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I have a brace repair to do on an x-brace. I would like to use HHG. I have a 1 x 7 heating blanket. I was thinking about clipping the heating blanket to the brace with clothes pins to heat the brace and then work some HHG in. Will the heat damage the finish on the top? Also, what would be best way to work in the HHG before it sets? Thanks.

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No experience here, but anxious to hear replies. Seems to me that heat like this inside the box could have the whole thing come apart.

Considering how difficult it is do undo any joint cleanly, HHG or otherwise, I wouldn't worry too much about the other joints, or the finish.

However, why do you want to use HHG? Unless you're very good and very speedy at getting things aligned and clamped, HHG seems like a disadvantage to me. It's not like it will make the repair 'sound' better. Here is a great opportunity for Titebond IMO.

In any case, no matter what the adhesive, do try some dry run assemblies...

I am not a professional repair person, so take this comment with that in mind.

I absolutely love hot hide glue, and only use something else if I have to. Your situation is one in which I would feel like I have to use some other adhesive.

Leave aside for a moment the concerns about how heat from a silicone blanket might affect other things, like the finish or other joints (although these are valid concerns). How are you going to do your work through the soundhole with all of this extra stuff going on? Hot hide glue is hard enough to work with when you can reach everything. You are going to be doing everything with one arm, without being able to see (touch alone). The glue has an extremely short open time, so the clock will be ticking. You are going to maybe get more open time from the presence of the blanket, but then you have a hot blanket inside the guitar along with your arm. This all sounds too risky to me.

Titebond and a StewMac brace jack, along with a small blade for spreading glue in a tight spot (feeler gauge, maybe) are the tools I would use.

The new stew mac brace gluing tool might work. It is a brass handle that holds a pipette that can be filled with hg. You can warm the brass tool giving you more time get the glue in.

HHG will be a hard one . Here is where fish glue or tite bond would be the glue of choice. There are a few questions
Usually this is a clean break if it isn't they you may need to rethink your approach. While HHG is a good glue it is not miracle glue.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Chris let's see some pics eh? Pretty hard to comment when our situational awareness is totally dependent on the written word on an internet forum.

If you have an IPhone or other smart phone I've found that they take excellent pics inside the box with the flash set to "on" and a few practice runs to make sure I have the phone pointing where I want it and not upside down. Sound like I've been here before to ya.... I have and it usually takes me about three tries to get the pic that I want inside the box.

I'm being reserved with comments pending more info (pic) but when you say a break in a brace there is also a possibility that it will need to be "sistered" and not just glued back down.

If it is just a loose brace but the brace is not compromised as the others have suggested I frequently use Titebond Original because of the decent open time and the blind nature of working through the sound hole as Don mentioned. I also frequently use a feeler gauge to push glue under the loose brace in combination with a hand outside the box pushing downward pumping the top if you will in an effort to 1) expose and expand access to under the brace and 2) to let the pumping action help distribute glue under the brace. Kind of like CPR but without the drama....

HHG is wonderful stuff but not so good when up against a clock and working blind. If there is any chance that the glue, HHG may jell before your clampage is in place use Titebond.

As for clamping lots of ways to go here too including magnets, long reach clamps and cauls, brace jacks including a shop-made stick if you will with a notch to capture the brace or braces if there is a lower brace in the area to assist.

Funny thing here, brace regluing can at times take longer to figure out the cool approach that we want to take than the actual work...

I agree with Hesh the one thing I can tell you is that most brace breaks are tricky repairs. Do a dry run first so you know your clamping technique is valid. You have 1 shot to get it right.

Sometimes this is a job for CA. I have on clean breaks clamped up the braces and allowed the CA to wick in. Tite bond and fish glue are also good as they have working time to allow finesse .

Sistering on 5/16 Martin braces won't work as they are shaped and not flat so you have to get this reglued clean. The Upper part of the X is more compressive load bearing the the lower. If the break is at the joint , the structure is compromised and you may have to rethink this. please post pics it makes the advice more specific.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I used CA once for a brace repair. It seemed to work fine. I noticed on some sample tests that some wood needs to be flooded twice, with a day in between. It seemed like the first application all soaked into the wood, but then it sealed the wood so the next application held.

