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David, I took no offense at what you said, in fact its a really good idea, let me rephrase myself.

With these different ideas being suggested at this point I'm not sure which one to follow. I can make a larger maple bridge plate or I can use your spruce technique.

My problem now is I have all these doubts about what I've already done and I'm just feeling like I need to undo what I've done and start over. I welcome the suggestions but it's driving me a bit nuts because I do want to do what's best. But now I'm not even sure I know what's best. Does that make sense?

Here's dealing with a similar situation http://theunofficialmartinguitarforum.y ... 6PI8DYUFFI

Clinchriver's link is a Good one.
Before I embarked on a repair like this I poked around a lot looking for what others had come up with. Just like your doing.

By far the deepest pool of ideas I found was searching past threads at the OMGF. Some truly exhaustive discussion's. Like this.http://theunofficialmartinguitarforum.yuku.com/topic/79822#.V6PjUI-cH4j

Your obviously going to have to sort through all the ideas and decide what makes the most sense in your situation. But the upshot of my experience is that something has to span and carry the load across the severed top grain. Either to take it to a brace, or disperse it smoothly to a large area. A bridge patch, even a huge one, is not well suited to the task. Letting the hardwood patch handle the string balls and light, strong, Spruce carry the load has worked well for me.

David

Thanks for your input - very helpful. That was a great thread by Willi. Interesting to see that after 4 weeks of string tension the top had moved so much, and that he had thought it was within the normal range. That technique would have been better for my repair.

Ed

So with all the information I removed the bridge plate I had made, it is significantly easier to do this with a huge hole cut in the top.

Ive decided to make a new bridge plate that spans the gap that the previous one fell short of. The top is going to be patched after the new plate is installed.

New bridge plate is complete, tomorrow I'll mix up some tea to stain it to help it lose some of that white "brand new" look.

I decided due to the advice of david farmer to orient the grain parallel with the top. Also I made the new plate to extend further forward underneath the area of severed wood for support (again, thanks to the advice from a few of the luthiers on here)

Tomorrow it will be glued in, and the work on the top graft will start.

Looking great Dan!!!

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We all get to learn something whenever someone has the courage to honestly share their work. That's the real beauty of the forum to me.
Thanks for posting and let us know how it turns out.

I've done it a few times the way the John Arnold method is described above and so far I have never seen any of those guitars come back and the first one I did like that was 15 years ago. Spruce - It's good stuff!

There was just a heated discussion over on the AGF about this actually. IDK why they always get heated. There is always more than one way to get the same job done.

The other method which is pretty slick actually is to make a scarf joint. So in the case of a mahogany top guitar you would shave out the top section around the hole, on the underside of the guitar, in a V shape - the scarf. The axis of the V is parallel to the bridge footprint. Then make a mahogany graft to fit in and then everything is flush. Then you just add the bridge plate.

You are indeed correct, there is always more than one way to get things done. I read that thread and the prevailing feeling I got from John Arnold was that he simply didn't want to be questioned on it, he did make a remark about another member's dyslexia that gave me pause. I don't post there just lurk and read the threads since like you stated they always get heated.

The issue I saw with the Arnold repair was that he never addressed the square joint in the top, also seems like he just redid the old repair, not sure why he did it that way, oh well, not my circus or monkeys. In the case of this guitar I'm following in the footsteps of a few other repair guys namely Frank Ford who did an almost exact copy of this repair on a D28 that he did a repair journal on.

http://frets.com/FretsPages/Blogs/40D28/40d28_1.html

In Mr. Ford's repair, he simply made the bridge plate bigger to cover the severed fibers, then inlaid the top over the bridge plate with a scarf joint on both ends. That is my plan for this one, albeit I have a much larger hole and a much larger bridge plate to work with. In my furniture building a well done joint is stronger than the wood itself, so we'll make it happen one way or another.

[quote="DanKirkland"][quote="jfmckenna"]I've done it a few times the way the John Arnold method is described above and so far I have never seen any of those guitars come back and the first one I did like that was 15 years ago. Spruce - It's good stuff!



You are indeed correct, there is always more than one way to get things done. I read that thread and the prevailing feeling I got from John Arnold was that he simply didn't want to be questioned on it, he did make a remark about another member's dyslexia that gave me pause. I don't post there just lurk and read the threads since like you stated they always get heated.

