Are cleats really necessary to repair top crack?
 

Hi,
I recently purchased a used Seagull S6 Coastline acoustic guitar with a cedar top and laminate back & sides. It has a nasty 6-inch vertical crack (following the grain, straight through the wood) from the bottom of the lower bout to the waist about 1-2 inches from the right-most edge. The crack was caused by impact during shipping as opposed to humidity...no idea if it's stable but a guitar tech told me that it would continue to spread along the edge if left unrepaired.

I'd like to try repairing it myself given that it's an inexpensive guitar and I have purchased some Titebond wood glue and a C-clamp to hold it in place, but I'd like to avoid using cleats if possible. Would my attempt to simply glue it shut be futile or do you think it would suffice to make the crack stable?

I can post a photo later when I get a chance...

Appreciate any help you could provide since I'm new to guitar repairs!

Thanks,
Tom

Personally, I would not repair it with Titebond. Reason, it will neve be able to be repaired again if it cracks again there or doesn't work the first time. Titebond will not stick to Titebond, and getting it cleaned out of a crack is a bear, without spreading the crack and making it worse. As to cleats, it really depends on the crack and where it is. If it's in a place that's stressed, cleats, or a cleat, would be a good idea. If it's in a non-stressed area, you might get by without them. Hot Hide Glue or Fish Glue would be your best choices for repairing the crack. That way, if it splits again, or doesn't work the first time, it can be repaired again with either, without cleaning out the old glue. If you can't find Hot Hide Glue, Knox Gelatin will work just the same way. Put some in a little bottle, cover with water and heat to 140 - 145* and use it like glue, cause that's what it is.

Go to Frets.com and look up crack repairs. I'm sure there are instructions.

yes
 

A lot of people don't know what Titebond is.

Titebond *IS* hide glue. Hot hide glue is crystallized and liquified under heat. Titebond is the same glue with a urea(iirc) based solvent. Once the solvent evaporates and cures you have the same protein bond that is reversible with heat.

From your description I'd highly recommend cleating. It doesn't have to be pretty to be functional, just don't spill lots of glue inside the top.

Waddy offers you a good option, but hot hide glue is a lot more effort to work with than the Titebond's. I use the titebond glues almost exclusively. Titebond II is water resistant, but not water proof and can be washed off a finished guitar with a water-dampened cotton ball. It is best not to spill onto unfinished wood other than glue joints, since scraping is the best way of removal. Titebond 3 is waterproof, and should only be used in special circumstances, hence not recommended for your job. Titebond advertises their glue joints as stronger than the wood it is joining, and every test joint I have ripped apart so far has ripped wood grain next to the glue joint, but the glue joint itself has remained well in tact.

If the crack can be closed well, Titebond II is another fine option to add to Waddy's suggestion. You don't want to have to fill a crack with Titebond II, however, since it is not designed for filling purposes.

If you can slip a piece of paper through the crack, my advice is to steam it shut before attempting to glue it. If not, I would use Titebond or Elmer's Carpenter glue and run a bead on top of the crack. Push on one side of the crack to move the wood up and down a bit and work the glue into the crack. Then work the glue into the crack with your finger. When you are sure the glue in completely worked into the crack, clean up the excess glue with a rag or paper towel moistened with water. It is my opinion that you should not have to side clamp the crack to hold it shut. If it takes force to hold it shut, it will be under stress when you remove the clamp and it could crack again, maybe in a different place. I would stem it shut. There is a tool you can buy to do this or you can make one; I am sure someone has plans for it somewhere. I am aware of the steaming technique but I have never done it. It's ok if you have to clamp it to line the edges up, though. Put wax paper over the crack so your clamp doesn't stick to the glue. If you do have to vertically clamp it, use a caul made out of a piece of wood to spread the clamping force over the crack. Put another caul underneath, also with wax paper.

Knox Gelaten also tastes better......................!!

There is a "Titebond" Liquid Hide Glue. It is loaded with urea and a whole bunch of other chemicals to keep it from spoiling. I have read reviews that say it's OK, but it has so much other stuff in it, I question the purity. It also has a pretty short shelf life, and I have seen stuff in stores that was past its prime already. Also, I have tried it and I have also tried Old Brown Glue(Hide glue with just Urea and no other chemicals), and I wouldn't use either on an instrument I cared about, as they don't dry to a crystalline hardness, but stay a bit rubbery. But that's just me. I assumed, and maybe it was incorrect, that the OP was talking about Titebond Original which is an OK synthetic glue for general guitar making. I have nothing against it, and I use LMI White Glue, which is similar in some ways but dries harder and clearer. However, I wouldn't use it for crack repair due to the issue of not being able to repair the repair if something goes wrong. I wouldn't use LMI White either for the same reason. Neither will stick to itself once dried in the crack.

