Advice please…
I have reed with a weak and very flat and pathetic back D; C nat and C # also affected. Otherwise plays adequately.
Bridle adjustments have failed to improve the back D.
The reed does appear to be thicker than usual at the lips. Would some sanding to thin the lips be a possible solution?
Thanks!
Mike
Hi Mike
I have made many reeds so I will pass on what I would do in your case:
First the weak back D is a real worry and may be a chanter issue. Check for leaks on the side of the reeds or just rub some wax crayon on the sides to be sure. That said I always tune a reed starting with the back D so I would move the reed down in the reed bed until the back D was around 440 then check the bottom D if sharp I trim about .33mm of the reed lips, at this time I am more interested in the e,f,g as the D tends to being a bit sharp. I then mess around with the bridle opening of the reed lips and the lip thickness.
From there I would have to hear what was going on with the chanter and which parts of the scrape to tweek. Its a minefield.
So before messing around have a back up reed
I am sure you will be inundated with hows an whys Best of luck 
Bryan
Update…
I trimmed a hair off the lip and sanded a tad, then move the bridle up higher to open the lips more.
The back D is now entirely adequate and it will play in tune throughout the scale, up to high D.
However, it takes a lot of pressure to play, making it uncomfortable.
I can back off the bridle, closing the lips more, which makes it easier to play as far as required pressure, however with the closing of the lips the back D is lost ( becomes weak and flattens).
Suggestions?
Mike
What I would do in this situation Mike,
is to remove a very small amount of cane from the area just inside the scrape edges. For this I use a very very sharp curved blade, ( a No.22 Scalpel blade ) but any sharp tool that can be used to remove a narrow strip of material along the edges of the scrape. Not to make the scrape shape any wider, stay inside the change over from scrape area to cane bark surface.
To refine this comment; firstly look at your reed carefully and see if it has been made in a balanced way, from side to side. I find that when I make reeds I tend to have the left side of the scrape thinner than the right (when holding the reed upright)… so I might scrape a little more on the right edges.
I also use a strong light ’ (as in a desk lamp) so as to ‘see’ through the reed head to try to determine if there are areas that look thicker / heavier. See the photo I put on face book this week.
I also press each face of the scrape gently against my thumb nail to try to determine if both sides have the same strength.
The thinnest parts of my reeds are the top corners. So when using a sharp tool to remove wood at the bondaries of the scrape by scraping I like to keep the width of that removed shaving to not more than 2mm.
Taking this measure very slowly a little at a time… one scrape and test the reed.
So, to recap: 1. adjust your reed as you have described so that it plays fine but is too hard;
2. take a scrape with a sharp tool that can remove material not more than a couple of milimeters wide all along the edges of the scrape area from front to back… tiny amounts mind you!!!
3. Test for pressure improvements.
I do this not by putting the reed back in the chanter after every tiny scrape and playing a bit , but by drawing air through the reed by sucking on the staple end , very gently commencing to ‘feel’ for the point when the reed begins to speak. It should be possible to determine if your work has made any difference.
I call this easing of the pressure needed to blow the reed “Oiling the Hinges”… just taking a little of the strength out of the head. If you can do this without going near the centre of the scrape it should be possible to make the reed demand less pressure without going out of tune.
Well that is what I do… you may have different results.. Good luck.