I don't like to give up saddle height unless I absolutely have to.
AGREE 100%
I would check your neck relief before doing anything more drastic. Try tightening the truss rod 1/4 turn to the right (you should have a truss rood wrench in the case pocket). If you get string buzz, you have tightened too much. IF the action is still too high, try another 1/4 turn until you hit the sweet spot.
I agree I've tweaked my "action" very slightly via the russ rod but I don't think you'll get even a full 1/64" that way.
I would also switch to light strings, which are the proper specification for the F-30.
The reason that I put medium gauge is that, considering I need to be one full tone below standard for vocal reasons (I cannot sing The Boxer at concert pitch for example), I wanted to eliminate fret buzz. I still have some but can manage with that.
Is it a problem to have this configuration with the F30? I thought that it would give similar tension than lights with standard tuning.
While I understand and am sympathetic to the idea, the lowered mediums may still have too much tension. There are charts, on D'Addario's site, for instance, showing what tensions are for both individual strings and full sets, but I don't remember if they show tension for strings dropped by a full tone.
Just make the test (straight edge was not easy to get). I am 2mm below bridge "corner". 5/64 inch.
Am I in the red zone you mention Tom?
What I'm thinking is possibly the top is thin enough to be deflected by the extra tension and this is also pulling the bridge towards the towards the headstock (causing the strightedge test to fall below the crown of the bridge). I wouldn't call that "the red zone", it might even have been built that way.
But yeah it would bum me out a little and it limits how much you can lower the saddle to fine tune the action to your personal preference, and not worry about the bridge.
If you can see a little "dip" between the bridge and the sound hole, that
might be a sign that string tension is too high, but a very slight dip can be normal. (Actually your pics look very good on that, it looks flat, but recently I've seen just how deceptive photos can be)
Another possibility is that somehow the bridge was actually raised slightly when your luthier re-glued it? I'd for sure ask him.
Also, didn't you get a UST intsalled? Ask him if it's possible the installation resulted in a slightly raised bridge height.
It's even possible the bridge was built a little bit tall. Then shaving a little bit is actually the ideal solution.
It will give you back saddle height to use with for lowering the action while keeping good break angle.
The bridge not only seats the saddle, but its mass affects how energy gets to the top. Too much mass is almost as bad as too little mass, and that's why shaving the bridge is generally avoided.
Also, it can lose structural integrity around the saddle slot. If it's too shallow the saddle can start to lean. If you deepen the slot, it could split. So shaving an already ideally sized bridge should be avoided.
I made a wrong measurement I think. From fret to bottom of string it is a little bit more than 2mm (probably 3/32 inch). I can now wonder if there is really an issue!
Sounds like you already realize that Guild's last published specs for action height were in fact 6/64" on bass E and 5/64ths on treble. 3/32=6/64.
There was a "tolerance" of .5/64th (
half a 64th, or 1/128th) and I always forget which way it went, but still, if you're at 5 and 6/64ths you're within 1/128" of factory setup specs. Some people do consider those specs to be "high" but it's good to know you're actually right where Guild built it.
If you don't have at least 1/8" saddle showing, you may not be able to lower it enough to make a difference
The rule of thumb is that the ideal
combined height of bridge and saddle is about 1/2". This allows the best transfer of energy from the strings into the top. The "ideal" saddle height of 1/8"' also creates a good "break angle" of the strings over the saddle. Again, the issue is energy transfer through the saddle to the bridge, then the bridge plate, into the top.
If your saddle is actually 5 or 6/16" tall that's not such a big deal. If it's lower, you want to have a serious discussion with you luthier about the pros and cons of a slight bridge shave.
It DOES sound like right now you have what is called a "shallow neck set", but I'd be pretty surprised if it's in need of a reset already.
I suspect it was built that way, it happens. But it might be slightly aggravated by the medium strings.