Official Luthiers Forum!

Sometimes I just scratch my head.

You may recall I asked before about the bridge plate on a gratis repair I'm doing for a friend. Well, I got the chance to dig into it and I can now say that I am determined in my life to never be a hack because of things like this.

As it came, nylon string bridge, 5 screws added, massive chunk of a bridge "plate"



The "plate"



Easy fix? I wish, I popped the bridge off with some heat and voila...



So this changes things quite a bit, will be updating this as I go along.

O.M.G.
Good luck, you'll need it.

_________________
"Act your age, not your shoe size" - Prince

Hey Dan. We never find the work in the repair business to be difficult but we do find the opportunities to take something in that might better be passed on never....... ending....... Danger Will Robinson.

A lot of one's perspective on what's to get excited about (and involved with...) and what's to be avoided (Ov*tions referred to the competitor that you like the least...) is also a function of what kind of Lutherie repair business you wish to run.

I've known people who will never understand that if you are attempting to pay bills and earn income maybe support a family being guarded against the "basket cases" if your market provides enough opportunity with repairs that are not basket cases is key. Actually in my experience one of the greatest occupational hazards to Luthiers is not learning when to decline on a repair.

We Luthiers decline, figuratively speaking and not just for Dave and I individually because there is never a shortage of bad jobs out there that cannot be estimated properly up front and will likely suffer from massive "scope creep...." There is also the you touch it you own it thing to be mindful of.....

For Luthiers who the opportunity costs, paying the bills and one's self don't matter, the not economically challenged variety... and who like endlessly toiling with fix one thing break two.... jobs it does not matter. For others it can make or break your business.

I have a credo of sorts with what I take in. The work has to have a defined beginning, a defined ending.... and a mutually agreed upon definition of success. Short of this I won't take the job in.

This year Dave put up a counter that we pull a cord every time we turn away a job. Jobs can be turned away for many reasons such as the economics (for the client) aren't present. An example would he a neck reset on a guitar that costs $200 to replace with a new one.... or someone who wants refinishing work, we don't do that and can't because of our proximity to eating establishments in the epicenter of a small city.

Our counter is reading in the 160s at present meaning that we turn away more than one instrument for every day that we are open. Interesting statistic.

My favorite is the guy who comes up and says look at what I "won....." on eBay for only $400. They produce an old Guild that needs a neck reset. Guilds suck for neck resets because they finished the things with the necks on so there is finish to cut back... AND the heel shape is so very small that they often break in the removal process.

When we tell the guy that his repairs, if done comprehensively and correctly with some fret work too since the fret plane gets messed up with resets will exceed what he paid for the thing and what he wants to flip... it for he's SOL and not all that happy.... It happens every day in our world.

Anyway it's been my experience that many of us have issues with declining and attempt to be all things to all folks. Then our businesses perish and we wonder why. Lutherie has never ending opportunities to hurt ourselves.... OTOH once we know this all the averages go up and we find ourselves making more and doing less.

One NYC Luthier who we know decided that he did not like certain jobs. I speak of fret work. So he decided to not do any of these jobs for a year and then look at his books and see if the business can sustain being "selective." He found out that he makes more money not doing the jobs that he dislikes. That's my point. This is also a real life story and some of you guys know who I speak of too.

Have fun and I hope that these are the kind of repairs that you like doing and can afford to do.

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Ann Arbor Guitars

You could think of it as an opportunity to improve your skills as an instrument chaplain.

It's a bigger part of the job than I ever thought it would be.

Part of cradle to grave service.

Hesh, you do have alot of experience in this area, and I do trust your judgement. So I am going to tackle this one sans a neck reset, that can be done later and I don't think he'll be playing it much outside of using a slide.

First order of business was to remove whatever the heck this block of junk was in the guitar.

So not wanting to put undue stress on the top, I opted for my sharpest little chisel in my collection and began to whittle away at the... thing.



I applied some small bits of water to the wood to soften it up and help it come out in chunks rather than splinters. Upon a couple of careful strokes I began to notice that it was coming out in layers of different grains. Plywood.





