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D-28 with cracked heel
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10137&t=49720		 Page 1 of 2
Author:  Pmaj7 [ Fri Sep 15, 2017 6:09 pm ]
Post subject:  D-28 with cracked heel
It's a typical crack right through the middle of the heel, however on this one it seems like the dovetail joint is loose also on the top half. Next to the fingerboard.

In addition to gluing the heel, do I also need to somehow get glue into the dovetail??
Author:  Hesh [ Sat Sep 16, 2017 5:53 am ]
Post subject:  Re: D-28 with cracked heel
Hey Pat. Might you have any pics to share my friend?

First question is is this ax with the original owner? If so this may be covered under warranty if it did not result from any accident or abuse. If the ax could benefit from a neck reset as well (is the neck angle deteriorating from f*ctory specs/set) the owner may be entitled to have this including the cracked heel handled free of charge by a Martin authorized service center. These days for a neck reset to be covered there has to be a visible gap. If the Dovetail seems loose and it was not as a result of accident or abuse this may be covered including repairing the heel crack.

If not, second owner, abuse, accident, etc. warranty is not a concern.

I'll wait for pics but some food for thought right now is if the heel is to be glued with the neck on the instrument it's key to not glue the heel cheeks to the guitar body. This frequently happens anyway at the f*ctory with over use of glue and it makes neck resets way harder in the future.
Author:  Pmaj7 [ Sat Sep 16, 2017 9:09 am ]
Post subject:  Re: D-28 with cracked heel
Hi hash, thanks for the thoughts! It was from an impact and I believe he is not the first owner anyways. It doesn't need a neck reset and I had set it up about a year ago and everything was looking good.

This picture is with light pressure applied to the back of the neck. I also just noticed that the side has cracked just under the linings about four inches out from the neck. Yikes!
Image
It seems like if the heel were repaired solidly that the string pressure would hold everything in tight. Maybe just rub some high glue into the side crack at the same time as gluing the heel.
Author:  Hesh [ Sat Sep 16, 2017 2:00 pm ]
Post subject:  Re: D-28 with cracked heel
Wow, that's a really nasty break.

Do you see the heel right next to the crack where with your minimal pressure there we can see the heel cheeks separating from the body? Even factoring in that the body is cracked too and referencing the small of the heel still attached we can see that the dovetail is indeed loose and pulling away from the body right where that crack is.

That should not be possible..... with a properly fitted AND intact dovetail joint.

We can also see what could be glue on the cheeks to body joint of the lower part of the heel. Great photo!

Pat buddy this is an ugly one and I'm concerned that the integrity of the dovetail fit is compromised because of that separation that I mentioned. We want the mechanical attachment of the dovetail to do the heavy lifting countering string tension not any glue joint. Glue is only used in dovetails to keep things in place for the mechanical joint of the dovetail to do the real work.

With this said if this was my guitar I would take the neck off, a big deal I know.... repair the heel, rebuild the dovetail on the neck AND body joint and repair the body cracks with the neck off the instrument. It's also an opportunity to "update" the neck angle even though it may not be completely ready for a neck reset. With both major parts completely repaired (this will make finish repairs on the body and neck easier....) then we reassemble and set the neck angle.

A lot of work I know but I really, really don't like the look of the heel separation indicating a compromised mechanical dovetail joint.

Also the strap button seems to be right where things cracked as well. One has to wonder if the clearance hole was not sufficient creating an opportunity for with a blow the crack to happen right through the strap button. Sucks I know!

And you're right this would not be a warranty thing since it resulted from an accident.
Author:  Hesh [ Sat Sep 16, 2017 2:21 pm ]
Post subject:  Re: D-28 with cracked heel
One more thing too if I may please.

Looking at the body I think.... the crack on the right on the side in the pic is a reflection of the heel crack. In any event the remaining crack, the body crack on the left looks unlevel at the heel. You can see the side in contact with the heel and then after the crack it's not in contact with the heel AND the side looks lower.

Might be a good idea to carefully inspect the neck block to side joint in that area as well. While in there be sure too that the neck block is not cracked.

The side may be pulling away from the neck block.
Author:  david farmer [ Sat Sep 16, 2017 3:59 pm ]
Post subject:  Re: D-28 with cracked heel
I'd Pull it apart Pat. Some naptha will tell you all the ugly truths. (like if the block is cracked)

Remember too the dovetail may get heated apart again in the future. If the heel crack is glued w/ hide, no biggy. If not and the heat opens it up...... sadness may result.