I agree that if the crack is open, the guitar should be humidified until it closes up by itself. Good way to do that is put it on a stand, put a dish on the floor under the guitar with a wet sponge in it, and put a plastic bag over all of it. A clear bag is nice so you can see what's happening, but any bag, like a garbage bag, will work.

Fish glue is a good liquid collagen glue that you can get in small amounts from Lee Valley. They sell a little screw top bottle with a brush in the top, similar to a Nail polish bottle. Fish glue is liquid at room temp, has a long open time, which helps for things like this, cleans up easily with water, and dries pretty clear. It does, however take longer to fully cure than other glues - 12 hours, at least - 24 would be better. With Fish glue, you can even wash dried glue off with water. The good thing is that it sticks to itself, like hot hide glue does.

Titebond Original is aliphatic resin, not hide glue.
I almost never cleat an impact crack that is tight, especially one that is in an area with low stress.
I have repaired many, many cracks with Titebond Original.

Photos of the crack
 

Wow, thanks for all the great responses! As promised, here are some photos of the crack:

https://docs.google.com/file/d/0Bzbm...it?usp=sharing

https://docs.google.com/file/d/0Bzbm...it?usp=sharing

https://docs.google.com/file/d/0Bzbm...it?usp=sharing

YamaYairi: I'm a bit confused by your recommendations above. If the crack can be closed by gently pressing down on the part that protrudes out from the body (presumably due to tension from the strings), would that constitute enough "force" to warrant using the stem technique instead of clamping & gluing?

All: Any additional advice based on the photos? As of now, I'm leaning toward continuing with my plan to clamp & glue (with Titebond) but am still torn on whether to cleat. BTW, if I do cleat, is there any reason why I would need to use a specific type of wood for this cedar top? Again, it's not an expensive guitar...I just want it to be stable & functional.

Thanks again,
Tom

titebond
 

Ah, yes I was referring to

http://images.rockler.com/rockler/im...252-01-200.jpg

I forgot Titebond also makes non-hide glue

I'v had 100% failure on everything that I've used it on. Once the humidity peaks in the summer and the temperature reaches 80's or so, the joints under any stress let go. I had a lute top that I used it on that experienced catastrophic failure under full string tension: I didn't know wood could be bent that much longitudinally.

I've tried more than one bottle, to ensure that it wasn't just a bad batch.

I'm not alone. One poor soul put an entire guitar together with the stuff then wrote to Fine Woodworking for advice when every joint on the guitar started to fail in the New York summer. Fine Woodworking published the response of Grit Laskin who, paraphrasing, said, "Too bad: don't use that stuff".

Others have had success with it. But, from my experience with it, I won't use it for anything guitar related.

John Arnold,
You mentioned:

Looking at the photos I posted above, would you consider this an area with low stress?

Thanks,
Tom

Now this gets interesting. Your photos show impact on the soundboard edge near the bottom right corner of the guitar. The top has possibly come loose from its lining, This is a more challenging repair than just a crack along the grain. Grain cracks are fairly easily dealt with, but getting the damage near the binding/lining/top-end-grain repaired well requires more effort.

If it is DYI, you can use a flat caul covered with wax paper to try and glue down the top so it is flush again at the edges. Then, in a separate operation, you could glue the grain crack which, with skill and maybe a bit of luck, might level itself off better once the crunched area is rectified. Just be careful not to get any glue into the grain crack while glueing the first edge crack. Hypodermic syringes loaded with 15 or 20% watered down Titebond II can be your friend for this operation.

Sorry, that was a typo. I meant, "Steam it shut."
From the photos it looks like the edges of the crack don't line up. I agree with the advice to repair the point of impact first, then the grain crack. I think you will need to clamp the grain crack on top and below, using cauls with wax paper, so the wood lines up. It's hard to describe this, but if you can push on the wood and get the edges to line up and the crack is tight, then you shouldn't need to humidify the guitar to close the crack, just glue and clamp. I would say that if you can't stick a piece of paper through the crack while holding the edges so they line up, you don't have to humidify. In fact, humidifying at that point may make it difficult to line the edges up.

Ok, thanks for the advice, guys. I went ahead and attempted to glue & clamp the main vertical crack because the "crunched" part where the impact occurred along the bottom appears to my untrained eye to only penetrate the finish, not the top wood. In any case, I tried to get some Titebond glue in there as well but it was difficult. In fact, I feel like I wasn't able to get much glue in the main crack either...I guess we'll see in a couple days.

So assuming this worked, I take it the next step is to glue some cleats every 2-3 inches along the underside of the crack? In order to get my hand in there I'll need to remove all or most of the strings from the bridge...is this OK or should I loosen the truss rod first?

Thanks again for all the help!
Tom