After a little bit of carefully cutting away it simply peeled away in a strip like so. You can see the other side of the chunk on the inside from this angle with the top layer removed. The previous "guy" hadn't even bothered to check if his glue joints were solid, there's a layer of unattached glue (epoxy perhaps) on the top of the bridge plate chunk you can see on the left side in the photo. The previous guy tried to glue a square joint with the endgrain of the top, no surprise it failed on him.



So, with that gone we move on to removing the chunk out of the guitar.

Now onto removing that chunk of a bridge plate overlay.

This was a bit of trouble for me, I have to come up with a way to remove the plate without damaging the top beyond what was already done (see the cracks in previous photos. Since I have no way of telling how much or what glue was used to attach it to the top, I opted to cut out a small swath of the plate, and use the top of the guitar to insert my tools under the top to work with the grain rather than reaching inside the top and working where I can't see what I'm doing as easily. The plan is to cut the chunk in two, and remove both parts separately in order to try to preserve the top and not risk massive amounts of pullout if I tried to remove it in one gigantic piece. Since the chunk will have severely less strength when cut in half, I feel I don't run the risk of unwanted top pullout if I remove it in smaller more controlled pieces since it won't be levering against the entirety of itself with the glue joints. Am I overthinking this? Probably.

I got out my smallest, sharpest, and most accurate dozuki saw and starting cutting. This is what I ended up with.



And guess what..... More plywood!



The next bit was using a mixture of water, vinegar, and some extremely careful movements of my pallet knife and a modified ruler I pressed into service for this repair. Doing it this way was much easier to work with the grain runout in mind than if I was inside the guitar.



I applied some heat via the heated up pallet knife to the glue bond and out came the giant chunk. And what remained of the original bridge plate was attached to it. There's a paper thin layer of mahogany on the bridge plate piece, ugh, was going for zero pullout and failed. The glue on the chunk was unknown but it looked like a pva glue.



The other half was a bit better glued in and came out in pieces. Now that I knew for sure the glue that was used wasn't epoxy I applied vinegar to help loosen the bond and coaxed it from it's place with no pullout but some slight scrape marks.

So here we sit with the debris cleared



And as Frank Ford once said, here we have the result of time, tension, and (COMPLETELY) inadequate repair.

You sir are a fine friend to this fellow.

That looks like one heck of a repair.

Thanks

Well done!

_________________
Steve Smith
"Music is what feelings sound like"

You're well on the way to making this into a silk purse!

Alex

_________________
"Indecision is the key to flexibility" .... Bumper sticker

Well done is right - good going Dan!

See what I mean as far as "scope creep..?" At some point it can get to the point where one wonders if retopping is prudent. When that happens it's a $2K+ job in opportunity costs for a busy shop.

Good to see these old instruments saved though so again good going my friend!

_________________
Ann Arbor Guitars

Saturday all the braces that had popped loose were reglued. Thankfully the original ones survived, still need to reglue two on the back but I have a tool on the way to help make that easier.

Now onto the bridge plate. When Gibson made these I learned that they simply used whatever they had on hand for the bridge plate material. So in light of that I decided to pay a little homage and use what I had on hand. In the form of this piece of maple I got for a steal at my local non-borg wood supply.



After some sawing and cutting I ended up with this little guy. I used what was left of the original bridge plate to measure out for the new plate. I didn't add any mass in thickness. However I did decide to extend it slightly further forward to help support the coming top graft. My little mini dozuki proved invaluable one I had cut the piece to thickness in making the corners nice and sharp. (thanks Hishika)





Next order of business was fitting the plate to the top/braces. Nice thing about having a giant hole through the top is the fact that you can see without mirrors what you're doing and make the needed adjustments. The original plate was not fit flush the braces, no surprise there given Gibson's workmanship at the time. I decided to try to make it as close as possible given the situation.

Final test fit showed it to be right where I wanted it, just a little more trim work and it'll be tight.


In the spirit of Kintsugi (look it up) I decided to add a little beauty and beveled the edges of the bridge plate. Honestly I don't know if this makes a different or not but it sure as heck looks alot better (to me anyway) than a flat cut on each edge.