When re-fitting the dovetail to the socket, some folks just make sure the surfaces have good contact at the bottom. Or worse, shim only at the bottom. A fit like that could have even contributed to the break on this one, I'd use carbon paper and make sure you have full contact all the way up that sucker. That makes the neck block act like a giant cleat.

Just an idea:
Maybe use just enough PVA to glue the neck back into the socket. With a little luck and skill, you, or someone else, might be able to pull the dovetail apart in the future without disturbing the crack repair much. (sounds like a candidate for the Ian Davlin moistureless neck pull beehive)
Author:  Glen H [ Sat Sep 16, 2017 5:41 pm ]
Post subject:  Re: D-28 with cracked heel
Assuming the crack goes all the way through, I would at a minimum put spline through the dovetail and might even run a tension bolt/nut countersunk instead.
Author:  Pmaj7 [ Sat Sep 16, 2017 7:44 pm ]
Post subject:  Re: D-28 with cracked heel
Wow, sounds like a code red! I hadn't considered that I might need to pull the neck out quadrupling this repair bill. This all sounds like very solid advice and yes, if I was going through the trouble of taking the neck off I would make sure to do everything as solid as possible. Guess I'll talk to him and see how much he wants to spend! LOL

Thanks for all the great advice everybody! I really appreciate that.
Author:  Hesh [ Sun Sep 17, 2017 5:15 am ]
Post subject:  Re: D-28 with cracked heel
It's really in terms of pricing similar to a neck reset and a bit more. Heels can break in two during neck resets (Guilds and G*bsons because of the shallow heel shape) and it's standard fare to have to rebuild the dovetail adding wood in the form of shims and then pairing them back in the fitting process.

Neck block repair if necessary is above and beyond neck reset activity and the added time to repair and address body cracks is also above and beyond neck block activity.

Don't know what the going rates for these things in your neck of the woods (pardon the pun...) but in mine it would be around neck reset price plus approval in advance for a premium of up to 50% more for the other things. I'm real big on getting quotations correct the first time so when the client hears from us again in several weeks it's to let them know that their baby is all fixed and ready to rock.

PS: You can throw in the white felt to match the binding for the strap button.
Author:  phavriluk [ Wed Sep 20, 2017 8:59 am ]
Post subject:  Re: D-28 with cracked heel
oops_sign

I seriously misunderstood the picture...pay no attention to that person behind the keyboard.
Author:  Pmaj7 [ Wed Sep 20, 2017 12:25 pm ]
Post subject:  Re: D-28 with cracked heel
Phav, what do you mean by "lower neck"? I'm not sure I follow, but what looks like a crack in the side near the strap button is just a reflection of the heel crack.
Author:  phavriluk [ Wed Sep 20, 2017 4:26 pm ]
Post subject:  Re: D-28 with cracked heel
Shoulda' said 'lower heel'.
Author:  Hesh [ Thu Sep 21, 2017 4:47 am ]
Post subject:  Re: D-28 with cracked heel
OK I'll bite and have been wanting to even though Peter's post no longer exists.

Could the strap button have had anything to do with this injury?

Yep, it may not have caused it, the blow that the instrument took likely did that but if the button was not installed correctly it may have encouraged in conjunction with the blow that the instrument took the split to happen, to happen where it did and the crack to be perhaps worse than it needed to be.

What's "correctly" in terms of installing a strap button?

1). Clearance hole of proper size for the screw shaft and proper depth, I use the masking tape method.

2). Chamfering the edges of the screw hole to avoid finish chipping.

3). A drop of wax on the screw threads to ease entry.

4). A felt (missing in the picture) that is a bit of a hedge against over tightening before you know it or in other words you can feel things snugging up before a hard stop AND the felt cushions the button's contact with the wooden heel.

5). The location is not where I would have put it either and too far down the heel where the wood is thinner for my taste.

Who knew that installing a simple strap button has some things to keep in mind..... but they do. I've seen a music store owner trash a guitar with an initial failed attempt to install the button and then subsequent failed attempts to cover up his carnage.....

