Re: Advice needed on fixing Crack in soundboard
First things first, in order to fix the dent, from the looks of it, that crushed finish will have to go. I'm guessing since it's a Samick that it's poly. You're better off doing a finish repair with superglue than anything else.
Using an xacto knife with a number 11 blade, remove the crushed finish around the area. Clean it up as best you can, you don't want a dirty work space, ya know? You'll need to steam and swell the dent out, much like you would do on an electric using a soldering iron and damp rag. For time's sake, we'll assume you know what to do here.
Once you have the finish removed and a relatively level surface, it's time to get the crack to close. By pushing on it from both inside and out with light pressure, see which way the grain split, as this will tell you which way you need to open the crack to get glue in there. Grain very rarely (especially on cedar) splits exactly vertical, and is usually on the grain axis (tops are usually completely quatersawn to 75%, judging by the slight amount of silking you have on the top, you're probably at a 80 degree slant), and sometimes the only way to glue a crack due to this slant is from the underside.
For the sake of ease, we'll assume that the top split and will be accessible from the front of the guitar. Before we do any gluing, make yourself some cleats out of a similar wood. I prefer maple, as it's still very resonant but much stronger than the top wood. Some guys do triangles, diamonds, or rectangles. I prefer diamonds. There's no right way to do it, I just like the way they look. Frank Ford's site Frets.com has some great info there about cleats.
Decide where your cleats are going to go, and using a sewing needle, poke holes through the top for your line. Then, poke a hole through the center of each cleat. Using fishing line, tie a knot in one end, run it through the cleat, then run it through the hole. I like to put a little small wooden washer on the underside of the cleat, so I can pull the string and get even pressure all the way around. Use a very like coat of Tite Bond to glue them to the top. But not before you glue the crack shut, I skipped a step. Whoops.
Using Franklin's Tite Bond wood glue, mix it up 6/1 with purified water (yes, purified). It'll thin it a bit, but not so much that the glue looses strength. Push on the underside of the top to open up the crack, and work the glue in there as best as you can. Once you've done that, run your cleats. For something about that size, I'd say two.
After you're done gluing, using a bar clamp, run it from the treble bout to the bass bout and put pressure on the top.
After the glue's dry, prep your work area with the xacto knife and do a superglue drop fill. If I remember right, you do some finishing, so you know what you're going for there. You WILL have a ghost line, but if done correctly, it'll only show in certain light.
And you are correct... It's most certainly IMPACT DAMAGE!:grumble: I have a 10 year old Autistic son. He's 5' 2" at around 175 Lbs. He's generally a sweet kid, But Autistic's are prone to melt downs . When he melts down... Things go flying, get kicked ,and knocked over.
