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Let me just add this
Many ways to do things
I've glued on 13 bridges using the fox clamp.
Never had an issue, always plenty of time to work with titebond. Haven't seen one fail yet
It is getting harder for me to reach in and screw on the wing nuts but that's a big hand old age thing

tippie53 wrote: ↑Wed Jul 13, 2022 3:29 pm let me explain something
these bridge clamps are ok but they assume all bridges are the same Few allow for tapered pin holes the few that have a small caul under the bridge plate allow top flexing and can distort the top. I have them even designed one and went back to 3 6 in deep throat clamps.
May caul fits under the top , goes over the braces and allows for the bridge plate so you don't have to worry about over torquing the top.
It is easy to warp the top with these so be carful.

Thanks for taking the time to explain why you prefer using regular sound hole clamps and a caul vs. a bridge clamp. I understand that in your experience that the small bridge plate caul on these things can cause some flex/distortion of the top with some bridges. Seems like others haven't had an issue. Maybe it's because of the bridges they use.

Anyway....As I said before, I am considering using 3 cam clamps and a caul. My caul doesn't go over the x braces but I checked and my bridge barely extends ( just the very corners of the bridge ) beyond the x braces so I think it will be OK.

Thanks again for the help.

Scamp

If you use clamps you need a solid flat area inside for the clamp to reside on for good clamping pressure especially out on the wings of your bridge. Thus a caul that will straddle the braces. I do it this way on classical guitars because no bridge pin holes used on a classical of course.

The very corners of the bridge wings is at issue. They're the first thing to pull up when not clamped.

Thanks. If I use clamps I will make a better caul that straddles the braces. Good input.

Question for my own intellectual curiosity.

The guitar top has a radius to it ( 28 degrees ).
The bridge caul behind the bridge doesn't have a radius to it as it is flat.

So... It would seem to me that the the bridge caul under pressure would tend to flatten out the guitar top.

If the back of the bridge matched the radius of top ( by sanding down the back of the bridge a bit as suggested by Bill Cory in his book ) the caul, being flat, wouldn't apply even pressure to the bridge and top. It would tend to apply more pressure to the ends of the bridge and it would tend to bend both the bridge and top down flat to the caul.

So.. my question, does this happen? If it does, does the top just tend to bend back to the original radius with the bridge? Just wondering.

Scamp

Ah hah
Now you know WHY I use the fox style clamp.
The bridge bottom fits the top contour. The clamp pushes the wings down enough to make good contact and get some glue squeeze out. Always had a kerfect glue up with
no top distortion....or if any, negligible.

Forcing a standard belly style bridge to the 28 ft radius of the top with whatever style clamps is what I used to do long ago. Getting a 6" bridge to have complete contact all around as a prerequisite before gluing and clamping is my goal. Using clamping pressure alone to mate wood surfaces always risks them wanting to separate. I use clamps to get comparable all-around squeeze out/firm contact. I have used the caul with tightening knobs for the wings, but even there unopposed pressure can in theory deform the top in a small way. Mostly I use 3-4 cam or purpose made clamps, lots of Titebond or HG and start with a good dry wood fitting.

I do them flat just like Martin I have found that the radius can crack the top when the RH drops

I don't radius the back of my bridges. Yes, the top has a 28' radius, but the radius isn't horribly steep. I've never had a problem thoroughly gluing a bridge to the guitar and I have no failures. That's why it's important to caul the bridge wings. Glue is stronger than wood. Everything will conform.