Climate and cracks

Hoovorff · Post by **Hoovorff** » Tue Mar 23, 2004 7:05 am

Andrew wrote about some people's "horror of boxwood" cracking.

Are there any special tips any of you can share for climate-control of boxwood flutes? Are there any things that should be done differently from how to care for blackwood flutes?

Thanks, Jeanie

bradhurley · Post by **bradhurley** » Tue Mar 23, 2004 7:10 am

Hoovorff wrote:Andrew wrote about some people's "horror of boxwood" cracking.

Are there any special tips any of you can share for climate-control of boxwood flutes? Are there any things that should be done differently from how to care for blackwood flutes?

Thanks, Jeanie

I have a gorgeous boxwood Bb flute from Mr Wilkes. The tenons warp out of round if the humidity drops much below 40 percent, so in winter I keep it in a sealed Tupperware container with a wrung-out sponge and an electronic humidity gauge inside. I try to maintain the humidity at around 45-50 percent.

Other than that, I've never had any problems. I once lent it to a friend who kept it in a hot, dry house for a week, and when she returned it the tenons had gone oval to such an extent that I couldn't put the flute together. But a day in the Tupperware box brought everything back to normal.

Hoovorff · Post by **Hoovorff** » Tue Mar 23, 2004 7:27 am

I've heard that sealed Tupperware containers can lead to mold. But I guess if you're playing it regularly, and wringing out the sponge, this wouldn't develop.

Thanks, Jeanie

bradhurley · Post by **bradhurley** » Tue Mar 23, 2004 8:38 am

Hoovorff wrote:I've heard that sealed Tupperware containers can lead to mold. But I guess if you're playing it regularly, and wringing out the sponge, this wouldn't develop.

Thanks, Jeanie

If you let the humidity go too high, then mold is certainly a risk. But like I said, I keep a humidity meter in the container. If it gets too high, I just open the lid and let it drop back down to around 45 percent. I've never had any mold develop at those humidity levels.

chas · Post by **chas** » Tue Mar 23, 2004 9:07 am

I've got three boxwood flutes and a half-dozen or so box whistles, never had a problem. I try to keep them between about 45% and 60% RH. I have Tupperwares with cigar humidifiers and also a humidifier in the instrument room. At one point I was pretty anal about keeping all the wooden flutes and whistles in the sealed containers, which are very stable between about 55-60%, but the room is pretty stable except when it's raining, plus I've become a little more relaxed in general.

I have had a few rings come loose, but those are on blackwood and cocobolo, not boxwood.

andrew · Post by **andrew** » Tue Mar 23, 2004 9:09 am

Thinking I was being clever one summer I put a number of old flutes in a tupperware box,with the idea that if the moisture couldn't escape the flutes would be OK .Not only did a rich culture of mould grow over them , but a number cracked .They say you live and you learn .I find both tricky .

JessieK · Post by **JessieK** » Tue Mar 23, 2004 10:05 am

bradhurley wrote:
JessieK wrote:
andrew wrote:you should all go to Ireland...just for the crack.
Hee hee. Pun intended? Craic?

Not to be pedantic, but I remember reading somewhere that crack is the original spelling..."craic" came along later as an Irishized version (just like "seisun" came after "session.")

Hmm...that's interesting! Thanks for the info.

Loren · Post by **Loren** » Tue Mar 23, 2004 12:13 pm

Cathy Wilde wrote:Which leads me to think cracks are not unusual, and also gives the first-year-or-two theory some credence. Logically, this would be when the flute would be subject to the greatest stress, no?

Mmm........no, not necessarily: Cracks are not unusual when the instrument goes to a different climate, but are unusual when an instrument lives at or near the RH it was produced in. So.....A year or ten years, doesn't much matter - if a flute is made in an area where the humidity is say....70% more or less year round, then stays there for 20 years and doesn't crack, no big surprise. Now, take that flute after 20 years and move it somewhere the humidity is 40-50% and a crack nearly as likely as if you were to ship the same flute to the lower humidity area a week after it was made.

