybe I’ll call him.  He does all my work and he’s rehaired it before.

[David Burgess]

10 minutes ago, outofnames said:

That’s the problem, I couldn’t loosen it all the way without the frog coming off.  I never had that issue before and it surprised me when I was watching the tension and realized I was holding the screw in my hand.

If you are in the US, much of the country has been going through an unusually cold spell, resulting in unusually low indoor humidity.

[Deo Lawson]

Low humidity will cause hair to shrink.

You can stretch the hair at home by wetting it and going over it with an iron, being careful not to rest in one spot. I use this method to make a nice ribbon on my rehairs.

Wipe the rosin off with alcohol first or your wife will not be happy about the state of the iron. Avoid touching the stick with alcohol.

[outofnames]

12 minutes ago, David Burgess said:

If you are in the US, much of the country has been going through an unusually cold spell, resulting in unusually low indoor humidity.

Yes and yes.  Extremely cold where I am.

[Chamberlain]

48 minutes ago, outofnames said:

That’s the problem, I couldn’t loosen it all the way without the frog coming off.  I never had that issue before and it surprised me when I was watching the tension and realized I was holding the screw in my hand.

It wasn’t under full tension but definitely not loose.

I had it redone about a month ago so maybe I’ll call him.  He does all my work and he’s rehaired it before.

Yes, definitely call him. The weather right now is tricky for rehairs. I’m sure he will understand and be happy to help make it right for you. Also playing with hair too tight can sometimes cause other issues with the bow or frog/screw/eyelet so it might be good to just have it checked over. 
You shouldn’t have to perform DIY rehair alterations when you have a trusted luthier. That’s the perk of working with a luthier and getting professional level rehairs. Unless you want to then have at it (:

[M Alpert]

3 hours ago, outofnames said:

That’s the problem, I couldn’t loosen it all the way without the frog coming off.  I never had that issue before and it surprised me when I was watching the tension and realized I was holding the screw in my hand.

It wasn’t under full tension but definitely not loose.

I had it redone about a month ago so maybe I’ll call him.  He does all my work and he’s rehaired it before.

Definitely let him know! A short rehair can happen to the best of us, and any rehairer who cares will gladly fix it for you.

[M Alpert]

4 hours ago, nrlewis said:

Any good methods for this? 

Well. Proceed with caution. I know some people make a fancy jig for this - I haven't.

I have had success by dividing the hair in half and putting 2 matchsticks or toothpicks between the hair and the stick, effectively stretching the hair behind the stick (when the hair is damp). Let it dry some hours under a bit of tension - 2-3 cranks of the screw (some do overnight, I prefer to check it regularly to be sure it is not too tight).

Never had a bow head/tip area break like that. But I admit, the possibility makes me nervous. I do check the head area for visual signs of weakness, and avoid doing this on very valuable bows.

I prefer to rehair "just right", and let the owner stretch it by playing. But I know some great makers do it this way as a technique.

I am interested to hear others' ideas about this.

[M Alpert]

3 hours ago, Chamber said:

You shouldn’t have to perform DIY rehair alterations when you have a trusted luthier. That’s the perk of working with a luthier and getting professional level rehairs. Unless you want to then have at it (:

Agreed.

[Guido]

I think you shouldn’t do anything.

if you don’t have the problem at home and only in this one location temporarily, this will be fine. Bows are regularly under tension for many hours at a time.

whats more, the hair will stretch with use and time, add the impending weather change to increased humidity and you will have plenty long hair.

if you lengthen it now it will likely be too long very soon.

[outofnames]

7 hours ago, Andrew Victor said:

YES! Be careful. I have seen a bow stick crack and fall apart in an orchestra rehearsal because the room was too dry.

 Monitor your bow carefully and frequently while you play in that room and loosen it accordingl

Also check your bridge. (:-)

Yeah, after the first rehearsal with the new hair and the problem I had I found myself loosening the bow a few times as practice went on as the tension was increasing.

I’ll monitor and then decide what to do.  I’m hoping it stretches but I was surprised at how much tension it was under when the frog was fully unscrewed.  It doesn’t happen at home nor at my teacher’s home, just the practice hall.

My bow has a cracked and repaired head (bought it this way from same luthier).  I’m quite protective of it, not because it was expensive (think $750), but because it feels perfect and I’ll never find a replacement.  So damaging it doesn’t really hold much appeal.