The brace repair I did also included a crack in the redwood top. The CA wicked through from inside and discolored the redwood. So, if you have a crack through the top and it is spruce, I have heard that CA can really discolor spruce.

Thanks for the advice. I am new to HHG and didn't realize that titebond and fish would be compatible. The brace is not broken. The original joint gave way- leading me to think that the hhg gelled before it was clamped. I will try either fish or titebond (any reason one would be better than the other here?). There is a small crack in the top. I will wick HHG in here to close it up.

Just out of curiosity, what is "sistering"?

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Let me ask you something
is the brace loose or cracked ? Big difference

Sistering is gluing a piece along the side to reinforce the brace . I don't use wooden patches I prefer cloth and run them to cover the entire joint .

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

If the brace is loose and you used hot hide glue originally you should use hot hide glue for the repair. The fresh hot hide glue will reactivate the old glue. I would warm the interior of the guitar and the top area over the brace to give yourself a bit more open time. Use a thin spatula or feeler guage to spread the glue liberally in the joint and clamp. After the glue has gelled you can release the clamp and clean up the squeeze out and reclamp.
If you plan to use titebond, you will have to clean all of the old glue from the joint before regluing.

It is loose.

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It was originally glued with HHG which is why I was planning on using it for the repair.

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HHG would be the first choice, but not for someone new to the stuff. Titebond will give you more time and will work fine.

The advantage of fish glue is that you have more then enough open work time to get the glue in properly and cleaned up before it sets.

At the sake of going against all the real pro's...

I wouldn't use Titebond over HHG. It will not stick. Titebond is not a very good glue if you are not gluing wood to wood.

If you do then you will have to sand the joint to get a good wood to wood contact which means sanding the underside of the top as well as the brace.
For repairing braces, I have a little electric space heater and I heat the area I am working up so everything is warm. I have a 6' wide closet in my office that I removed the doors and have a small bench where I do all of my fret work that I can get pretty warm. I then use a hair dryer to heat the area where the brace is just before I glue it up.

You have to have your game plan down and work quickly even with heat.

There may be a trick that someone knows about getting Titebond glue to stick to HHG but I have not found it.

Best of luck.

Bob

I agree. If the brace has a loose joint, and it was originally glued with HHG, then repair should also be done with HHG. Anything else will be unreliable unless the joint is thoroughly cleaned and prepped, which is probably impractical in this case.

Ditto on the hot room also. I would slop it in quickly with a brush and clamp it up. Don't be chintzy. It takes a decent amount of hot glue to melt the old dry stuff already there. If you worry about a neat job, you'll get a bad joint. Clean up can be done later.

BTW clipping a heat blanket to the inside sounds like a disaster waiting to happen.

Couple of things to add:

Regarding the crack CA is often NOT a good choice although there are times when it's a great choice. The thing to know.... when discussing how we might go about repairing something Lutherie related is that you really have to have the instrument in front of you to have the opportunity to fully understand your options.

For the crack it would be irresponsible to not also adress what caused it. Was it low humidity, a blow, someone sat on it, someone's ex shot it, etc. Understanding what the causation was/is provides the service provider with also providing the additional value of decent advice. An example would be the guitar dried out so here is a guitar humidifier that you should charge and start using....

Anyway the crack should be closed prior to gluing regarless of what glue you want to use. We bag em in a large garbage bag (appripriate for O*vations...) with a large car wash sponge in the bottom of the bag. A couple of days hanging in say 75% RH inside the bag and most cracks that have not been open long will close.

HHG, Titebond, Fish are all decent choices to glue the crack followed up by a cleat or more depending on the nature and location of the crack.

Regarding HHG glue use where HHG had originally been used there is nothing that says that you have to stick with HHG.... For all of time instruments have been assembled in many cases with HHG originally and then when your uncle Eddy sits on the thing the repair person may have used......... drum roll please......... TITEBOND Original! And yes indeed it will stick just fine AND stay stuck.

