Loose Brace question

thebolo · #1 04-15-2011, 10:03 AM

Hello,

I recently finished my second guitar. It has been strung up for about two weeks. While playing it today I noticed the brace had come loose. I test clamped it and it will glue back fine. My question is, why did this happen. I checked all the other braces and they are fine. Maybe I didnt glue it well enough? Also we are having one of those Nebraska spring blizzards and the humidity shot through the roof. Any help would be appreciated. Thanks

SteveS · #2 04-15-2011, 12:17 PM

It could be glue technique issue. My guess is that it is more of a design issue. That brace should either be tucked into the sides and linings or be carved so that it tapers smoothly to nothing and stops about 1/4" before the linings. To have it abruptly end like that is not a good thing to do.

thebolo · #3 04-15-2011, 12:32 PM

This is only my second guitar. After looking at that today I decided I needed to do a better job of tucking it into the kerfing. Do you think there will be problems down the line for this guitar? I know its hard to tell, but is it something to really worry about? Thanks again.

PS. The quote by CS Lewis is very fitting of my first two builds.

Howard Klepper · #4 04-15-2011, 12:37 PM

The upper end of the X arms should be inlet into the liners; not the way you have done it, but so they are supported on their undersides.

That alone is not why it came unglued, though. As Steve said, probably poor technique. What kind of glue did you use, and how did you clamp?

thebolo · #5 04-15-2011, 01:00 PM

I used Titebond II. This is how I clamped it.

I understand that it should be tucked into the lining but it is a little late to fix that now. I have reglued the brace, so hopefully it stays. I still would like to know if it is anything to worry about. I dont want to sound rude, but I intend to give this guitar to a friend and I need to know if this is something to worry about. Thanks for all your help. It is greatly appreciated.

SteveS · #6 04-15-2011, 04:09 PM

OK - Sorry but there are plenty off problems. Make that lots of learning opportunities here.

First - Titebond II is a very bad choice of glues. That water tight formula is weaker and more subject to creep. Throw it all away and only use Titebond original, LMI white, Hot hide or fish glue.

Second - White glue and yellow glue will not form a good bond when you re-glue unless you remove all of the old glue first. This is not true for hot hide and fish glues. (Epoxy is another exception.)

Third - Your clamping technique is not at all appropriate. Ideally, you need each clamp point to be no further apart than the height of the brace.

Quote:

Originally Posted by thebolo

..... Do you think there will be problems down the line for this guitar? ........

Sorry, but yes.

thebolo · #7 04-15-2011, 04:34 PM

So different glue, more clamps, and I have an f-up of a guitar...I'm not being bitter towards any of you, I'm just really feeling a like crap because I didnt build it right. Alas, the only lessons learned in life are hard ones. Just to depress myself even more, what kind of problems can I expect?

Tim McKnight · #8 04-15-2011, 05:02 PM

Another possible problem is too much clamping pressure using screw clamps. You can actually force all of the glue out of the joint (which is called a starved joint). You may also want to consider using a Go-Bar deck or vacuum which can apply a more appropriate amount of clamping force.

I also see a possible problem with the end of the upper transverse brace. It appears to be lifting as well. Perhaps you might want to inspect it while you are at it.

It may be a good learning experience to pop the top off and rebrace [if} you want to reduce to odds of reoccurring problems down the road.

SteveS · #9 04-15-2011, 05:17 PM

Quote:

Originally Posted by Tim McKnight

......It may be a good learning experience to pop the top off and rebrace [if} you want to reduce to odds of reoccurring problems down the road.

Hey Tim,
I thought about that also. I assume that the neck block is also glue with Titebond II, so it might be a losing battle.

Thebolo,
Sorry about all of this. Do you have The Book by Cumpiano? If not, get it a follow it closely. It is best to use proven techniques for your first builds.

thebolo · #10 04-15-2011, 05:25 PM

I checked all the other braces and they seem fine. I've built two other guitars like this and I havent had any problems with them. I am currently building in the shop outside and my room for a more controlled climate. I would really like a go-bar deck, but I will have to build one, because I havent got any money to buy one. I think it may be shadow in the picture, or not a perfect seam between the top and that part of the brace.

Steve, I have been following Cumpianos book closely. It has been very helpful.

Kent Chasson · #11 04-15-2011, 05:29 PM

Looks to me like there is something going on besides glue failure. That's a pretty large gap and that's not where one would expect to see glue failure from string tension on a new guitar. You may be correct that humidity is involved. Or, is it possible it suffered a blow?

It's not a good sign of things to come but it may not be a sign of an imminent early demise either. Depending on the friend and your arrangement with them (and how much you like the sound as is) I would probably go back in with a small chisel and remove those three sections of lining under the X-brace end (and the 2 under the transverse brace) and replace them with full height, full width lining sections that butt up against the brace ends.

It may need to be re-topped at some point if more things start to creep and fall apart but nobody can say for sure. If your friend is up for it, try the easy fix first and see what happens. You can always re-top it later.

thebolo · #12 04-15-2011, 05:45 PM

The friend who is getting it doesnt even know about it yet. I've been really careful with it, and if it got dropped nobody told me about it. I will definitely glue more kerfs under the braces. Like I said this is the first problem I've had with a brace coming loose, and was wondering what the deal was. Also, the guy I'm giving it to lives in Las Vegas and I live in Nebraska, so we dont really see each other every day, but if it ever needs fixed, I will take care of it. Again thank you guys for all the help. I still feel like I've failed, but I will get over that eventually.

gregg · #13 04-15-2011, 06:09 PM

Quote:

I still feel like I've failed, but I will get over that eventually.

You haven't failed, most of us have encountered these types of problems before.

if you keep building there will be plenty of other issues to get over, so the quicker the better.

Good Luck!

GG

thebolo · #14 04-15-2011, 06:29 PM

Quote:

You haven't failed, most of us have encountered these types of problems before

Dont make me feel better with your logic

. I'm feeling better already, and I know what to do better on my next guitar.

KolayaGuitars · #15 04-15-2011, 06:56 PM

Yep, chin up soldier! This is one of the hardest and most frustrating crafts i've ever endured, but it is worth it. And, life goes on. So a brace came loose, its not the end of the world, not even if you have to re-top it. You're on the right track and being humble enough to ask questions is a huge part of learning! I look forward to seeing more of your work in the future!