Glue back cracks and braces at the same time or seperately?

[downtime]

I recently acquired a Harmony H-162 as a project guitar to practice repair skills.
I plan on doing a neck reset, bridge re-glue and crack and brace gluing.

It has a significant back crack (2 cracks actually) along with 3 loose back braces under the cracks. With outward pressure from the braces below and squeezing the sides the cracks do close up.

It seems to me that attempting to get glue in the cracks and under the 3 braces and then get everything aligned, cauled, jacked and clamped at the same time might be a tricky situation. I also intended to use hide glue and I'm worried about how much working time I would have.

Does it make more sense to do this in 2 steps by gluing the back cracks first and then prepping and gluing the back braces?
The issue I see with the 2 step approach is that squeeze out from the crack repair will adhere to the back braces.

Alternatively I could just use titebond original with a longer working time and try to glue it all at once.

As far as clamping, my plan is to use brace jacks and wedges on the interior bracing, a long caul on the top and bottom with clamps and then surgical tubing around the body to pull the cracks together sideways.

Any advice would be appreciated.

Here are a couple photos of the cracks:

[redir]

There is nothing wrong with doing them at the same time if you can but because it's easier and sometimes not possible due to all the clamps I always glue the cracks shut first.

You can slip wax paper under the brace to protect it. Sometimes they stick a bit but if you are careful with your glue then you can usually just break it free with a pallet knife.

[downtime]

Originally Posted by redir

There is nothing wrong with doing them at the same time if you can but because it's easier and sometimes not possible due to all the clamps I always glue the cracks shut first.

You can slip wax paper under the brace to protect it. Sometimes they stick a bit but if you are careful with your glue then you can usually just break it free with a pallet knife.

Thanks redir,
I was thinking about using wax paper, I think I'll go that route.

Is hide glue your preferred adhesive for this type of repair?

[Piercast]

Originally Posted by redir

There is nothing wrong with doing them at the same time if you can but because it's easier and sometimes not possible due to all the clamps I always glue the cracks shut first.

You can slip wax paper under the brace to protect it. Sometimes they stick a bit but if you are careful with your glue then you can usually just break it free with a pallet knife.

^^This.

The cracks look really wide though. Not sure they’ll be willing to close easily. Try humidifying the guitar to 40-60% first. You may need to do splints on this one.

[redir]

Originally Posted by downtime

Thanks redir,
I was thinking about using wax paper, I think I'll go that route.

Is hide glue your preferred adhesive for this type of repair?

Yes I like to use HHG for such repairs. But Titebond is perfectly well suited for it.

BTW I would further say that when I have two cracks side by side like that I do one at a time THEN reglue the brace.

[Piercast]

Originally Posted by redir

Yes I like to use HHG for such repairs. But Titebond is perfectly well suited for it.

BTW I would further say that when I have two cracks side by side like that I do one at a time THEN reglue the brace.

Yep. One crack at a time is the way to go.

[downtime]

Thanks for the replies, I think I have an action plan now.

Would the braces be enough cross support for the crack or would it be wise to cleat in between the braces?

[mirwa]

I personally would remove the braces in the area inside compleltey, sometimes braces prevent areas from closing up nicely.

I like to deal with the issue and then rebuild the structure eg braces

Steve

[Piercast]

Originally Posted by downtime

Thanks for the replies, I think I have an action plan now.

Would the braces be enough cross support for the crack or would it be wise to cleat in between the braces?

As I said, not sure this huge crack will gracefully and without excessive force completely close or not, but it’ll definitely need cleating if it does.

[redir]

Some cleat some don't. I like to use cleats and those cracks certainly look long enough to warrant the use of them.

In fact one of the tricky parts about a repair like this is getting the two cracked halves aligned perfectly before you clamp them shut. I like to use tuning machine clamps with a cleat for this very reason. It pulls together and aligns the halves then I clamp the whole guitar shut.

Steve makes a good point about removing the braces, or part of it too. Do a dry run first and if the cracks do not close then you may have to consider doing that.

[downtime]

I've decided to let the guitar sit for a week or two to insure it is re-hydrated. I'll then do some dry runs cauling and clamping the back cracks and decide how to best get them glued up.

Thanks for all the input.

[redir]

I forgot to mention that a lot of luthiers use magnets for the same reason, to align the two halves of the crack. But you need to get those really powerful magnets and they are expensive and sometimes fly across the work bench and stick to your vice or something

[difalkner]

Originally Posted by downtime

Thanks redir,
I was thinking about using wax paper, I think I'll go that route.

I have found that parchment paper works far, far better than wax paper. Glue will work its way through wax paper but does not through parchment paper. In my general woodworking that I do every day I have pieces of parchment paper that I've been using for years.

Let any glue dry completely on the parchment paper and then you can just pop it off and reuse the paper. If you wipe it while it's wet then it's difficult to remove, so just let it dry thick and in drops.

[redir]

As a matter of fact I also use parchment paper but have a bad habit of calling it wax paper. Good point David.

[downtime]

Originally Posted by redir

I forgot to mention that a lot of luthiers use magnets for the same reason, to align the two halves of the crack. But you need to get those really powerful magnets and they are expensive and sometimes fly across the work bench and stick to your vice or something

I have some rare earth magnets that I've successfully used for other minor crack repairs. I may use them in this repair, especially on the smaller crack which I will likely glue up first.