Although it's noble and even a pretty good idea to continue to use HHG where it was used prior if the circumstances are such that you cannot use HHG and get all your clampage in place before the stuff jells HHG is a poor choice....

I wanted to also introduce another choice that some may view as odd for me since I have been well known to not be a fan of Franklin bottled hide glue. Over the past summer a couple of people who I greatly respect and are very well known in the industry (you likely respect them too) have been working with the bottled hide glue with decent results. They do want folks to consider though learning the Franklin date codes and only using bottled hide glue for important structural stuff if the glue is fresh since hide glue is organic.

As such the bottled hide glue would be closer to the original HHG that was used but with the advantage of a long open time. Might be a good choice and I learn new things every day and am never afraid to admit that I was being too narrow in my own hatred of that rasta imposta bottled Franklin hide glue...

But back to using Titebond or other glues where HHG was originally used. It's been sed countless times for decades now.

Regarding preheating, hot rooms, etc. Unless you can be absolutely sure that you are concentrating any applied heat to ONLY the area where you want to reflow old HHG be advised that it's not uncommon for other things to come loose from the heat. Several years ago a guy I know who wanted to fix his J-45 bridge plate removal himself split the top and loosened other braces too. Don't be that guy....

To the OP so you can see that you are receiving lots of answers here some of which are not in agreement with others. My question to you, and it's only fair that since we are helping you out that we get a shot at a question too... is what do YOU think that you should do now that you have lots of advice and you are willing to take this one on yourself? I'm asking because part of the value that the rest of us might have an opportunity to deliever to you will be if you have learned anything of real value to you. Curious minds wanna know?

As Hesh points out TITE BOND will stick. There are too many inexperienced assumptions. HHG is a good glue but it isn't the miracle glue . When it comes to repairs there are times modern glues are the glue of choice. I have tried Franklin Hide Glue on recommendation from Frank Ford and I have to admit , if it is fresh it can do a fine job.
One has to be careful of internet assumptions. Many time "I read on the internet" can lead to disaster . The key to any good repair is to establish good joint integrity. That is the key to success. Any joint that has to be forced is a joint waiting to fail.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

@ John and Hesh,

I know you have heard and seen pictures of my Gibson J-40, I did that guitar a couple of years ago. I got it for a song but it was ready for the trash heap and both of you would probably have not even considered working on it. It had been stripped, the neck was off and someone had tried to reset it and failed. It had 2 back braces loose and 2 of the X braces were loose (that is a double X braced guitar). The only good part about it is it didn't have any cracks and the neck was straight. I could see inside and someone had slobbered glue inside to fix the braces. I decided the best way to repair it was to just remove the back since it was a mess. What I found was all the loose braces had been glued with Titebond over HHG. all but one of them were loose and the one that wasn't popped off as soon as I put pressure on it. In cleaning the mess up I found I could peel the Titebond right off the places where HHG was used and it was stuck fast were there was bare wood. I cleaned everything up and re-glued it back with HHG.

So from very recent experience I would have to say that Titebond does not stick very well to HHG. I have not personally done any tests but you can be sure the next time I mix up a batch of HHG I will do that test and post the results. If I am wrong you already know I will be the first to say so.


Cheers,
Bob

So I went ahead and used HHG for the repair but no heat. I had a bit of an advantage- soundports on the lower bout right where the brace had lifted. This made it much easier. I was able to see rather than going in blind. I placed a wedge under the brace to lift it slightly and then was also able to apply the glue. I used a syringe with a straw attached to apply the glue and then used a brush to spread it and push it under the brace. I quickly removed the wedge and placed a cam clamp on the brace, pumping the clamp tight then loose multiple times to draw the glue in. I left it clamped for 5 minute and then removed the clamp and cleaned the glue the best I could.

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I have never been much of a fan of soundports but maybe I will have to re-think that...

Good to hear you got it repaired with no problems.

