Four years ago I put Bill Miller premounted skin heads on three banjos. It was winter in the Midwest, meaning dry, heated indoor air. I tensioned them to what I thought was a reasonable tightness and never touched them again. I let them sag in the humid summers and enjoyed the plunkier sound, and let them tighten up in the winters and enjoyed the crisper ring. (I did check them nearly daily during winter with simple thumb-pressure, but never thought they were getting dangerously tight.)
Tuesday I discovered the head on the 12-inch pot had split. Of all the banjos, this head has always been the loosest, even in the winter. I've periodically considered snugging it up, but the large pot is naturally plunky anyway, so figured the looser tension just added to the flavor.
We've periodically had the air conditioning on for a few days, but this summer has been unseasonably cool, so mostly the windows are open. The split happened during an extended period of cool temperatures (day time highs in the 70s) and humidity hovering around 50-55 percent.
So my question for the bright minds in this group is: should i dash to loosen the heads on the other banjos? Or was this likely a one-off occurence caused by some inherent weak spot in this particular skin?
Because the split is in the middle of the head, the conditions were not extreme and the tension was not excessive, I expect it might have been a natural weakness that eventually just gave way. Most of the tension-related breaks that I've personally seen occur at a stress point ie: around flesh hoop or where the hide contacts the tension hoop.
Most hides are very reliable. Many last for decades with relative stability and no problems. Others may indeed break from too much tension or extreme conditions. But sometimes they just break for no obvious reason. I think that is to be expected with a natural organic material.
I don't have empirical proof, but my opinion is that bleached hides are weakened by the chemicals used to make them white. I say this simply because in my own personal experience, the only ones I've broken were bleached white skins. Like you, I just found them split one day for no apparent reason.
I'd recommend you re-mount an un-bleached natural hide...and not too thin. I prefer them to be .012in - .014 in. thick for high-grade calf, and a little thicker for goat.
Until recently, all my banjos had skin heads, then one split for no apparent reason at all. When I changed the head, the guy told me that he could find no explanation for it. I had him put on a Fyber3, so I would have one synthetic head to take outside in high humidity and raining conditions. Unless you had a sharp edge somewhere, I doubt you'll ever know. Like everyone said, it probably was just a weak spot in the wrong place at the wrong time. Good luck.
all my banjos have skin heads... never had a problem with any of them.... and one is ~100 years old. the split area points towards a natural weak spot in my opinion... i'd trust the dudes who posted above me more though!
Thanks to all for the input. You've confirmed what I suspected -- a one-off occurrence based on an invisible weakness in the head. I'll take John's advice and replace it with an unbleached head. I prefer the look of unbleached skin anyway. So maybe this was just a good excuse to change the head.
I enjoyed Mr. Miller's heads but both of mine split in humid(Hawaiian) weather. However my heads from John Balch never had a problem no matter how tight I cranked them down. I recommend one of his heads for replacement.
One more thing: personally, I do adjust the tension of my heads in response to changing conditions. I live in the central basin of Tennessee (John Hartford called it "the bathtub of the south"). Our humidity ranges from near 100% in the summer to below 20% in heated homes during the winter. I adjust my hide heads for sound - as needed. In humid conditions, I may tighten a little. In the very DRY winter, I loosen. These adjustments are always motivated my the sound of the banjo. I make very small adjustments - if the sound dictates. It is really no more hassle than tuning the banjo.
I probably maintain a lower overall tension than some folks - but that is my preference - again based on sound.
My adjustments are are usually made -on the fly- without tools or special techniques. Again - it is like tuning the banjo - by ear. I just do it as needed. But for initial set-up or to explain my thoughts to others, I developed the attached instructions and images. These are not hard-and-fast rules. But they help me achieve and maintain the tone I prefer from my banjos. Hope they are useful for you.
My skin head just opened up also. Maybe it's a midwest thing. Mine might have been more extreme in weather conditions also. It had been in Tucson AZ until this May to the fairly humid, but fluctuating humidity of Lansing MI. It cracked around the upper part of the tension hoop on a White Ladye. I had tightened the head, but slightly, when I got back to Michigan. I took it to Elderly and the technician was surprised, primarily because you could expect it more if the trip was from Michigan to AZ. They are putting a new skin head on and I will keep you posted. I'll likely watch my tension more carefully in the future.