The issue I saw with the Arnold repair was that he never addressed the square joint in the top, also seems like he just redid the old repair, not sure why he did it that way, oh well, not my circus or monkeys. In the case of this guitar I'm following in the footsteps of a few other repair guys namely Frank Ford who did an almost exact copy of this repair on a D28 that he did a repair journal on.

I'm going to step in on this, John Arnold is one of the nicest most helpful knowledgeable person I have ever met. He very succinctly explained his method (over 100 guitars successfully repaired) He does take some to task for mis-use of the english language and the abrasive repair person on the other forum admitted towards the end of the thread to being dyslexic. But where did he mention anything negative about anyone with dyslexia?

I really don't want to derail this thread. John essentially put a link up to be smart alecky to the other guy to a page that explained the "there their they're" thing since he misspelled one word in another unrelated thread. I have no dog in this fight, just calling it like I see it. There's two other highly skilled luthiers disagree with him (Howard Klepper and Bruce Sexauer) so there's something going on, what it is I don't know (and frankly I don't care), I'm more interested in my own projects than trying to correct people on the internet. That's all I want to say about this matter. John can repair guitars his way, and I'll repair mine the way I see fit, no problem made no problem seen.

Today I got ahold of some mahogany that's not quite a perfect grain match, but it'll finish close to the original.

There is going to need to be some finish touchup around the edges, I had considered using some clear shellac with some transtint added to get the right shade of brown. Thoughts?

I think shellac is the next best thing to sliced bread when it comes to finish touch up. Sticks to anything, can be dyed, and even polished to a nice gloss.

Thanks for the tip John

I have been struggling to get a perfect fit on the scarf joint. How much tolerance can you work with on a slight bevel for the joint? I know hide glue doesn't fill gaps at all. I have it sitting flush with the bridge plate but I can't seem to get the sides to line up dead on no matter what I do. Any advice?

One idea you might find helpful.
Either fit the scarfed piece from a thicker block and slice it off after fitting, or stick your thinner piece to a stiffer backing piece while fitting.

David, that is very helpful thanks! Fixed alot of issues for me.

One thing I have been thinking about is the bridge. I have never made a bridge and I have been on the fence about whether to use a pre-made bridge such as the SM pyramid bridge and simply do touchup work with shellac, or to try to make one, if I do make one it would have to be seriously oversized to cover the area of the finish damage from the previous work, it'd have to be as big and as wide as a classical bridge and in my opinion when bridges are that oversized they look out of place. I don't have a palm router and I can't afford one right now for slotting the saddle. thoughts on this issue?

The first graft went in tonight, I didn't have a piece of mahogany wide enough to get a single large graft for the entire hole. So it'll have to be two grafts that are scarfed together.

So this instrument has been strung up for about 3 days at this point. I neglected get photos of the grafting process but needless to say I found quite a few other gouges out of the top that I hadn't noticed before that needed to be filled. As a result the look isn't as perfect as I'd like and you can see some of the grafts if you look closely. However everything is reversible as the only glue that was used was HHG. It has a nice woody boxy sort of sound to it.

Only part I didn't make was the bridge, I ended up having to go with an SM bridge for it since making a bridge is something I do not have the skills to accomplish at this current time. The instrument sounds nice and doesn't have too much of a potato chip top but it has some of the usual shapes that Gibbys of this era get after a while. The neck angle isn't too terrible but it will need a neck reset to make it optimal, but as a cowboy chord strummer it's not too bad nor as a slide instrument.

Thanks for everyone who lent a hand in helping me get this one playing again. The owner was thrilled to have his grandfathers old guitar back and playing again.

Looks good and provided plenty of experience.

Ed

Thanks Ed, and thanks for your help as well

Nice save Dan!!!!!

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Ann Arbor Guitars

Well done, sir!

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Just for later reference: Spruce is great for a bridge plate Dan, pick a stiff, tough piece, and make it a bit thicker than a Maple one, say .125" to .130"

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wow this thread is a blast from the past. I still remember that guitar oddly enough. To my knowledge it's still being played by the owner.