Cheers,
Bob

I will say that unless you know the guy that did the work you can't use one example as the true result. But I am glad it worked out for you. The HHG should have been clamped about 6 hr.
A reglue joint does need to be cleaned , to just work glue into it , you may also be adding contaminates like dust and dirt. I have done and seen many repairs of tite bond and white over hhg. My method is to use a palet knife and work it into the crack , Then scrape out the glue and add some water. Then work in glue.
HHG and fish are very compatible. HHG and fish glue are able to redissolve back into glue but it takes some technique. This is why violin makers love the stuff.
Having the soundport is a handy access

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

What John said and we just can't know what the instrument that you worked on had been subjected to and hence the likely condition of any of the joints on the thing.

Repair work is very much a case by case thing where one's approach has to be dictated by the facts on the ground or more specifically what we have to deal with on our bench and what we know and what we can find out about.

We've been doing a long term restoration on a nearly-pre-war-Martin, I'm speaking of the civil war... and even though it was masterfully assembled with HHG the conditions that the guitar was exposed to over the last century and before... make the HHG joints unreliable. In this case if a joint, even a HHG joint, is unreliable the options are to remove the back and remove, clean up and reglue braces with new HHG. And that's our approach, one of them anyway...

Then there is the client with a $395 A&L with a popped brace because his room mate tripped while using his bong and fell on the thing... There is a partially loose brace, the original glue was who knows what.... and some Titebond, proper clamping, and some time and she's good to go. Still have not figured a way to get the bong water stains out of the sound hole but the point is that every repair is potentially different and has to be evaluated for it's own merits.... or not....

And please don't read into my last example as a penchant to do lesser work on cheap instruments - far from it. I would not be able to provide value to the A&L owner if my only club in the bag was to remove the back, rebrace the thing, and then charge them $1,022.14... This is also why when I read a post where someone is critiquing previous repair work and being critical I always know in advance that we just can't know what the mission, budget, dealing with the current steward, etc. was like for the previous repair person. We at times turn away work if the client wants to dictate the approach and that direction includes doing lousy work. A reputation is far more important than a fast buck - always!

That's why these forum questions with often little information, no pics, no situational awareness, no opportunity to interview the current steward, etc. are always dicey to answer on any forum. As John says we can't know what we don't know about the thing, etc.

So when someone disagrees with me on any forum my take if there is nothing to learn from the conflicting reply is some will, some won't, so what.... next. I'm not going to take it personally that folks disagree with me and instead simply enjoy the work that I do, know that I always do my best, and know that my mentors are top shelf in all respects, and get on with it. It's never personal but it's always professional....

I'll add too that having been on both sides of the fence with Lutherie now meaning having contributed (and learned!!!!) much from certain forums I also know that the professional world of a busy repair person is very, very different from what you guys discuss here.

Often it's the case that the time it takes for a thread to run and grow and die on it's own accord on any Lutherie forum is enough time to piss off a waiting client who placed their trust in the repair person with the honest expectation that that repair person will know what they are doing. Clients are not just paying for the task to be done they very much paying for an expectation that the service provider will be both highly skilled as well as highly knowledgable about Lutherie and worthy of the huge trust placed in us.

As forums debate the academics of this or that out in the real world hundreds of guitars are repaired daily and delivered back to their current stewards once again whole (hopefully most of them are that is...).

Anyway my point is that my observation of what makes a great repair person is not only the knowledge, the skill, but the ability to execute reliably and predictably and get things back repaired and repaired well in a timely manner. I've also learned that some of the best practices that certain Luthiers have developed may be something that is frowned on on certain forums where the current crowd may lack the ability to keep an open mind as opposed to summarily dismissing any technique because it's not how they may have done things or thought that they would do things.

Recently popped off brace that is still partially glued and difficult to get under to clean out. Clean it out as best you can and glue with the glue that can be used in accordance with it's qualities (open time, etc) over attempting to use something with little open time when the repair person's chops just are not there for the application that may be difficult to clamp quickly.

There is a lot to to be said for what works and keeping it simple too. This is NOT rocket science, good thing too, because I would hate it if a guitar exploded 20 feet above my bench....