As far as oiling goes, I just got this in an email from a well known maker
"NEVER USE A VEGETABLE OIL ON YOUR BLACKWOOD FLUTE!!!
That’s the best way to kill it…
Only mineral oil."
Meanwhile the Olwell website says the opposite and suggests almond oil, which is what I have been using 
Flute maker opinions do vary on this. My first wooden flute was a keyless Windward in blackwood. The Windward web site says the following: “We recommend a synthetic hypo-allergenic food safe bore oil by Alisyn, NOT a semi-hardening oil, like almond oil, which congeals and spoils.” So that’s what I’ve been using, a generic bore oil for wooden wind instruments like clarinets sold by a local music store. I think it’s mostly mineral oil.
Frankly, there is so little take-up of oil on my three wooden flutes – all purchased used, two in blackwood and one in cocus – that I only bother to oil them twice a year, if that. Bore oiling would seem to be something more important when first breaking in a flute?
Another thing I do that was recommended on the Windward web site is occasional light waxing of the outer surface of my wooden flutes with cork wax. I think the idea was to preserve the finish, but it may also prevent too-fast drying of the outer layer of the wood if a sudden change in humidity is encountered.
It definitely does prevent that very dry look of the wood around the embouchure hole after enough playing, and may help to prevent cracking at that vulnerable point. I rub a tiny bit of cork wax around the embouchure hole after every playing or practice session. Currently I’m using D’Addario cork wax, a “natural” hypoallergenic wax that’s basically beeswax with some natural additives.
I’m with the anonymous maker. I did try other oils (including peanut oil earnestly recommended in one book - it proved useless and ghastly!) when I was getting going with making, but came back to using the oils the manufacturers of clarinets recommend. Almond oil was fashionable back in the baroque to romantic periods, but I’ve not seen any reasons to have confidence in it.
Not that I think this is an element in the split occuring in this flute. That looks like a seasoning fault to me. Often very hard to spot during the making process, and very annoying to find after putting all the work in! The kind of cracks that occur due to interior swelling from failure to swab or oil are very angry looking cracks. And this is a very unusual place for a crack to form anyway. A tenon is under compression, unlike a socket. But it’s at the end of the piece, where seasoning cracks occur. Look at the ends of your firewood for examples.
I’ve seen dozens of antiques, some with obvious signs of neglect; in many cases, there are no cracks, so I de-emphasize the processing of lumber (the seasoning) or the handling of the finished instruments. I’ve sent several loads of timber to the sawmill (not flutewood), and the growing patterns are obviously to blame for defects that appear “off the blade” and others that develop in the drying pile, months later. Problems come from knots, of course, and any side-growth (branching). By the time time the lumber reaches the maker, there’s no way to see that the top of the tree had been leaning, putting internal stresses on a lower section of wood; in the shop, more cutting results in more movement along every axis, ad infinitum. And what if the tree had sun on only one side; or better water or nutrition from only one lateral root? Or weather patterns over the decades, resulting in irregular growth rings? These can’t possibly shrink uniformly. Or do we really want the outer circumference to shrink less so it doesn’t make a gap? Maybe we need a minimum distance from the core (flatter growth rings).
On YouTube, you can see the painstaking effort in selecting spruce for piano soundboards. Much wood doesn’t make the cut! https://youtu.be/xFkYNdB0xJM
Carefully seasoning can do only so much, then we cull the herd. Blackwood billets come encased in wax, so more seasoning occurs in my hands than elsewhere. Still, some defects don’t show 'til later (musical time-bombs!), and I think that may be the case with your flute. I think it’s reasonable to ask for a replacement component. I’m confident that the maker will appreciate the opportunity to make it right with you.
Of course, don’t leave your blackwood fife on the dashboard of your car in the summer. Don’t store your fine flute near the radiator in winter. I’ve never been a fan of pinning because I understand that the wood is fighting itself, and a pin will only find a new “weakest link”. If I had to repair a crack in a fife, the worst type is the hairline crack. Before filling with superglue, I like to gouge-out a wide V, relieving stresses; doing so also increases the surface for adhesion and gives the filler-bead its own integrity.
So I’ve just come into possession of a new flute less than a week ago. I’ve been slowly playing it in and over the course of the past 6 days have played it for c. 1 hr in total. I found the flute a little bit breathy from the beginning and assumed it was an issue of getting used to the embouchure. After playing it today and wiping and breaking down, I noticed that there’s a crack in the barrel. At first I thought it was just wood grain but definitely appears to be a crack.
