Is your pipe bag leaking air?

The pipe bag is one of the most likely areas to leak air.  Any air lost through the bag is air that you have to replace, making it harder to play.

Regardless of the bag material, it must be airtight.  To check this, plug the chanter and drone stocks with rubber stoppers. Blow up the bag until it is as full as it can get, the squeeze it for 30 seconds. If after 30 seconds, it takes more than 1 breath to fill the bag, it is losing too much air. 

Common sources for leaks are the seams, around the stocks, or the stocks themselves.  If you can't hear or feel the leak, use a soapy water solution to check.  If the leaks are through the seam on a hide bag, a good seasoning may correct it.  If the leaks are through the seam on a synthetic bag, it likely needs replacing.  Re-tie in the stock for leaks around the stocks on a hide bag.  On a synthetic bag, if the leak is between the rubber grommet and the bag, it will have to be replaced.  If the leak is between the stock and grommet, you can wrap some plumber's tape around the stock at the top of the grommet, or remove the stock and build up the diameter at the tie in groove with the tape.  If the leak is through the stock, there is a crack in the wood. These cracks are most common underneath the stock ferrules, but can also occur lower down. If this is the case, you will need to have the stock repaired by a bagpipe maker/repairer.