Anyway this button installation did not cause the accident to this guitar in my view but if Peter was suggesting that it may have encouraged the split where we see it I would tend to agree that that's a possibility.
Author:  johnparchem [ Thu Sep 21, 2017 8:32 am ]
Post subject:  Re: D-28 with cracked heel
Hesh wrote:
Who knew that installing a simple strap button has some things to keep in mind..... but they do. I've seen a music store owner trash a guitar with an initial failed attempt to install the button and then subsequent failed attempts to cover up his carnage.....


Thanks for the post. Installing strap buttons in my finished guitar is my worst nightmare. I do not like how they look I hate when my hand hits them playing up the neck, and when I install them I am always sure they are in the wrong location.

I have also been in the situation of the music store owner [headinwall] . I Install a tail strap button and advise tieing behind the nut if someone wants to use a strap. I do install if asked though.
Author:  Pmaj7 [ Wed Oct 25, 2017 1:31 pm ]
Post subject:  Re: D-28 with cracked heel
david farmer wrote:
I'd Pull it apart Pat. Some naptha will tell you all the ugly truths. (like if the block is cracked)
How so? Dousing the inside of the joint and seeing if any seeps through?

david farmer wrote:
Remember too the dovetail may get heated apart again in the future. If the heel crack is glued w/ hide, no biggy. If not and the heat opens it up...... sadness may result.
Are you saying to use hide because hide is less responsive to heat/steam in case of a future reset? I thought hide was supposed to be more responsive that is why it's repairable. I hadn't thought about this issue anyway. maybe gluing the heel crack with something more resistant? TB2?

david farmer wrote:
(sounds like a candidate for the Ian Davlin moistureless neck pull beehive)
Wow, that's quite a deal! There was water however, just not steam.

Glen H wrote:
Assuming the crack goes all the way through, I would at a minimum put spline through the dovetail and might even run a tension bolt/nut countersunk instead.
I can envision a spline, but what are you thinking with a nut and bolt?

Hesh wrote:
Could the strap button have had anything to do with this injury?
Could be. Do you know if those are put on at the factory or is that totally an aftermarket thing? Thanks for the install rundown also!

johnparchem wrote:
Installing strap buttons in my finished guitar is my worst nightmare. I do not like how they look I hate when my hand hits them playing up the neck, and when I install them I am always sure they are in the wrong location.

I have also been in the situation of the music store owner [headinwall] . I Install a tail strap button and advise tieing behind the nut if someone wants to use a strap. I do install if asked though.
Ditto!

I got the go ahead on this and I'm preparing everything. Hey, I guess I should have asked earlier, but is there a definitive reset toot out there?
Author:  profchris [ Wed Oct 25, 2017 6:12 pm ]
Post subject:  Re: D-28 with cracked heel
Hot hide glue releases with heat + moisture, but not with heat alone (once it has cured and lost its original moisture). Titebond, like most other glues you might use, becomes soft and gummy with heat alone.

So if you were steaming off the neck and had glued these cracks with Titebond, it could get hot enough to release or at least allow the cracked joint to slide and then re-set. Whereas the hot hide glue would only let go once the moisture had got through to the middle of the joint, which takes a lot longer (if at all - if I remove a bridge glued with HHG this usually requires heat + moisture to soften the glue at the edges of the joint, and then I need to use a blade to open up the joint and allow the moisture to penetrate).
Author:  Hesh [ Wed Oct 25, 2017 7:21 pm ]
Post subject:  Re: D-28 with cracked heel
Strap buttons on the neck are never a Martin factory thing, this one was done after the guitar was manufactured.
Author:  david farmer [ Wed Oct 25, 2017 10:37 pm ]
Post subject:  Re: D-28 with cracked heel
pat macaluso wrote:
david farmer wrote:
I'd Pull it apart Pat. Some naptha will tell you all the ugly truths. (like if the block is cracked)
How so? Dousing the inside of the joint and seeing if any seeps through?



Yes.
I would steam the neck apart in the usual fashion. I would like to know if there are any cracks in the sides or block or loose joints to repair before putting the neck back in. Some naptha drizzled on the surfaces of the dovetail socket will quickly wick all the way through and be visible on the inside with a light and mirror if there is a crack. Likewise with the joint between the sides and block. These potential issues would be much easier to detect and fix with the neck off.

pat macaluso wrote:
Are you saying to use hide because hide is less responsive to heat/steam in case of a future reset? I thought hide was supposed to be more responsive that is why it's repairable. I hadn't thought about this issue anyway. maybe gluing the heel crack with something more resistant? TB2?


