Gibson J55 Top Crack Repair Advice

[RETROROD]

I just got in a '73 J55 with a  top

crack along the pickguard extending North and South of the soundhole. I think it can be glued and cleated fairly well, but I would like some advice please.

The treble edge of the soundboard has curled up about 1/8' from the rest of the top. It takes quite a bit of pressure to try and match the edges. Should I humidify some to relax the top before glueing and splinting?

The crack extends north beside the fingerboard and south along the pickguard almost to the bridge.

This is a "classic" Norlin Gibson. Double X-over-,braced example. Also their first year of the arched-back dreadnought..It also has the 'tortoise binding' which is starting to disenegrate....Jeesh!

 

I have taken many pics in the afternoon sunlight and will provide some for clarification.

Rod

[RETROROD]

Here are some more pics....

[Andrew]

Im thinking this is being caused by the pickguard shrinking. Remove that first and see what kind of pressure it takes to level the crack. If its still to much, Id make a caul to fit around the braces inside and a flat one on the outside, and give it a wipe down with a warm damp cloth, then clamp it flat, or as close as you can safely get it. If that brought it closer Id repeat until satisfied, glue with hhg and cleat. Then deal with regluing the pickguard.

Where on the body is that damaged binding btw?

Id also be tempted to give that bridge plate some attention.

[RETROROD]

Thanks Andrew, That particular binding damage is on the bass-side waist. There is another area that is starting to separate where the forearm would lay. There are several more l(every few inches) 'crystallizing' areas around top and back binding. These spots are very much like the de-composing pickguards of some guitars.

I would say that the two areas pictured are the worst as fas as the binding cracking or separating from the body. Probably a "time bomb" at best!

[Paul Verticchio]

Hi Rod,

Good advice from Andrew to remove the pickguard before doing anything else.

The crack extending along side the FB over the body COULD indicate a cracked or shifted neck block. I'd wait to hear from some of our very accomplished acoustic guitar surgeons on here before humidifying or doing any gluing or clamping.

The guitar is otherwise in GREAT shape for a '73. She's definitely a 'great looker'! Best of luck with getting her voice back for her. :)

Have a good one, man :)

[Andrew]

Yeah checking the neck block would be a good idea. That was my first reaction until I saw the continuation of the crack below the soundhole, following the pickguard. Still shoulda mentioned that though.

[RETROROD]

Andrew, I think that you are right about the pickguard 'drawing up' the wood. It is a thinner material than the '60,s  thick guards. It is stuck down well also!

Paul, I'm like you....the guitar is a 'looker' and possibly a 'player' as evidenced by the ruts in the fingerboard! I can,t wait to hear it...

Rod

[Andrew]

Will you be replacing the binding as well?

[RETROROD]

No, not at this time. I am to just repair the crack. Any ideas on 'stabilizing' the cracked areas though??

[Andrew]

Im recalling Dan Erlewine's method of consolidating celluloid tuner buttons with CA. But I dont think I'd want to be doing that with this binding. Other than that, I got nothin lol.

[Ned Knepp]

I don't know of you remember or not but we had a discussion about celluloid pick guards on here a while back and the general opinion was that once the out gassing starts on celluloid it's a cancer that continues to spread. I don't remember anyone  having a way to reincorporate the plastic to repair it. 

In what have been able to find about restoring old film it appears that the major issue is that camphor is one of the things that is out gassing and there doesn't seem to be a good way to replace it. I'm sure you can glue the cracks up with CA but the non- CA portion will just continue to degrade and it will continue to spread to more and more of the binding. 

 If it were me, I'd figure on replacing the binding  instead of  putting it off too long. Any areas you CA into place will just be that much harder to remove when you do it  Maybe you can match up new binding with a new pickguard  and make it much harder to tell that it's new.

[Hesh Breakstone]

Rod buddy here is how I would get to this one:

1)  Remove pickguard for better access to the thing and so that the guard is not in the way of the flat cauls that will be used to glue the crack back together level.

2)  Bag it!  More specifially we want to see how much the cracks will close with rehuidification.  So hang it from it's headstock and put a large, Hefty type garbage bag over it coming in from the bottom.  The bag will have a large car wash type sponge in it with about 8 ounces of water that will sit in the sponge and in the bottom of the bag.  Leave it for one week before opening it up and checking for crack closure progress.  This will raise the humidity for the instrument to about 75%.

3)  Wash hands - seriously, now we will start fixing the crack and cracks like to take the dirt fron our fingers and embed it in the cracks.  Glue them back dirty and you have just encased the dirt for the rest of time and it will show too.

4)  Make a tongue shim which is not a marital aid but a shim made out of perhaps mahogany, spruce, or maple with the grain running at 90 degrees to the neck direction.  This shim gets glued under the tongue spaning the crack on the treble side and butted against a brace, perhaps the UTB, and the side sound hole supports.  If done well it will not show.

5)  Often cracks that have been open for a while will not close all of the way with humidification.  If it does close rub in glue with those clean hands and manipulate the crack to get the glue to show on the underside too and this way you know you have used enough glue and have full coverage.  Titebond original is fine for all of this.  HHG works too of course.

6)  Clamp with rare earth magnets, the 3/4" ones that provide about 40 pounds of clamping pressure per square inch.  Be careful these high-powered magnets can bite ya if not careful.

7)  When using the magnets use flat cauls such as clear plastic sheet that is about 1/8" thick and with the edges safed so as to not scratch the instrument.  Use waxed paper under the caul and in direct contact with the guitar top.

8)  Once glue has been rubbed in to the crack(s) and they are firmly clamped level and flat let it dry at least a day.

9)  Install cleats where the tongue shim is not and Bob's your uncle!  Use hot water to clean up any glue residue that shows.

10)  If the crack will not close on it's own with humidification they you will have to fill it.

Hope this helps!

[RETROROD]

Thanks Hesh, a lot of good info!      that helps immensely. It sounds like a good plan to me.

Rod