So time to glue, hide glue is the order of the day. I didn't have a piece of acrylic big enough to cover the entire plate for clamping pressure so I cut a piece small enough to cover most of it, with 3 clamps I get even pressure and a large one in the middle will help keep the top flat. The double sided tape is great in cases like these where you have to move fast.

Glued up and clamped.





After the glue dried clamps were removed and here is the results. It's a bit of an improvement, just have to do the graft next.

You have it all well in hand...

_________________
"Act your age, not your shoe size" - Prince

I would have extended the plate forward to support the top due to the large hole. I know that is not the original design, but your top needs all the support it can get. Plus, it is routine to have the bridge plate extend fore and aft of the bridge footprint.

You are doing a great job - the instrument will be a treasure when it is done

I had never done anything like this but with some guidance from a couple of real luthiers I made a similar repair. The top started to change shape almost immediately after I strung it up, and a year later has what looks like a typical Gibson potato chip even though it has been tuned down 2 steps the entire time - D instead of E. I have been afraid to tune it up. Again, no expert, but I think probably adding 1/4"+ to the width of the bridgplate might help here - anybody? Sorry to be a day late with a comment:

https://www.flickr.com/photos/ruby1638/15266665930/in/album-72157646344222304/

With text below each shot,

Of course the solution might be a cast iron bridge plate:

Ed

Ed, I looked at the photos in the link you provided. If you look at the post I said that I did enlarge the bridge plate. It was also enlarged to insure that it met as flush as possible with the braces, the previous one when I did a dry fit was off by nearly an 8th in places. What I specified was that I didn't add mass in terms of thickness, not the area of the top that it occupies.

Also, you said made a similar repair, it crinkled up after you used the advice you got from the luthiers?

Mods please delete this post

Dan,

I'm with Barry and Ed on this. The question isn't if you made the bridge plate larger than the original. The question is why didn't you make it even larger to give full support to the patch you have to inlay in the top?

Steve

Mostly I thought I had added enough support to the top in what I had already enlarged on the plate.

Dan, may I suggest that in the future you post your proposed repair plans here to get the benefit of the vast experience of the collective, before proceeding. That is kind of why we are here.

Barry, there's no need to be smarmy towards me on this, I can easily remove the bridge plate and make a bigger one at this point, it's not a big deal.

I still have some of the maple left that I used before, nice thing is now I have an accurately sized (with the bracing in mind) full size bridge plate I can make adjustments to more easily.

"Also, you said made a similar repair, it crinkled up after you used the advice you got from the luthiers?"

Yes it did. My daughter, who owns her own repair shop (brooklynlutherie.com) said it is not as crinkled as some, but it seems awfully distorted. It is down a full 1/4" at the sound hole, and remember I have not taken it to full pitch in the last year. And mine did not have a hole all the way through. I wish someone who has done this successfully would speak up here.

Barry - judging by the way you phrased that comment, I think you should offer a solution

The trick is to get enough strength without adding so much weight that you kill the sound. you need to reconnect the lengthwise top fibers so they can resist the bridge rotation again.
A hardwood bridge plate is the wrong material for this. Spruce, spanning the horizontal fracture lines, grain running parallel with the top is the most efficient.
A typical sized bridge plate on top, (very slightly overlapping the bridge foot print front and back), will keep weight reasonable.

Here are some pic's of a repair I did similar to this. It was more or less copied from one John Arnold described over on the Martin Guitar forum. The spruce patch, if I remember, was some very wispy Engelman .060" thick. And only weighed a few grams. It tapered to almost nothing at the back.
A few years later I saw the guitar and it still looked a little too flat. I expected it to pull into a little more dome behind the bridge. That's with 13-56's on a dread. Further thinning at the back could still be done if desired. It's a lot easier to go that direction!

Not sure if spruce is a good idea on a hog top?

Sorry it didn't work out Dan.
As an isolated luthier, I find the exchange of Ideas on forums, even if sometimes contentious, invaluable.
I think most here genuinely want to help. Perhaps there was a misunderstanding of your initial post. I assumed you were looking for feedback/ help.
Good luck with the repair. I'm sure you'll find a way to get it done.