I’ve just finished tying the unscraped head onto the staple and cannot stop the blades from separating along the length of the head. I use standard measurements according to the likes of Hegarty and also David Quinn’s manual and I gouge the tail where the staple lies.
I don’t always have this problem, but it is a common occurrence and I was wondering if anyone could provide some insight into why this happens and what I can do to prevent it in future. Should I try NOT gouging the staple bed?
David,
My first thought would be that the corners of your tail/shoulder is too wide/too sharp, and that the tail is too wide. Also it could be that the staple is hammered too flat
The pic showas R > L.
Too wide tail, too sharp corners (basically just cut, unshaped and unsanded.
tails shaped
3.Corners sanded.
That’s how I do it, anyway, there’s loads of ways of flaying a cat, mine is with a stanley knife and sand paper…
Could also be that you are making the 2nd gouge too deep?
Hi Alan and thanks for the detailed reply complete with pics
My tails did look like the one you did, ie not too sharp or wide plus chamferred and all that.
By 2nd gouge, do you mean when gouging the tails for the staple? I may have done it too deep. The staples don’t seem too flat but I’ll see how I go with the head design first before trying to change staple dimensions. I’ve used these staples before no problems so I’m guessing it’s in the head/tail/gouging itself.
I think it can go both ways, if you have no 2nd gouge (at least with the former I use to impart curvature to the slip) you end up with leaks/gaps if not careful and with a 2nd gouge (yup, the one down the tail) too deep, then the gap business occurs again. shrug Try to note how gap forms, from the centre of the sides or from the tips, I tend to think that gaps opening from the tip are often more staple problems than cane. When I gouge the tails, I gouge anything between 10 -15 mm from the centre point of the slip (if your slip is 100mm, then gouge will be 35 - 40mm long), I guess I’m trying to remove about 0.5mm in depth, so if you have a slip at 1.5mm, then your tail will end up 1mm at the tail tip. G’luck!
To echo Alan, if the width is “too” wide relative to the length of the tails, you end up with a fulcrum effect when you tie down the tails to the staple. Rounding the corners often solves this (at the expense of decreasing the internal volume of the reed).
Secondly, often you will bind quite tight at the point of the tails, but relax the pressure as you bind up. If the staple is positioned in the tails so that the tail tips are noticably far away from the staple, you end up with the fulcrum effect again. Foregoing the gouging of the tails can solve this problem, depending on the staple. This gouging is meant to clear the way for the staple (although any gouging that extends into the head of the reed can have tuning implications). ***
Related to this is the pressure of binding as you go up. I believe it was Paddy Keenan who pointed out to me that if you are careful to pull across the flat side of the reed (not against the edges) you can pull quite hard.
Last, but definitely not least, is that the slip may not be even along its edges. That is, the sides may not be perfectly parallel to each other, and/or the thickness along the edge may vary.
Eric
*** this gouging will also reduce the “smooshing” of the lip end of the reed. These are the kind of things that make you have to use the bridle to produce a mechanically and dimensionally correct reed. Better to try for shapeliness from the outset, and save the bridle for small adjustments.
I’ll go and have another crack at it. Thanks for the advice. (I should actually go and do some work on my dissertation, but hey…what’s more important ?
Thanks for the tips Eric. The last point I don’t think was my problem as I had carefully seen to it that the edges were nicely parallel and even and all that. My brand new callipers helped see to that. What ever did I do without them??
This may sound silly, but human fingers can be very sensitive instruments for picking up bumps and unevenness in slips. Also, holding the slip up to a light can reveal patches of thickness (it gets darker)***. It’s worth musing over your slips in this way, even when you use calipers, because it helps develop a sensitivity to the little buggers.
And regarding sensitivity to reeds, it is worth pointing out that dimensions found in manuals on reed making are only an approximation. Paying close attention to the relationship of volume to length, as well as mechanical soundness, can help you tweak your reeds.
*** although Arundo Donax being what it is, it can be even on the interior but vary relative to the bark side. Something to watch out for when using calipers.
You’re spot on with regards using fingers to feel for evenness. I’ve been making reeds (on and off) since I started piping ten years ago and only now just acquired callipers. Until now I’ve just relied on my fingers to do the feeling. So actually, perhaps I should avoid becoming too reliant on the callipers. I’ve not had much pratice at reed making because, well, I’ve only had to change reeds about 5 times over the past ten years and so haven’t really gotten into the make-a-reed-a-day thing. That’s why every two years or so, when I do get back into it I need to drag out all my books, blow the dust off the gouge, wander around the house trying to find where I stored my cane and find advice occassionally on how to fix glitches such as this one.
I presume you mean sharp corners vs rounded corners?? The advantage to rounding the corners is that it increases the pressure at the edges up toward the lips.
A side effect is potentially decreasing the volume relative to the length, which may flatten notes in the second octave.
You round the corners after cutting the slip in half and binding the halves together by rubbing the corners on a piece of sand paper lying flat on the table. in a rocking motion. (Note that the tails are typically scalloped in a bit at the sides before rounding the corners, rather than being left straight; this lets you bind harder where the tails meet the staple and evens out the pressure along the edges).
I haven’t read them yet, but I was there in West Virginia during these sessions. Furthermore, Benedict is THE reed guy, bar none.
So, I suspect they are worth reviewing before you proceed.
… I just scanned over the “Scraping and Sanding the Head” section" definitely some important finer points in there.
I also just took a quick flyby on reed web sites and found the guidebooks on the following two pages to be usefully detailed in discussing tricks for tuning:
Not sure if what we have up will be of much use with all the finer points of reed making at this point (hopefully to be remedied soon however!) but you can take a look and see if our reed making page offers any additional insight as to shape etc.
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