Loren

Loren · Post by **Loren** » Tue Mar 23, 2004 12:48 pm

Hoovorff wrote:Andrew wrote about some people's "horror of boxwood" cracking.

Are there any special tips any of you can share for climate-control of boxwood flutes? Are there any things that should be done differently from how to care for blackwood flutes?

Thanks, Jeanie

Jeanie,

Where I work we make quite a few boxwood instruments, several hundred a year, and typically cracking (after manufacture) isn't much of a problem: With boxwood, it's going to crack sometime before or during production, or likely not at all.

As others have said, keep the humidity relatively constant and you'll have few problems. Of course twisting, bowing and ovaling will happen if the instrument is exposed to excessively dry or humid conditions, and too much humidity can also cause very serious mold problems with some boxwood instruments, particularly depending on how the wood was or wasn't processed at the time it was harvested as there is a type of mold inherent to the wood that can go wild with little provocation.

Loren

andrew · Post by **andrew** » Tue Mar 23, 2004 6:30 pm

I think that Eilam can tell us how much boxwood shrinks to an oval section .Is it 10 X as much as blackwood ? This happens a lot not as the wood seasons necessarily but as it ages and oxidises .Sticking holes in a piece of wood along two different axes is asking for cracks !

eilam · Post by **eilam** » Tue Mar 23, 2004 7:05 pm

<I think that Eilam can tell us how much boxwood shrinks to an oval section>

can't say much about it, though I'd imagine it will be similar to the number of bowed flutes Boxwood/Blackwood, it's on a deferent axe, but it's obvious that Blackwood does much less of that.
How ever Andrew - I know what you mean about "live and learn", seems like every time I learn something - it nearly kills me, OK, time for my medicine

Blackbeer · Post by **Blackbeer** » Tue Mar 23, 2004 9:14 pm

Well I don`t usually read threads with the word "crack" in them but this one got long enough that I figured I might learn something from some of the experiences of others. I am paranoide about cracking. I love my wooden flutes and I don`t want any cracks. Now that is a dumb statement as my antique 8 keys, Eb and D in blackwood both have cracks and my Boosey & Sons Pratten`s Perfected piccolo in boxwood is cracked. I just don`t want any more cracks. My rosewood Dixon I have had about a year now with no problems. While I was waiting for it and got antsy Tony would only say it is de-stressing. At that time I hadn`t a clue. A little while back I had the good fortune to try out 4 early American boxwood flutes, all made in the early 18 hundreds. All but one, an F, were cracked. They were the first boxwood flutes I had ever played and I can tell you right now I love the warm sound of boxwood. I wouldn`t care what I had to do to keep one healthy. They just sound so good. All my wooden flutes live in a cigar humidor and 70% humidity. I oil them more then they need and I play them a lot and so far so good. I think there is a crack fairy that just flits about with some sort of sonic wand and gets her jollies with well aimed and random sonic beams pointed in the direction of ones favorite flutes. I have an old bamboo flute that I have hauled around with me for close to 30 years. Could never play it but just couldn`t bring myself to get rid of. It spent 15 years of its life on my sailboat and the last 6 years here in no humidity land. When I finaly could play it and grew to love its sound, out of the blue it cracked. Right in my hand, as I was playing it. Drat that fickled fairy.

Tom

dcopley · Post by **dcopley** » Tue Mar 23, 2004 9:23 pm

Here are some temperature and relative humidity figures from the "World Weather Guide".

Valentia (Southwest Ireland), average readings for 2:30 pm.
January: 49 deg F (9 deg C), 79% RH.
July: 62 deg F (17 deg C), 79% RH.

Indianapolis (US Upper Midwest), average readings for noon,
January: 36 deg F (2 deg C), 69% RH,
July: 86 deg F (30 deg C), 49% RH

Salt Lake City (US, Rocky Mountains), average readings for noon
January: 35 deg F (2 deg C), 64% RH
July: 92 deg F, (33 deg C), 29% RH

These are outdoor readings. You can make a very rough guess at the indoor humidity in winter by using a "dew point and relative humidity calculator" (There are several on the web - Google will find them).

