Side crack repair.

[Ned Knepp]

A friend brough me his son's "new" Hoyer Archtop. It is a pretty nice instrument that plays well and is in excellent condition except that someone seems to have dropped on on the end pin at some point.  The end block appears to be fine with both an internal inspection and a look through the end pin hole but the lower side cracked, starting from the end pin hole, running toward the lower waist for about 8 inches. 

 

The end of the crack, furthest from the hole, can be pushed back into place easy enough but the portion of the crack which is over the tail block will not close up even with a LOT of pressure.  Hydration hasn't helped the issue much. It's as if the side were in tension before the accident and just doesn't want to close up again now that it is released.

 

I've never run into a crack on a side like this one. I've always been able to close up the side cracks I've come across even if some do take a lot of pressure and special jigs to hold thing in place.  I suppose I could take the side loose from the end block  but that really seems like overkill given the condition of the rest of the instrument.

 Have any of you splinted a side crack? Is this a viable technique for side repair? 

 

Ned

[Chris Rochow]

Do you use spool clamps? They close a crack quite nicely. I use them all the time on side cracks. Very precise, and easily controled.

http://www.stewmac.com/shop/Tools/Clamps,_support_tools/Spool_Clamp...

[Len Biglin]

I think Grahame might be on the money here , better look at the inside of the cracks? See if you can push a feeler guage thru the crack .

[Ned Knepp]

Hi Chris,

  I haven't tried spool clamps. I have  some that I made up years ago. I can try some to see if they do any good.

 

Ned 

[Howard Klepper]

Either the tailblock is cracked, or the side is separated from the tailblock.  This is the issue you need to address in order to get the crack closed.

[William F.Eden]

Don't worry about the tail block the super glue will fix that

[Howard Klepper]

One of us must be misunderstanding the problem.  I thought it was that the crack in the tailblock area won't close when clamped.

[Jeff Highland]

I'd agree with Howard K and not rule out the tailblock being cracked, even if it is not obvious.

I;d be pulling the tailpiece and  clamping directly on that area front to back  to try and close the crack, before resorting to filling.

Then  you can wick CA into the area

[Pierre-Antoine Roiron]

I would go for super thin superglue first and some spool clamps, just to be sure that any tiny crack would be glued, then use some thick superglue to fill the crack. I use that kind of trick when I don't want to spent too much time on a crackr that does not seem too dangerous or the guitar structure. Never had problems till now.

[Ned Knepp]

I can tell you this. There is no sign of a tail block crack, odd as that sounds. Probing the crack indicates that it stop at the thickness of the side.  I have discovered that the narrow end of that the side below the crack "clicks" when I tap on it over the tail block so it is loose there but nothing else sound like it is anything but solid.  Clamping it either across the body or top to back does very little to help close the crack. The edges are turn up just a bit so a caul will help a bit but, so far, nothing I can find short of disassemble seem to promise to close up the crack.

 

I am going to talk to the owner tomorrow and tell him what I've found and what you guys have brought up. (BTW, Thanks everyone.)  I have to decide if I am going to try to do this repair or not. He wants me to do it because I'm cheap (free) but I have to decide if I want to deal with it and him. I wouldn't hesitate to do if it were my guitar so I guess that decides the "it" part of that decision, but it's not mine and while he's a friend, he can be a touch paranoid sometimes  My concern is that I may be taking "ownership" of this guitar in a way that I'm not comfortable with.  I'm an amateur but I can still have "client" problem.

 

Thanks again to everyone for the discussion. I'll let you know what I decide tomorrow

 

Ned. 

[Mike Kolb]

Hi Ned.... in thinking about this dilemma, is there a possibility that the guitar (post-crack) became heated, causing the glue to fail at the tail block? If so, the glue would have rehardened and now be holding that split wide-open, and rather nicely. I'd be tempted to steam the block loose and see if that's what's keeping the crack open.

In any event, it's an interesting problem and I would love to hear the eventual outcome! 

[Ned Knepp]

Well the guy who owns it didn't show at church today so I guess I have another week to decide what and IF I want to do it. 

 

Everyone seems to agree that this is weird, Mike. I hadn't thought of the idea that that glue reset. My inspection of the guitar doesn't show any sign of it having been exposed to either too much moisture or too much heat. That's actually part of the puzzle to me. I can't find ANYTHING wrong except the crack. 

 

When I have seen gaping cracked sides in the past there is always some off set in the edge or a distortion in the binding or something to indicate movement of the wood.  In this case, there isn't anything except the slightest bit of bulging at the crack and, as I said, pushing it back flat doesn't even begin to close it. The guitar sides measure to be the same width on either side of the butt joint at the tail with nothing except the crack to show there is any difference in the width of the sides 

 

I wondering if my attempts to hydrate the guitar are not enough. It just doesn't make sense otherwise. I'm playing with ideas of directly wetting the crack site with water to see if it helps close things up. It just doesn't make any sense other wise. As it is right now, this side of the guitar would be (is) narrower than the other side. If I cut this free of the binding on one side and pushed the crack flat and closed I would be left with a gap between it and the binding. all of this screams "dry" to me but I have tried to rehydrate this guitar for some time now. 

 

Has anyone every tried applying water directly to a split area like this.  I thought about trying steam and I though about applying drops of water over several days but I'm worried about doing more harm than good.  Any ideas?

 

The more I look at this "simple" repair, the more convinced I become that it should go to someone with more experience BUT I also want to know what was done and why. After all, that's how I learn.

[William F.Eden]

My exp.in wetting the wood was not very good .It just made it bulg out .Bill.''''''''''''''''''''''''''''