Bag Pressure Problem

Uilleann Pipes
1

I have a chanter that plays very nicely - reed is strong but not too hard.

In bag 1 ( from a practice set) all is fine. The chanter requires 20in manometer pressure going up to 25in for top B and C.

In bag 2 (same maker with a main stock) I can barely get the 2nd 8ve (this is why I got the manometer out). At the point where I my shoulder is about to dislocate, I’m getting 25in of pressure at the chanter stock. At this physical arm pressure, bag 1 is off the scale on the manometer. I cannot blow bag 2 higher than 25 in however and wherever I squeeze.

The neck of bag 2 is not constricted; however the mainstock is fitted very close the point where the neck joins the bag, and pressure in the neck feels very much lower than in the main part of the bag.

I’ve tested both bags for air-tightness and the hard bag is actually the better of the two.

Anyone come across a similar problem

2

Simon, are you sure your posture, i.e. arm position with respect to the bag, is the same in the two cases?

Adding a mainstock usually changes the way you hold the bag, and if you are holding too near the neck or otherwise aren’t “gripping” the bag with enough leverage, you’ll feel that you’re working harder to achieve the same pressure.

The business about the mainstock tying on near the bag neck really should not affect the pressure, the flow rate is way too low for that unless there is actually an obstruction on the neck.

3

Bass bars take a bit of getting used to. Put a plug in the mainstock cup to check things. Maybe you’ve got a booger of seasoning in there, too. Run a stick through the chanter stock, don’t hack up the bag of course. Check the blowpipe valve too.