For example, the Indianapolis January readings give you a dew point of 27 degrees F. If you heat that air up to 70 deg F, the relative humidity drops to 20% - just about what my hygrometer reads in the house on a cold winter day, and I'm 100 miles from Indianapolis. For Valentia in January you get a dew point of 43 deg F and an estimated indoor humidity of 43% at 70 deg F.

Hope this helps shed some light on the subject.

Dave Copley
Loveland, Ohio

sturob · Post by **sturob** » Tue Mar 23, 2004 10:01 pm

I don't think that's all that relevant, actually. In 49°F weather, heating the air to 68°F (or higher), which is about room temperature, will drop the RH to the 40% range or lower (depending on how you do the calculation, which is actually really complicated; Dave's estimated indoor humidity assumes conservation of moisture). I'm not saying it's not good information, I'm just being fussy and bossy.

Likewise, central heating with humidification is a lot more common in North America than it is in Europe.

So, unless the Irish keep their flutes outside, they're subjected to the same environmental stresses as those in North America.

If you're in a climate that is hot and wet, it's unlikely that A/C will drop the RH a whole heck of a lot.

The other thing to remember is that warm air holds a HECK of a lot more moisture than cold air. . . hence (among other things) the fact that heating the air really drops the relative humidity.

I'm not sure about Loren's comment about flutes and cracks and not necessarily cracking when a flute is kept in the same RH it's made in. The equilibrium, it's been demostrated, that exists between the wood and the air (relative to RH) is a very shallow phenomenon, particularly at first. I think that what we seem to see anecdotally as an early-crack phenomenon relates to the fact that the bore (and perhaps the outside) haven't seen the RH of the ambient air for very long . . . get my drift?

Also, vis-à-vis flutes made in areas with high RH, versus low RH. I seriously think we should put hygrometers in workshops and see how much they fluctuate. I grant you that, taking Ireland as an example, the RH indoors in the summer, in a country in which you don't need air conditioning, is nearly the same as outside. The winter is a completely different matter. Do folks routinely humidify their workshops? (How about von Huene? I think we have an insider for that place.

)

Oh, yeah, with regard to heating and RH and A/C and RH: heating drops the RH because warm air can hold SO much moisture than cold air. So, since the absolute humidity remains constant, the relative humidity drops. Cooling the air should actually increase the RH, right? Well, remember that to cool the air, you have to blow it past something cold . . . and that cold thing will necessarily be below the dew point (if the air's at all humid), so voilà, the water condeses on the coil and drips away. So the air becomes drier. Not as dry as heating it, but drier.

Stuart

Side note 2: Brad's quite right. The Irish language borrowed both session and crack from English. I personally can live with the Gaelic spelling, but oooooh do I hate it when folks try to sound Irish and say something like "seshYUNE" for session. We all CRACK jokes in English, and that's the original word.

dcopley · Post by **dcopley** » Wed Mar 24, 2004 7:43 am

sturob wrote: So, unless the Irish keep their flutes outside, they're subjected to the same environmental stresses as those in North America.

I suppose this question could be answered easily if we had some real data, such as accurate hygrometer readings from a few hundred houses in various parts of North America and the British Isles. Since we don't have data, we do the best we can with plausible arguments and anectodal experience, and it is no great surprise if we reach different conclusions.

I spent the first 26 years of my life in England, and my recollection of winters is that excessive indoor humidity was much more of a problem than dryness. I think that a good part of this was due to milder climate, but that different living habits also contributed. Indoor temperatures are generally kept lower in England and people wear more clothes to compensate. I don't know what temperature our house was, since we did not have a thermostat. The heating system was controlled by a timer, and was turned off overnight (quite typical). As you pointed out, lower temperatures mean higher humidity, other things being equal. I also remember that there were almost always clothes being dried somewhere in the house (electric clothes driers were not common), which added to the humidity. So it all contributed to a much more flute-friendly climate, though things are probable changing over there as people become more addicted to creature comforts.

I am convinced that in most of North America, some form of humidification is needed. If the room or house is not humidified, then a humidified container is a good option.

Dave Copley
Loveland, Ohio