EXTRA BRACE?

[Lex]

Starting new thread on the 58 Gibson. This is the one where the neck collapsed into the sound hole.

I feel things are going well. All but one brace have been removed and glued. cracks are filled. My question is.... Do I need to put an extra brace between the neck block and the first brace?

If yes, what length, thickness and width should it be?

Thanks

Lex

[Taffy Evans]

G'day Lex, ok, a series of photos that may offer some ideas you can apply to your project, these worked for me in these instances and there are quite a few other ways one has to come up with to suit different situations.

Remember whatever you use as props on the inside do a dry run first to see if i/they can be removed or repositioned through the soundhole after the body is boxed up.

Use the brace ends as a way to push the sides into position.

Use the neck as a lever to align the neck block into the correct position to give the correct set of neck angle. Then find a way to keep it there.

I would glue the back on in one operation normally, But ya gotta do what ya gotta do, you are there, I'm not. Ok, the photos.

Spreader in use to aid positioning of braces...

Here is an idea for spreaders to help line up sides...

This is a top of course but I'm showing how the braces on the back could help push the side into alignment...
A top again but showing how I repositioned the neck and held it there..Before I started the disassembly I made this form...

[Lex]

Taffy, when I place a straight edge on the neck which has an under bow to it the straight edge is 3mm above the bridge. I will post a photo. The back is still off. I feel the string tension will bring it down. Should I place a shim with a bar from the neck to keep it there or what while gluing back? Maybe I need to adjust neck to straight firstly?
Lex

[Lex]

here is the pic

[Taffy Evans]

Hi again, normally a straightedge along the fingerboard would just touch the top of a bridge, assuming the bridge is at the correct original height. 

If the neck is bowed then that is another job.

You could place the back in position with the tail end flush with the sides, and clamp it there.

At the heel end, there may be a misalignment of the back and sides.

Move the neck so as to position the sides [at the heel] with the edge of the back.

Caution - this will possibly move the sides in or outwards somewhat, depending on which way you moved the heel bock end.

Now check the projection of the neck to the bridge.

To aid in the back maintaining that position during the gluing process cut two spacers to fit between the neck block and the nearest back cross brace. and the same tail block 

Fit these to the back with tape for removal through the soundhole when the job is done. Check their removability prior to gluing up.

I rarely find it possible to plan too far ahead with jobs like this, as one task can lead to another that was not thought of, or the first plan gets modified or abandoned. 

Hope this helps, good luck. With your neck issues, there are plenty of videos online to help you.

Cheers Taff

[Lex]

Hi Taffy, Finally got the courage to glue back on. Had help with two of my sons. I don't think it could've gone any better. very little trimming to do after it was dry. the original binding appears it will go back on with no problems. Question... what glue do you recommend to put it back?

The neck angle I think is good it is 3/4 mm above bridge.. your thoughts?

The bridge is only held in place by the screws at this point. how can I intonate before gluing it?

You have been a great help!!!!!

Lex

[Taffy Evans]

Hi Lex, if your neck is in its original position the bridge would go back into its original position.
So let's assume things are a bit out.
In the photo, you can see how I do it on a new guitar. The two strings are at the correct height and tension. I pluck a string and move the bridge until the tuner reads the correct note when open and fretted at the 12th fret.

Don't forget any movement of the bridge may mean the filling and relocation of the bridge pin holes in the top.

I suppose the safest bet for gluing plastic binding would be Stewmac's Bond-All binding glue.
Cheers Taff

[Lex]

I tried to post pics with last post but I think they were too big. so hopefully here they are.

did you make that tail piece? is it anchored to the strap pin? how did you make it?

Thanks

Lex

[Taffy Evans]

Hi Lex, photos look good. 

The tailpiece is an old one I found around the shop, fitted the to endpin by a zip tie. I don't think you would have one, so, what I do at times like this is look at the part I need, understand its intended function, then see what I have on hand that can replicate it. keeps the brain active haha.

Ok,  ok, I give you a clue to get you started. A small door hing for starters or look at a violin tailpiece fitting. Good luck.

Taff

[Roger Häggström]

There will be a big difference in intonation result on wound strings using string pins or a tailpiece. With a tailpiece the intonation angle will be 1-2 mm less than using string pins, measuring intonation with a tailpiece on a pin bridge is not recommended.

The reason for this is the much steeper break angle using string pins. The part of the wound string just in front of the saddle will be very stiff, the wounded string on the underside of the string will be compacted, and in fact make the vibrating part of the string shorter. The saddle has to be moved back 1-2 mm closer to the string pin for correct intonation.

[Lex]

I think I’m going to trust that Gibson put it in the right place at the factory and just glue it back. Like putting the back on it may take me some thought for a couple weeks before I’m brave enough to do it Ha!
Thanks guy’s
Lex

[Taffy Evans]

Hi Lex, if you do not wish to use my method that's fine, you could use measurements.

Plot the scale length, then as ballpark measurements, use the following as compensation guidelines.

All are subject to string height, string gauge, and scale length, but I would think it will let you judge how far out the bridge is, if at all.

1st add- 1.49mm  and 6th add - 4.79.

I have used the method mentioned above for more years than I can remember, and my finished guitars have no problems with intonation. 

Taff

 

[Roger Häggström]

I used to use the same method with a tailpiece for many years, but the intonation measures were never spot on. I learned to move the saddle on the bass side a bit closer to the string pins and make the saddle thicker to be able to find the intonation spots using the string pins. Most of the time the end result was good, but the inaccurate measurements kept on bugging me until I started to intonate using string pins and finally got measures I could trust, making it possible to have a thinner saddle.