I’m not sure now what to do. Go back to the maker and ask to have it fixed? Ask for a new barrel? send it back and ask for a refund (it’s now my fourth keyed flute) and move on? get it fixed by a local woodwind repairer? I’m not sure what the done thing is.
Sorry to hear about that. Any respectable maker will have a warranty policy,so If I were you I’d talk to the maker first, and try to get the barrel replaced. If they won’t do it you can either ask for a refund (if you have another flute and/or are willing to wait to get a new one) or ask them to fix it (which might affect the potential resale value of the flute a bit, if you ever want to resell it). Of course if you don’t live in the same country as the maker, it can be a bit more complicated, but in any case I would talk to them first before taking the flute anywhere else.
I had an Olwell pratten barrel crack about four months in. Called Patrick who told me they hadn’t had a flute crack in two years. He was upset and accused me of ‘flute abuse.’ I sent him the flute and he found a flaw in the wood, which was responsible. They will replace the entire piece. Like me, you’ve won the lottery. I was afraid I would have to wear a scarlet ‘A’ for ‘flute abuser’!
Sorry to hear about that. A reputable maker will be able to repair it, although it may take a while. I’m still waiting for mine. The lore of Irish flute playing is full of great players with flutes held together with electrical tape or homemade repairs.
I know many people love wooden flutes and don;t have cracking problems but I’m sticking to more durable materials in the future.
Starting point, Jeggy, is to talk to the maker. I’m a maker, and that’s what I’d hope for.
It is quite possible that what you perceive to be a crack isn’t. Blackwood sometimes (not always!) has quite strongly marked lines that can look like cracks but actually go nowhere. It would be worth trying a “suck test” and see if you can detect leakage. And report the result of that test to the maker too!
A suck test on the barrel is quite easy, but potentially deceptive! Just take the barrel, put the palm of your hand over the bottom end and suck on the tuning slide end. You should be able to “pull a vacuum”. Suck, block your lips with your tongue, wait a few seconds, and pull away. Nice plop? If not, it fails. Practice on the head if you want. Cover the embouchure hole and suck on the tuning slide. Again, you should not be able to detect any leakage. And good to run it on other parts of the flute.*
But I warned “deceptive”. Sometimes a crack in the barrel only shows up when you have the LH section of the flute plugged in. The outward pressure of the LH top tenon opens the split in the barrel socket area.
So, if it passes step one (above), try this. Plug in the LH section, wet your LH fingers and cover the finger holes, and put the palm of your hand over the far end. (Wetting your finger tips cuts down the leakage through your finger print sworls. Yes, of course I’m being pernickety. I’m a flute maker!)
Now suck again. Again you should be able to “pull a vacuum”. If not, don’t assume it’s the alleged crack in the barrel, do the same test just on the LH section alone.
(You can see that we flute makers are innately suspicious characters. We have to be. The universe is stacked against us! Murphy’s Law applies. “Whatever can go wrong will.” But that’s OK, we’re still winning!)
Do feel free to run those tests and come back to us.
*If you run the suck test on sections of the flute with keys, also do a blow test. You want to prove that the springs are pressing hard enough to keep the pads seated.
Did I mention flute makers being suspicious?
Thank you all for the advice and encouragement. I have been in touch with the maker and have done some additional tests. I don’t think now the ‘breathy’ tone is due to the hairline crack in the barrel, just getting used to things i think in terms of embouchure, covering holes and not leaning on Eb key. I used the head and barrel on another flute body and had no issues, or fewer anyway. Also, the crack could not be seen on the inside of the barrel, though it’s hard to see clearly in there. I’ll try the tests you suggest Terry! In any case, the maker is happy to replace the barrel to be on the safe side
Sounds good, Jeggy. It might come down to a difference in embouchure approach - one thing you do learn over the years as a flute maker is that there is no “best flute”, there is the “best flute for you”, and you have to find it. Or adapt to what’s in front of you!
In an idle moment (hmmm, why do flute makers not get idle moments?), take a squiz at http://www.mcgee-flutes.com/Getting_the_hard_dark_tone.htm. Trying the experiments there might help you work out what works best on that flute.
But do always be suspicious of the hardware - even the best made flutes will play up at some point. So good to get into the habit of running the suck and blow tests from time to time. Any detectable leakage needs to be investigated and expunged!