A dovetail joint is likely to get taken apart again with steam. If you repair the heel crack with hide, it may open a little during a future reset. A little more hide glue and a clamp will bring it back together again as strong as ever. If the heel is repaired with some other adhesive and it comes apart during steaming you have failed glue that will prevent a full strength reglue. Also known as a mess.

Ian Devlin's current neck removal technique uses heat but no moisture for PVA glues. As Chris mentioned, Hide requires much higher temperature dry or moisture to release. My Idea was to use a little PVA to hold the dovetail joint together, (the joint geometry is doing all the work) and use hide on the heel crack. Theoretically, ( and I think it would work), the neck could later be pulled easily with dry heat and leave the heat resistant hide glue in the crack unaffected.

Based on the picture, I would pull the neck off to sort it all out. If you really must give a shot at fixing it from the outside without disassembly just use hot hide glue. That way, if it doesn't last, (and I don't think it will), you can steam it apart and not be much worse off. Putting PVA in from the outside will make for a long way home.

I would also at least move the strap button hole up to a different grain line. It might be possible to still have the base of the button or a leather washer conceal the old hole.
Author:  Pmaj7 [ Sun Nov 12, 2017 10:47 pm ]
Post subject:  Re: D-28 with cracked heel
Well I got it off. I thought there wasn't supposed to be any glue on the heel? Looks like there is a neck block crack also. Good thing I checked, thanks for the suggestions!Image
Author:  Hesh [ Sun Nov 12, 2017 11:39 pm ]
Post subject:  Re: D-28 with cracked heel
Welcome to our world....

We often use the steam probe while wrestling on the floor with the neck.... (kidding of course about the floor part... kind of...) to get steam into the cheek joint for this reason.

Some iterations/vintages of guitars have more and some have less of the glue on the cheeks. It most certainly does make things more difficult.....

Not surprised about the neck block crack either, good going in finding it.
Author:  Pmaj7 [ Tue Nov 28, 2017 11:54 pm ]
Post subject:  Re: D-28 with cracked heel
Well, I got'er done! And it worked out pretty good. There was actually a crack in both sides of the neck block. I took Hesh's advice and charged for a neck reset and a half. (And threw in a free felt) Thanks for backing me up everyone, I really appreciate it! This was my biggest repair yet. I like building better, but the dollar ratio is pretty good with this type of thing.

I ended up leveling and recrowning from 12 down. They were a mess after the heat...


The only thing I would have done different is filled in some lacquer where the cracks were. As it was, I just sanded those areas through the grits and buffed them out. They felt good, but you could still see a bit of a fractured finish. I think it would be impossible to make them go away totally, but adding some lacquer probably would have helped.Image
Ebony smoke all in my brain...

ImageImageImage
ImageImageImage
Author:  Hesh [ Wed Nov 29, 2017 6:28 am ]
Post subject:  Re: D-28 with cracked heel
Way to go Pat! [:Y:]
Author:  Bryan Bear [ Wed Nov 29, 2017 10:40 am ]
Post subject:  Re: D-28 with cracked heel
This is certainly an under-educated question but. . . What's with the threaded insert in the dovetail?
Author:  david farmer [ Wed Nov 29, 2017 11:10 am ]
Post subject:  Re: D-28 with cracked heel
Bryan Bear wrote:
This is certainly an under-educated question but. . . What's with the threaded insert in the dovetail?



Dovetail = "Wing"
Bolt = "prayer"

:)

Good job Pat!
Author:  Bryan Bear [ Wed Nov 29, 2017 11:40 am ]
Post subject:  Re: D-28 with cracked heel
david farmer wrote:
Dovetail = "Wing"
Bolt = "prayer"
!


Ha!

I still don't get it though. I guess I have two questions. First, it seems like a bolt in that direction would negate a dovetail joint. Pulling the tenon into the body would pull the bearing surface of the dovetail away from the cheeks (unless I am just completely misunderstanding). Second, I don't see a bolt hole in the heel block. As far as I can tell there couldn't have been a bolt to go into the insert anyway. So, why did Martin put it there?
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