Pre-Radius

[hummingbird]

I am about to start my first guitar. please forgive me if this question/idea sounds stupid.

I was thinking about what the experts always say about not wanting a joint to be under stress and that the guitar will sound better if the joints are relaxed and not forced together when glued.
However, when we glue on the braces, the top and back are forced into a radius dish to conform to the contour required.

I was thinking that before I glue my braces on I will "Pre-Radius" the top and back by placing them into the radius dish with weight on them for a week or so, perhaps with some heat or steam at some point. After a while they should in theory take on the contour shape without force. Then when I glue the braces on, the whole assembly should fit together with very little stress.

Not sure if that would make any difference at all but I thought I would put it out there. Any thoughts?

[David L]

Hey Levon,
Yeah, what Tony said plus consider that you have four very sturdy braces that span the entire width of the back not to mention the center strip brace that backs up the whole length of the joint. I like the way you think (others may not), at least it shows that you're putting a lot of thought into this. Glad to see you getting started. BTW, whatcha buildin'? or did I miss that in another thread?

My 2 cents, but hey Tony, my 2 cents are worth 3 cents Canadian

David L

[tippie53]

agree as when you brace it , the stresses will build by the change in RH . Don't sweat it , you will do find

[kencierp]

This is not a recommendation -- however, its something I pick up from the David Russell Young publication -- right or wrong before brace gluing I have always heated the inside surface of the top and back plates either by holding it in direct sunlight for a few minutes or using a blow dryer --- the plate will curl/cup nicely, like I said very quickly -- of course what is happening is the moisture on the heated side is evaporating causing that side to shrink -- no doubt over doing it can make a mess.

[hummingbird]

Thanks alot guys.

Having not yet seen the wood or dish I'm merely speculating.
What you are all saying makes sense and I thank you for your input.

I got a couple of "practice kits" that Jim Hall put together for me
From spare stuff he had kicking around in his shop. A Martin dred and a OOO. I'm going to start with the dred. Should be on my doorstep any day now. :)

[Ben-Had]

This is not a recommendation -- however, its something I pick up from the David Russell Young publication -- right or wrong before brace gluing I have always heated the inside surface of the top and back plates either by holding it in direct sunlight for a few minutes or using a blow dryer --- the plate will curl/cup nicely, like I said very quickly -- of course what is happening is the moisture on the heated side is evaporating causing that side to shrink -- no doubt over doing it can make a mess.

I did that once on a top but I used the inside of my car on a hot summer day. Good thing the curl came out the right way.

Tim B

[tippie53]

there are those that go as far as baking tops. I do use a heating blanket that heats the back and top to about 180 degrees for 15 minutes . this does get the surface moisture out and since I have been doing this I have not had any crack issues and have seen the plates to be more stable .
I can't say that there is any scientific information on this but in reality if the top is dryer than the surrounding air you won't see as much problem from the water infusion of fresh glue .