>>993201
Get a mirror, preferably a dental style one, look where the split is inside. If there are staves/whatever-they-are (bracing maybe?) you're kind of screwed. You're looking at taking it apart (ungluing it) and doing major surgery. If not you can glue in a strip of wood, but you'll need deep reach clamps to do it and I don't know if they exist.

>tl;dr yes you can, but it'll cost you. Is the guitar worth it?

>>993208
You can make custom clamps out of wood and large machine bolts so they'll be the right length.

>>993208
Also, a boroscope may be easier to use than an inspection mirror, depending on the angle.

>>993208
>>993284
http://m.harborfreight.com/8-inch-deep-throat-c-clamp-45917.html

http://m.harborfreight.com/12-inch-deep-throat-c-clamp-45919.html

The hardest part would be snaking them in, being that they're so large. Also, this type of clamp is used when working with metal, so be gentle. And use some kind of caul, like a sacrificial clamping surface. A piece of 1/4in ply running the length of the cracks on both sides will help protect the wood and distribute the pressure more evenly. Put painters tape on the ply to keep it from gluing to the guitar, 3 or 4 coats might be over kill but it'll also soften the surface, making the clamps less likely to damage the wood. 2 clamps should be good. Don't let them hang freely, if the only thing supporting the clamp itself are the clamping surfaces wedge something underneath them to support them, these are heavy enough they can break the guitar.

If there's a brace in the way on the back use a smaller piece of ply on each clamp. Glue it to the clamp so you don't have to try to hold it in place inside the guitar with one hand. If there is a brace and it's busted loose you can try to get up in there with a small paintbrush(like for water colors) to brush some glue on it and then clamp it again. Don't try to glue both at the same time.

>>993556
Actually craft stores sell basswood and balsa "hobby boards" that are smaller. You may be able to to find a 3"x20" piece that you'll only need to cut one way. I don't know what tools you have, but scribing it with a box cutter a few times and breaking it on your knee or against a table should even work. Balsa is one of the softest woods you'll find, basswood is harder. I'd use basswood if you can find it.

It may still look bad, of so you may need to refinish it. It's a long tedious process if you have no experience, and depending on the guitar may destroy it's value, so it'll be a choice between trying to maintain value to sell later on or having a guitar that you play that looks good. Let me know if you want to know more about finishing.

Also, I'm not a luthier(though I play guitar ), I'm just a carpenter. Some of the ideas and techniques transfer, but I'm not familiar with the nuances.

I preface this comment by saying that I would recommend you take your guitar to a luthier instead of possibly messing it up, but you are posting to /diy/, so here you go anyways:

I'm copying and pasting parts of two articles on replacing the soundboard on a 1977 Martin D-35.

http://www.premierguitar.com/articles/Replacing_the_Soundboard_on_a_1977_Martin_D-35

http://www.premierguitar.com/articles/Replacing_the_Soundboard_on_a_1977_Martin_D_35_PT_2

>The first step was to remove the ebony bridge and soften the glue joint of the fretboard extension using Stewart McDonald’s bridge heater and fingerboard iron (item #4607 from stewmac.com). Then I removed the neck by applying steam into the dovetail joint while using the neck joint steamer (item #4059) to soften the glue in the pocket.

>At this point, I traced out the top to give me a reference for replacing it later on. Then starting at the dovetail, I removed the top binding using a hair dryer and channel spatula. (Had the original binding not been damaged, I would have used a delicate procedure for removing the soundboard while leaving the binding attached to the rib.) Now with the binding off, I used a razorblade and chisel to separate the soundboard from the sides, while being careful to avoid splintering or loosening the kerfed lining.

>After removing the ebony bridge and mahogany neck, and then separating the original soundboard from the body, I was ready to clean and remove any old glue or raised wood fibers from the kerfing, neck block, and tail block.

>I made a leveling sanding block from materials I had laying around the shop. For the platform, I used a long rectangular piece of Corian. First I leveled the 1/2" plank using my thickness sander and then I attached a soft rubber handle. To the bottom of this 26" long custom sanding block, I attached a length of 220-grit Stikit Gold self-adhesive abrasive paper (item #5768 at stewmac.com). This is the perfect grit and material for the job.

>>993645

>To stabilize the body on my workbench, I used a plywood cradle (#5657) and body support blocks (#5656), both of which are replacement parts for StewMac’s TrueChannel routing jig. I’ve discovered that many jigs and tools can be used in other ways than originally intended. I’m sure many of you have come across this and perhaps you’ve adapted tools this way too. Using a gentle back and forth motion, I used the sanding block to square the top surface of the kerfing.

The replacement soundboard had braces different from the original, so he goes on to address that issue.

>With a thickness caliper (#5193), I measured the original top braces and then used a guitar-brace chisel (#1629) to trim the braces on Martin’s replacement top to closely match the originals. This chisel has a specially curved blade that makes it easier to carve the smooth curves needed for scalloped braces and tone bars with feathered ends.

And he ends his article here. I'm assuming he goes on to glue and clamp the top to the body, and finish the top.

if you don't want to put a clamp through it you can put the guitar on a sturdy felt covered surface, once you put the brace in place put other bits of wood inside stacked till it makes a solid support from the back to the front of the guitar, then put felt on top of it, put a solid board on that then put some weight on it to hold the whole thing down and together...

>>993556
>http://m.harborfreight.com/8-inch-deep-throat-c-clam[...]
but this is a SFW board senpai
dat link looks a little ... l-lewd?

OH, Harbor Freight.
Okay.

If you are going to attempt any fix on this, make sure you remove the strings first. The tension on them is causing a lot of the deformation near the crack, and is the reason why it looks like the sides of the crack don't match up. You may not even need any clamping if detensioning it lines the cracks back up to each other.

Awesome thanks dude!

Yeah you could fix it but if you have to ask how you cant. This kind of repair is not something you just hack together, the body is destroyed and dry
The neck is crooked so i assume one of the supports on the inside is broken too.
It's cheaper to get a new guitar